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  • 1.
    Azimoh, C. L.
    et al.
    University of Johannesburg, Department of Quality and Operations Management, Faculty of Engineering and Built Environment, Johannesburg, South Africa.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mbohwa, C.
    University of Johannesburg, Department of Quality and Operations Management, Faculty of Engineering and Built Environment, Johannesburg, South Africa.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Replicability and scalability of mini-grid solution to rural electrification programs in sub-Saharan Africa2017In: Renewable Energy, ISSN 0960-1481, Vol. 106, 222-231 p.Article in journal (Refereed)
    Abstract [en]

    The assessment of off-grid electrification programs in developing countries largely based on mini-grid and solar home system (SHS) has shown that they are faced with low development imparts and sustainability challenges, which has resulted in failure of many projects. This study provides solutions on how to surmount these challenges, leaning on the experience of a hybrid solar-diesel mini-grid at Tsumkwe village in Namibia. It provides analyses of a case study based on empirical evidence from field studies, interviews of representatives of households, public institutions and energy providers. In addition, it investigates the technical challenges and economic impacts of the electrification program. HOMER™ and MATLAB™ models were used in the analysis and investigations. The findings show that despite the challenges, the system has been sustained because it keyed into an existing structure with growth potentials. The progressive tariff system adopted by the government helped to cushion costs and allow low income households in the energy matrix. Adoption of strict maintenance measures, and implementation of energy efficiency measures prior to the commissioning of the program, resulted in the reduction of costs. The success elements identified in this study could be extrapolated in other sub-Saharan African countries if the challenges are properly addressed.

  • 2.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Illuminated but not electrified: An assessment of the impact of Solar Home System on rural households in South Africa2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 155, 354-364 p.Article in journal (Refereed)
    Abstract [en]

    The introduction of the off-grid electrification program in South Africa using the Solar Home System (SHS) was a central component of the government policy aimed at bringing development to un-electrified households. An assessment of the performance of SHS in many countries provided little evidence to support the development impact of the system. The general perception is that the SHS program is wasting government funds and has no hope of achieving the set objectives. Previous scientific reports have concluded that SHS is the most viable technology for bringing about socio-economic development to rural households. Most of these conclusions have been based on one sided arguments and largely on anecdotal evidence. This study provides a pluralistic view of the subject from the perspective of the energy service companies (ESCOs) and the households using the equipment. The development impact of SHS is subjected to scientific analysis by investigating the economic and social dimensions of the program. Additionally, the sustainability of the South African SHS program is assessed by investigating the challenges facing the ESCOs and the households. The study reveals that illumination provided by SHS electricity has profound impact on the livelihoods of rural households. Due to the limited capacity of SHS for productive and thermal use, there are limited direct economic benefits to the households. The associated economic impact is peripheral to the secondary usage of SHS electricity. SHS has improved the productivity of small scale business owners who utilize the light from SHS to do business at night. Irregularities in payment of subsidy funds and energy bills, high operation cost, non-optimal use of SHS, grid encroachment, and lack of customer satisfaction contribute to make the business unsustainable for the ESCOs.

  • 3.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    The burden of shading and location on the sustainability of South African solar home system program2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, 308-313 p.Article in journal (Refereed)
    Abstract [en]

    Most contributions on the issues of sustainability of rural electrification projects have focused on the technology and business models used to drive the projects. The issues of user education and environmental impact on the technology have received little attention, despite the fact that these challenges affect lives of projects after commissioning. The usage pattern of solar home systems (SHS) by most users that placed their solar panels close to obstructing objects, results in shading of the panels, and geographic location of households in the concession areas of the South African SHS program affects the performances of the system. The non-optimal use of SHS is mainly due to lack of user education. Therefore this paper reports on the impact of geographic location and shading of panels on the economics and technical performance of SHS. The study was done by investigating the performance of 75 WP solar panels operated at two sites in South Africa (Upington in Northern Cape Province and Thlatlaganya in Limpopo Province), the performance of an optimized shaded SHS and a non-shaded one was also investigated. The results show that both geographic location and shading compromise the performance of the systems, the energy output of a solar panel located at Upington is increased by 19% and the state of charge of the battery (SOC) increased by 6%, compared to the panel situated at Thlatlaganya village. Also the life span of the battery is increased by about one year. The SOC of the partially shaded SHS is reduced by 22% and loss of power to the load increased by 20%. The geographical location of the SHS concession areas in South Africa and lack of adherence to the manufacturer's installation specification affects the economics of SHS and the energy output vis-a-vis the sustainability of the program due to reduction in life cycle of the batteries. 

  • 4.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Mbohwa, Charles
    University of Johannesburg, South Africa.
    Electricity for development:: Mini-grid solution for rural electrificationin South Africa2016In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, no 110, 268-277 p.Article in journal (Refereed)
    Abstract [en]

    The objective of most rural electrification programs in the developing world is to bring about socioeconomicdevelopment to households. Governments have put in place a number of measures to achievethis goal. Previous studies on rural electrification programs in developing countries show that solar homesystems and mini-grid systems are the dominant technologies. Assessments of a pilot hybrid mini-gridproject at Lucingweni village have concluded that mini-grid projects are not feasible due to high electricityproduction costs. As a result efforts toward rural electrification have been focused on the solar homesystem. Nevertheless, previous studies of the South African solar home system program have shown thatthe development objectives of the program are yet to be met more than a decade after commissioning.Therefore, this study investigates the viability of a hybrid mini-grid as a solution for rural developmentin South Africa. Investigations were based on Lucingweni and Thlatlaganya, two rural Villages where themini-grid and solar home system have been introduced. The mini-grid systems were designed taking intoconsideration available natural resources and existing load profiles. The results show that a village of 300households needs about 2.4 kW h/household/day of electricity to initiate and sustain income generatingactivities and that the solar home system is not capable of supporting this level of demand. We also showthat in locations with hydro resources, a hybrid mini-grid system has the most potential for meeting theenergy needs of the households in a cost effective manner. The assessment shows that with adequateplanning and optimization of available resources, the cost of electricity production can be reduced.

  • 5.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    An assessment of unforeseen losses resulting from inappropriate use of solar home systems in South Africa2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 136, 336-346 p.Article in journal (Refereed)
    Abstract [en]

    One of the challenges to the sustainability of the Solar Home System (SHS) electrification program in South Africa is equipment theft. In response to this, communities susceptible to solar panel theft resort to mounting their panels flat on the ground so they can be looked after during the day and taken indoors at night for safe keeping. Other households use their security lights to illuminate their environment and provide security for pole and roof mounted solar panels at night. These actions have consequential effects on the performance of the SHS. Several studies have detected resentment from households regarding the low power quality from these systems. Most scientific contributions on the issue of low power from SHS have focused on the challenges based on the technical designs of the systems. The power losses due to the usage pattern of the system has not received much attention. This study therefore reports on the technical losses as a result of the deviation from the designed and installed specification of the system by the users in order to protect their systems. It also investigates the linkage between the technical and economic losses which affects the sustainability of SHS program. A case study was performed in Thlatlaganya village within Limpopo province in South Africa. Technical analysis using PVSYST solar software revealed that the energy output and performance of the battery is compromised as a result of these practices. Economic analysis indicates that the battery life and the economics of owning and operating SHS are affected negatively. The study recommends solutions to mitigate these losses, and proposes a cost effective way of optimizing the operation of SHS using a Bench-Rack system for mounting solar panels.

  • 6.
    Azimoh, Chukwuma Leonard
    et al.
    Mälardalen University, School of Innovation, Design and Engineering.
    Wallin, Fredrik
    Mälardalen University, School of Innovation, Design and Engineering.
    Oyedokun, D.
    University of Cape Town, Rondebosch, CT, South Africa.
    Bridging the electrification gap in the sub-Saharan Africa2012In: World Renewable Energy Forum, WREF 2012, 2012, 4426-4433 p.Conference paper (Refereed)
    Abstract [en]

    Studies have shown that Africa has enough resources to meet the continent's energy need and beyond. Statistics has it that only about 3.5% of world oil produced is consumed in the continent, whilst at the same time the continent contributes about 12.5% of the total world oil production. Africa also has capabilities for hydro, solar, geothennal. and biomass energy etc. Despite all these, Africa is still lying prostrate in meeting the energy need of its bourgeoning population. Many papers in the power literature have proffered solutions using fossil based energy technology as a panacea for meeting the short fall; others used renewable energy based solutions, but there has been a protracted history of failures. The adduced reasons borders on ineffective policies and business models. This paper therefore investigates the various renewable technologies as well as fossil based energy systems with the interest of identifying reasons for their failures in the past. The paper also reports on various policies on renewable energy in Africa that militates against energy sector development. Taking a holistic view of the cotemporary Africa situation in terms of its energy needs, it is the believe of the authors that, to overcome the energy challenges in Africa, an optimal response strategy that combines grid based and decentralized off-grid small scale renewable systems should be adopted. To this extent, our solution will not only augment with the existing solutions in providing the much needed electricity to the rural/peripheral urban dwellers in Africa, but also alleviate the poverty level through creation of jobs.

  • 7.
    Azimoh, Leonard
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering.
    Nehrenheim, Emma
    Mälardalen University, School of Business, Society and Engineering.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering.
    Chowdhury, S.P.
    University of Cape Town.
    Chowdhury, Sunetra
    University of Cape Town.
    Using Renewable Energy Paradigm as a Tool for Sustainable Village Concept (SVC) in Africa2012Conference paper (Refereed)
  • 8.
    Bartusch, Cajsa
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Larsson, Mikael
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wester, Lars
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Potential of hourly settlements in the residential sector of the Swedish electricity market: Estimations of risk reduction and economic result2010In: International Journal of Green Energy, ISSN 1543-5075, Vol. 7, no 3, 224-240 p.Article in journal (Refereed)
    Abstract [en]

    Increased demand response is essential in order to boost the effectiveness of the Swedish power market. The all-embracing installation of automatic meter reading systems enables power suppliers to introduce hourly settlements in the residential sector. The aim of the study has been to assess the impact of electricity retailers’ physical and financial risk in customer segments with different heating systems as well as to estimate the potential of the electricity contract ”Fixed price with the right to return” in terms of economic consequences and risk management. The results show that households whose main heating system consists of a geothermal heat pump constitute the largest physical price and volume risk of suppliers. The gain of introducing hourly settlements in the residential electricity market has furthermore proven to be manifold from both an economic and risk reducing point of view.

  • 9.
    Bartusch, Cajsa
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Odlare, Monica
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Electricity consumption and load demand in single-family house2008Conference paper (Refereed)
  • 10.
    Bartusch, Cajsa
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Odlare, Monica
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wester, Lars
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Exploring variance in residential electricity consumption: Household features and building properties2011In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 92, 637-643 p.Article in journal (Refereed)
    Abstract [en]

    Improved means of controlling electricity consumption plays an important part in boosting energy efficiency in the Swedish power market. Developing policy instruments to that end requires more in-depth statistics on electricity use in the residential sector, among other things. The aim of the study has accordingly been to assess the extent of variance in annual electricity consumption in single-family homes as well as to estimate the impact of household features and building properties in this respect using independent samples t-tests and one-way as well as univariate independent samples analyses of variance. Statistically significant variances associated with geographic area, heating system, number of family members, family composition, year of construction, electric water heater and electric underfloor heating have been established. The overall result of the analyses is nevertheless that variance in residential electricity consumption cannot be fully explained by independent variables related to household and building characteristics alone. As for the methodological approach, the results further suggest that methods for statistical analysis of variance are of considerable value in indentifying key indicators for policy update and development.

  • 11.
    Bartusch, Cajsa
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Odlare, Monica
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Iana, Vassileva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wester, Lars
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Introducing a demand-based electricity distribution tariff in the residential sector: demand response and customer perception2011In: Energy Policy, ISSN 0301-4215, Vol. 39, no 9, 5008-5025 p.Article in journal (Refereed)
    Abstract [en]

    Increased demand response is essential to fully exploit the Swedish power system, which in turn is an absolute prerequisite for meeting political goals related to energy efficiency and climate change. Demand response programs are, nonetheless, still exceptional in the residential sector of the Swedish electricity market, one contributory factor being lack of knowledge about the extent of the potential gains. In light of these circumstances, this empirical study set out with the intention of estimating the scope of households’ response to, and assessing customers’ perception of, a demand-based time-of-use electricity distribution tariff. The results show that households as a whole have a fairly high opinion of the demand-based tariff and act on its intrinsic price signals by decreasing peak demand in peak periods and shifting electricity use from peak to off-peak periods.

  • 12.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Odlare, Monica
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stigson, Peter
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Buildings in the future energy system: Perspectives of the Swedish energy and buildings sectors on current energy challenges2015In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 107, 254-263 p., Article number 6090Article, review/survey (Refereed)
    Abstract [en]

    Buildings are expected to play a key role in the development and operation of future smart energy systems through real-time energy trade, energy demand flexibility, self-generation of electricity, and energy storage capabilities. Shifting the role of buildings from passive consumers to active players in the energy networks, however, may require closer cooperation between the energy and buildings sectors than there is today. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this study presents the views of the energy and buildings sectors on the current energy challenges in a comparative approach. Despite conflicting viewpoints on some of the issues, the energy and buildings sectors have similar perspectives on many of the current energy challenges. Reducing CO2 emissions is a shared concern between the energy and buildings sectors that can serve as a departure point for inter-sectoral cooperation for carbon-reducing developments, including the deployment of smart energy systems. The prominent energy challenges were identified to be related to low flexibilities in energy supply and use, which limit mutually beneficial cases, and hence cooperation, between the energy and buildings sectors today.

  • 13.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Buildings as components of smart grids - Perspectives of different stakeholders2014In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, 1630-1633 p.Article in journal (Refereed)
    Abstract [en]

    This paper provides the perceptions of the energy and buildings sectors, municipalities and researchers in Sweden about active buildings that provide smart grid services to their inhabitants. As part of this study, we conducted 23 semi-structured interviews with key stakeholders to present the perspectives of stakeholders that are involved in the development process. Our study shows that there are several barriers to development of active buildings and points out the importance of energy policy mechanisms to support the development. It is necessary to introduce new measures in order to financially encourage the stakeholders and motivate the end-users to invest in smart grid technologies. The elimination of the intersectoral barriers and the promotion of cooperation amongst stakeholders could pave the way for a more efficient and smarter grid.

  • 14.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Karlsson, Björn
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    The role of buildings in the energy system: Intersectoral barriers to future developments2013In: The role of buildings in the energy system - intersectoral barriers to future developments, 2013Conference paper (Refereed)
    Abstract [en]

    Residential energy consumption has a significant share in the final energy use in Sweden. Despite this relationship, it is hard to say that there is cooperation between the building and energy sectors for energy issues in buildings. In the grid of the future, buildings will no longer be a passive element of the electricity system; instead, they will acquire an active role in the operation of the grid. The cooperation between the building and energy sectors could play a key role for a successful development of smart grid technologies in buildings.In this paper, we describe the Swedish case and analyse the barriers to cooperation between the energy and building companies with the help of interviews with several stakeholders. This study showed that there is a demand for new business models in order to accommodate smart grid developments in buildings. Collective projects and new roles that reduce the power differences and barriers between the two sectors could contribute to the cooperation and support the development of future energy services in buildings.

  • 15.
    Bulut, Mehmet Börühan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stigson, Peter
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Cooperation for climate-friendly developments: An analysis of the relationship between the energy and buildings sectors in Sweden2016In: Energy Efficiency, ISSN 1570-646X, E-ISSN 1570-6478, Vol. 9, no 2, 353-370 p.Article, review/survey (Refereed)
    Abstract [en]

    Buildings account for more than 40 % of the total energy demand in the European Union (EU). The energy sector is responsible for 80 % of the total greenhouse gas emissions in the EU, of which more than a third are emitted as a result of energy use in buildings. Given these numbers and the large potential for energy savings in buildings, the energy and buildings sectors emerged as key contributors to fulfilling the European climate targets. Effective cooperation between these two key sectors can contribute significantly to the efficacy of the European climate strategy. However, there may be factors that negatively impact the relationship between the energy and buildings sectors and put cooperation in climate-friendly developments at risk. Based on 23 semi-structured interviews and a web survey answered by key stakeholders, this paper provides a snapshot of the current level of cooperation between the energy and buildings sectors in Sweden and identifies factors that impact the interdependencies between the two sectors.

    The findings show that the current business models in energy supply and the regulations in place limit the development of mutually beneficial cases between the energy and buildings sectors. This paper contributes to improved knowledge for policymaking that affects both sectors and highlights issues for further study.

  • 16.
    Bulut, Mehmet
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Odlare, Monica
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stigson, Peter
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Active buildings in smart grids - Exploring the views of the Swedish energy and buildings sectors2016In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 117, 185-198 p.Article in journal (Refereed)
    Abstract [en]

    The development of smart grids is expected to shift the role of buildings in power networks from passive consumers to active players that trade on power markets in real-time and participate in the operation of networks. Although there are several studies that report on consumer views on buildings with smart grid features, there is a gap in the literature about the views of the energy and buildings sectors, two important sectors for the development. This study fills this gap by presenting the views of key stakeholders from the Swedish energy and buildings sectors on the active building concept with the help of interviews and a web survey. The findings indicate that the active building concept is associated more with energy use flexibility than self-generation of electricity. The barriers to development were identified to be primarily financial due to the combination of the current low electricity prices and the high costs of technologies. Business models that reduce the financial burdens and risks related to investments can contribute to the development of smart grid technologies in buildings, which, according to the majority of respondents from the energy and buildings sectors, are to be financed by housing companies and building owners. 

  • 17.
    Campillo, Javier
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Is real-time electricity pricing suitable for residential users without demand-side management?2016In: Energy Journal, ISSN 0195-6574, E-ISSN 1944-9089, Vol. 109, 310-325 p.Article in journal (Refereed)
    Abstract [en]

    The smart metering infrastructure in Sweden allows electricity providers to offer electricity RTP (real time pricing) to homeowners, together with other dynamic pricing contracts across the country. These contracts are supposed to encourage users to shift power consumption during peak hours to help balance the load in the power system. Of all the available contracts in Sweden, monthly-average price holds the largest share, in response to the low electricity prices during the last three years. It is not clear if RTP will become a popular dynamic pricing scheme since daily price fluctuations might keep customers away from this type of contract. Literature review suggests that RTP adoption is only beneficial when combined with the use of customer demand flexibility, but it does not provide enough information about users adopting RTP without changing their electricity usage profile. This paper studies the economic impact if customers would shift to RTP contracts without adopting demand-side management. To achieve this, electricity costs from a large group of households were calculated and compared between both pricing schemes using the hourly consumption data of a 7-year period. Results suggest that the RTP electricity contract offer a considerable economic savings potential even without enabling consumer demand-side management. 

  • 18.
    Campillo, Javier
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering.
    Torstensson, Daniel
    Mälardalen University, School of Business, Society and Engineering.
    Vassileva, Iana
    Facultad de Ingeniería, Universidad Tecnológica de Bolívar, Cartagena, Colomb.
    Energy Demand Model Design for Forecasting Electricity Consumption and Simulating Demand Response Scenarios in Sweden2012In: / [ed] J. Yan, 2012Conference paper (Refereed)
    Abstract [en]

    The introduction of a deregulated power system market and development of smart-metering technologies in Sweden, bring new opportunities for fully exploiting its power system efficiency and reliability, such as price-based demand response (DR) programs at a large scale for household, commercial and industrial users. 

    The deployments of these DR programs require, however, very accurate demand forecasting models. The traditional approach of obtaining the total energy use and peak demand does not offer the required detailed information. This article reviews several methodologies for forecasting electricity consumption from a bottom-up perspective in order to define the required parameters and structure for obtaining an energy model. This model will finally include energy usage data, behavioural parameters obtained from a survey conducted with 5 000 end-users in different Swedish distribution system operators’ areas, and physical conditions for the facilities (internal/external temperatures and insulation materials). This information is provided from previous research studies performed at Mälardalen University and Swedish electric utilities companies. 

    The obtained model should be able to adjust its parameters dynamically in order to simulate several demand-response scenarios based on four different strategies: time of use pricing, use of curtailable/interruptible rates, imposition of penalties for usage beyond predetermined levels, and real time pricing.

  • 19.
    Campillo, Javier
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Vassileva, Iana
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Economic Impact of Dynamic Electricity Pricing Mechanisms Adoption fo rHouseholds in Sweden2013Conference paper (Refereed)
    Abstract [en]

    Global smart metering market growth has increased significantly over the past few years and the trend is expected to continue. Smart metering technology enables energy consumption feedback and the adoption of dynamic pricing mechanisms that encourages users to shift power consumption from peak-use times to lower-use times, in order to help balance the load in the power system. In Sweden particularly, the introduction of the new legislation and adoption of remote meters in 2009, in combination with more flexible pricing schemes, offer a great opportunity for users to reduce energy consumption during peak times, increase their energy efficiency and therefore reduce their overall cost. More recently, in 2012, Swedish energy providers started offering hourly spot-based electricity price to homeowners in order give them access to pricing mechanisms that are closer to the real cost of electricity supply. Additionally to hourly pricing, other dynamic pricing contracts are available for consumers all across the country; however, conventional agreements that use fixed-rates for electricity are still the most common. This paper analyzes the economic impact for consumers, if dynamic pricing, enabled through smart metering technologies, is adopted. To achieve this, electricity costs from a large group of households were calculated, using users’ hourly consumption data with both conventional fixed rates and real time pricing, in order to understand their impact on customers’ bills. Obtained results suggest that real time pricing has great savings potential, especially for years where summer rainfall and winter conditions are within average. However, in order to increase savings and have them consistent year after year, changes in user time-of-use consumption profile are required. Moreover, this research work leads to further analysis on dynamic pricing combined with demand response in order to optimize electricity costs.

  • 20.
    Campillo, Javier
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Electricity Demand Impact from Increased use of Ground Sourced Heat Pumps2012In: IEEE PES Innovative Smart Grid Technologies Conference Europe, 2012, Artnr. 6465876- p.Conference paper (Refereed)
    Abstract [en]

    The use of ground-sourced heat pumps as main heating systems has increased in Sweden in the last fifteen years to the point that it is the country with the highest amount of GSHP in Europe. Heat pumps are chosen by many households due to their economic savings value; In contrast, electricity prices in Sweden have almost doubled since 2006, threatening their economic benefits. It is therefore, essential to understand GSHPs impact on the user´s electricity consumption and provide suitable demand-response programs that could help develop a model capable of forecasting consumption and provide decision support information to make the best use of the technology. This paper analyses questionnaire surveys and consumption patterns were evaluated for 322 households with installed GSHPs and different pricing schemes in order to increase the understanding of mass use of this type of heating system.

  • 21.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    How to save energy to reach a balance between production and consumption of heat, electricity and fuels for vehicles2011In: International Green Energy Conference (IGEC-6) Anadolu University / [ed] Hikmet Karakoc, Eskeshir, 2011Conference paper (Refereed)
    Abstract [en]

    There is a potential to utilize a significant amount of renewable energy in Sweden and EU. Biomass can fulfil some 8 500- 12 500 TWh/y in EU, while the total utilization was 16 084 TWh/y 2009. Even though there is a significant amount of wind power, hydro power and potentially also solar power, it still is most economical to reduce the consumption of heat, electricity and fuels for vehicles. A saved kWh is normally cheaper than to produce one extra. In this paper different opportunities for saving energy will be discussed. This includes manufacturing industries, process industries, power plants and energy systems including distribution of power and smart grids, food production and transportation. There is also a major potential to save energy in buildings, both in the north where it is cold, and in the south where it can be very hot summertime. Here the potential is to avoid cooling instead. Technical solutions as well as economic incentives will be covered. Environmental aspects will be addressed, so that the solutions will be long term sustainable.

     

  • 22.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    How to save energy to reach a balance between production and consumptionof heat, electricity and fuels for vehicles2012In: Energy, ISSN 0360-5442, Vol. 46, no 1, 16-20 p.Article in journal (Refereed)
    Abstract [en]

    There is a potential to utilize a significant amount of renewable energy in Sweden and European union(EU). Biomass can fulfil some 8500e12,500 TW h/y in EU, while the total utilization was 16,084 TW h/y2009. Even though there is a significant amount of wind power, hydro power and potentially also solarpower, it still is most economical to reduce the consumption of heat, electricity and fuels for vehicles. Asaved kWh is normally cheaper than to produce one extra. In this paper different opportunities for savingenergy will be discussed. This includes manufacturing industries, process industries, power plants andenergy systems including distribution of power and smart grids, food production and transportation.There is also a major potential to save energy in buildings, both in the north where it is cold, and in thesouth where it can be very hot summer time. Here the potential is to avoid cooling instead. Technicalsolutions as well as economic incentives are covered. Environmental aspects are addressed, so that thesolutions will be long term sustainable.

  • 23.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    OPTIMIZATION OF THE ENERGY SYSTEM TO ACHIEVE A NATIONAL BALANCE WITHOUT FOSSIL FUELS2011In: International Journal of Green Energy, ISSN 1543-5075, Vol. 8, no 6, 684-704 p.Article in journal (Refereed)
    Abstract [en]

    In this article, the overall energy balance for Sweden and to some extent EU27 is discussed. It deals with the reduction of the total consumption in industrial, transport, and domestic sectors through more efficient vehicles, industrial processes, and buildings and individual behavior. The conclusion is that it should be relatively easy for Sweden to reach a sustainable society if the political will, in the form of policies and incentives, is present. It would also be possible for the EU27 to reach a sustainable society, although it would be more demanding (challenging?).

  • 24.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Optimization of the energy system to achieve a national balance without fossil fuels2010In: International Green Energy Conference, IGEC-V June 1-3, 2010, Waterlo, Ontario, Canada / [ed] Xianguo Li, Waterloo,Canda: University publications , 2010Conference paper (Refereed)
    Abstract [en]

    In this paper we discuss the overall balance for Sweden and to some extent EU27 with respect to both power and heat production in relation to how the energy is utilized. This includes transportation, where we compare the system of today with a possible future system with hybrid-electric vehicles, renewable fuels and reductions of total consumption, through both better vehicles, as well as better logistics for transportation of goods. Concerning industry use energy improvements through more efficient industrial processes is discussed. For households, offices and manufacturing industries energy efficient buildings and individual behavior with respect to energy use is discussed. New sources for power will be less stable, like wind and solar power. A special focus is on biomass utilization and production. This also includes food. The situation today is compared to the potential balance after implementation of the actions discussed in the paper. The overall conclusion is that it should be relatively easy for Sweden to reach a sustainable society, if just the political will is present. It is also shown that there is a good potential also for the complete EU 27, but the actions are significantly more demanding to reach the balance, although in no way impossible.

  • 25.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Dhak, Janice
    Mälardalen University, Department of Public Technology.
    Experiences of on-line and off-line simulation in Pulp and Paper industry2004In: Proceedings of the PTS-symposium, 2004Conference paper (Other (popular science, discussion, etc.))
  • 26.
    Dahlquist, Erik
    et al.
    Mälardalen University, Department of Public Technology.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Ekwall, Håkan
    ABB Industry, Västerås, Sweden.
    Dynamic simulators for process control and optimization as well as for operator training in pulp and paper industry2002In: Proceedings of the 43rd Conference on Simulation and Modelling: SIMS 2002, 2002Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    By using a dynamic physical model, that is adapted to real process data, robust mathematical process models can be created. By doing this it is possible to build in process know how from many different sources, and also to include factors, that are not easy to measure. From the dynamic model a training simulator can be made. From the dynamic model it may also be possible to do a model reduction to get an MPC, a Model Predictive Control. Data reconciliation is needed, to keep control of the measurements of all kind. A decision support system keeps control over the process status, to support operators. The production is also optimized at several levels. These functions may also be achieved by using principally the same mathematical models and algorithms.

  • 27.
    Dahlquist, Erik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Karlsson, Björn
    Mälardalen University, School of Sustainable Development of Society and Technology.
    A fossil fuel free Europe need new incentives and a better control to balance power production and demand2011In: SAUPEC 2011 July 13-15 at Cape Town University, South Africa / [ed] SP Chowdrury, Cape Town: Cape Town University Press , 2011Conference paper (Refereed)
    Abstract [en]

    In EU27 today there is a production of approximately 1000 TWh/ electric power from nuclear and 350 TWh/y from hydro power. The solar power potential is probably around 200 TWh/y. The wind power production is approximately 100 TWh/y but with a potential of at least 1000 TWh/y. The total biomass resources available are in the range 8500-12000 TWh/y. This gives a total of 10 000 – 15 000 TWh/y, from which at least 4000 TWh/y as electric power. This can be compared to the present gross energy use in EU 27 that was 16 084 TWh 2009, and 3400 TWh/y electric power. We can also see that there is a potential to save approximately 4 200 TWh/y in households, offices, transportation and industry. The energy balance thus should be possible to obtain with only non-fossil energy resources. Another matter is the power in time and by region. The demand does not always match the production locally at each moment and this demands a robust transmission and distribution network. Therefore we need new business models making it attractive for the users to reduce the load when there is a difficulty to deliver.

  • 28.
    Damir, Isovic
    et al.
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering. Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Gustafsson, Christine
    Mälardalen University, School of Health, Care and Social Welfare, Health and Welfare.
    THE COPRODUCTIVE UNIVERSITY: Education and research in coproduction with the wider community2013Conference paper (Refereed)
    Abstract [en]

    Mälardalen University has a long history of a successful cooperation and coproduction with the industry and public sector in Sweden. This has eventually led it to become one of the leading higher education institutes in Sweden for excellent coproduction with different societal actors, both internationally and nationally. The university has through its coproduction activities become convinced of its value and of the wide range of opportunities it can bring to all parties involved. In this paper, we share our experience through some good examples both from research and education and discuss what is needed for successful and sustainable coproduction with industry and public sector.

  • 29.
    Ding, Y.
    et al.
    Karlsruhe Institute of Technology.
    Decker, C.
    INIT GmbH, Germany.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Beigl, M.
    Karlsruhe Institute of Technology.
    A Smart Energy system: Distributed resource management, control and optimization2011In: IEEE PES Innovative. Smart Grid Technol. Conf. Europe, 2011Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel concept of distributed energy resource and consumption management, which proposes to design a networked and embedded platform for realizing a dynamic energy mix and optimizing the energy consumption dynamically. Based on heterogeneous wireless sensor networks and a local Web of Things platform, the environmental parameters and energy data can be acquired and processed in a distributed manner in real time. In order to improve understanding on how different environmental factors and user behaviors influence the end use of energy, we propose a User Profiling module to investigate the characterization of user's goals and behaviors in terms of energy consumption. Besides the wireless sensor networks, the User Profiling module acquires data also from a questionnaire which mainly concerns four categories, i.e. characteristics of the residents, electrical appliances, attitudes towards energy and building structural information. Furthermore, based on the real-time information from the sensor network platform and the user profiling module, an embedded Resource and Consumption Controller will then adapt automatically for instance the regulation processes of energy consumption in a household locally for the users, so that the costs of all energy resources will not exceed the predetermined budget and be regulated in a user-preferred way. © 2011 IEEE.

  • 30.
    Frost, Anna
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Maher, Azaza
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Patterns and temporal resolution in commercial and industrial typical load profiles2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, 2684-2689 p.Article in journal (Refereed)
    Abstract [en]

    Load patterns often have a periodicity of a day, week and year, which can be taken advantage of when preprocessing load data before clustering. A typical load profile, which reflects the customer's load for a characteristic day, week or year, could be constructed to reduce the data to be processed during the clustering. Typical Daily Profiles (TDP) and Typical Weekly Profiles (TWP) are compared to see how the time resolution of data affects the clustering. Results show that the number of clusters affects the Davies-Bouldin Index and the Dunn Index more than the temporal resolution of data as well as if TDPs or TWPs are clustered. Further, clustering based on customers' TWP instead of TDP makes it easier to find customers which have equipment turned on during Saturdays. This could be of importance when clustering is used to improve forecasting, distribution planning or tariff design

  • 31.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of a Battery Train Using Dynamic Programming2015Conference paper (Other academic)
    Abstract [en]

    Electric propulsion system in trains has the highest efficiency compared to other propulsion systems (i.e. steam and diesel). Still, electric trains are not used on all the routes, due to the high setup and maintenance cost of the catenary system. Energy storage technologies and the battery driven trains however, make it possible to have the electric trains on the non-electrified routes as well. High energy consumption of the electric trains, makes the energy management of such trains crucial to get the best use of the energy storage device. This paper suggests an algorithm for the optimal control of the catenary free operation of an electric train equipped with an onboard energy storage device. The algorithm is based on the discrete dynamic programming and Bellman’s backward approach. The objective function is to minimize the energy consumption, i.e. having the maximum battery level left at the end of the trip. The constraints are the trip time, battery capacity, local speed limits and limitations on the traction motor. Time is the independent variable and distance, velocity and battery level are the state variables. All of the four variables are discretized which results in some inaccuracy in the calculations, which is discussed in the paper. The train model and the algorithm are based on the equations of motion which makes the model adjustable for all sorts of electric trains and energy storage devices. Moreover, any type of electrical constraints such as the ones regarding the voltage output of the energy storage device or the power output can be enforced easily, due to the nature of the dynamic programming. 

  • 32.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    SICS - swedish institute of computer science, Sweden.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    AN ALGORITHM FOR OPTIMAL CONTROL OF AN ELECTRIC MULTIPLE UNIT2014In: Proceedings from The 55th Conference on Simulation and Modelling (SIMS 55),21-22 October, 2014. Aalborg, Denmark, Linköping: Linköping University Electronic Press, 2014Conference paper (Refereed)
    Abstract [en]

    This paper offers a solution for the optimal EMU train (Electric Multiple Unit) operation with the aim of minimizing the energy consumption. EMU is an electric train with traction motors in more than one carriage. The algorithm is based on dynamic programming and the Hamilton-Jacobi-Bellman equation. To model the train, real data has been used, which was provided by experts from Bombardier Transportation Västerås. To evaluate the model, some experiments have been done on the energy saving in exchange for the increase in the trip time. Moreover a simple accuracy factor is introduced to evaluate the accuracy of the model. The final goal is to use this approach as a base for a driver advisory system, therefore it is important to have the amount of calculations as minimum as possible. The paper also includes the studies done on the calculation time. The solution can be used for driverless trains as well as normal trains. It should be mentioned that this paper is a part of a research which is still in progress and the final model will also be used by Bombardier Transportation Västerås as an evaluation tool for the propulsions systems and trains.

  • 33.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    SICS Swedish ICT, Sweden.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of an EMU Using Dynamic Programming2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, 1913-1919 p.Article in journal (Refereed)
    Abstract [en]

    A model is developed for minimizing the energy consumption of an electric multiple unit through optimized driving style, based on Hamilton-Jacobi-Bellman equation and Bellman's backward approach. Included are the speed limits, track profile (elevations), different driving modes and the train load. This paper includes aspects like the power loss in the auxiliary systems, time management, validation of the model regarding energy calculations and a study on discretization and the accuracy of the model. The model will be used as a base for a new driver advisory system. 

  • 34.
    Ghaviha, Nima
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Bohlin, Markus
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Optimal Control of an EMU Using Dynamic Programming and Tractive Effort as the Control Variable2015In: Proceedings of the 56th SIMS, Linköping University Electronic Press, Linköpings universitet, 2015, 377-382 p.Conference paper (Refereed)
    Abstract [en]

    Problem of optimal train control with the aim of minimizing energy consumption is one of the old optimal control problems. During last decades different solutions have been suggested based on different optimization techniques, each including a certain number of constraints or different train configurations, one being the control on the tractive effort available from traction motor. The problem is previously solved using dynamic programming for trains with continuous tractive effort, in which velocity was assumed to be the control variable. The paper at hand presents a solution based on dynamic programming for solving the problem for trains with discrete tractive effort. In this approach, tractive effort is assumed to be the control variable. Moreover a short comparison is made between two approaches regarding accuracy and ease of application in a driver advisory system.

  • 35.
    Javed, F.
    et al.
    LUMS School of Science and Engineering, Lahore, Pakistan.
    Arshad, N.
    LUMS School of Science and Engineering, Lahore, Pakistan.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    An adaptive optimization model for power conservation in the smart grid2010In: Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics, 2010, 2010, 1563-1570 p.Conference paper (Refereed)
    Abstract [en]

    Dynamically adaptive systems (DAS) such as smart grids, cloud computing applications, sensor networks and P2P networks tend to change their structure at runtime. T herefore, design-time modeling for such systems are sometimes not enough to incorporate self-* properties. To this end, we have developed a dynamic mathematical modeling framework for runtime optimizations for DAS. In this paper, we describe how our system engineers a linear programming model by using a smart-grid application for power distribution as a case-study. At runtime whenever an optimization is desired this modeling framework captures the state of the system, converts it into an appropriate linear programming model, plan the changes using mathematical manipulations and apply the changes to the actual system. Our results show that this framework is able to capture accurate runtime models of large power systems and is able to adapt itself with the change in the size or structure of the system.

  • 36.
    Javed, F.
    et al.
    School of Science and Engineering, Lahore, Pakistan.
    Arshad, N.
    School of Science and Engineering, Lahore, Pakistan.
    Wallin, Fredrik
    Mälardalen University, Department of Public Technology.
    Vassileva, Iana
    Mälardalen University, Department of Public Technology.
    Dahlquist, Erik
    Mälardalen University, Department of Public Technology.
    Engineering optimization models at runtime for dynamically adaptive systems2010In: Proceedings of the IEEE International Conference on Engineering of Complex Computer Systems, ICECCS, 2010, 253-254 p.Conference paper (Refereed)
    Abstract [en]

    Dynamically adaptive systems (DAS), such as smart grids, cloud computing applications, sensor networks and P2P networks tend to change their structure at runtime. Therefore, design-time modeling for such systems are sometimes not enough for self-management. To this end, we have developed a dynamic mathematical modeling framework for runtime modeling for DAS. In this paper, we describe how our system engineers a linear programming model for self-optimization by using a smart-grid application for power distribution as a case-study. At runtime whenever, an optimization is desired this modeling framework captures the state of the system, converts it into an appropriate linear programming model, plan the changes using mathematical manipulations and apply the changes to the actual system. Our initial simulation results show that this framework is able to capture accurate runtime models of large power systems and is able to adapt itself with the change in the size or structure of the system by constructing a succinct model which is faster and more efficient than a design time model.

  • 37.
    Javed, Fahad
    et al.
    LUMS Sch Sci & Engn, Dept Comp Sci, Lahore, Pakistan.
    Arshad, Naveed
    LUMS Sch Sci & Engn, Dept Comp Sci, Lahore, Pakistan .
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Vassileva, Iana
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Forecasting for demand response in smart grids: An analysis on use of anthropologic and structural data and short term multiple loads forecasting2012In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 96, 150-160 p.Article in journal (Refereed)
    Abstract [en]

    The electric grid is changing. With the smart grid the demand response (DR) programs will hopefully make the grid more resilient and cost efficient. However, a scheme where consumers can directly participate in demand management requires new efforts for forecasting the electric loads of individual consumers. In this paper we try to find answers to two main questions for forecasting loads for individual consumers: First, can current short term load forecasting (STLF) models work efficiently for forecasting individual households? Second, do the anthropologic and structural variables enhance the forecasting accuracy of individual consumer loads? Our analysis show that a single multi-dimensional model forecasting for all houses using anthropologic and structural data variables is more efficient than a forecast based on traditional global measures. We have provided an extensive empirical evidence to support our claims.

  • 38.
    Klintenberg, Patrik
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Azimoh, Chukwuma Leonard
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Successful technology transfer: What does it take?2014In: Applied Energy, ISSN 0306-2619, Vol. 130, 807813- p.Article in journal (Refereed)
    Abstract [en]

    Technology transfer from developed to developing countries is often problematic. Insufficient resources for operation and maintenance after project finalization are common challenges. Findings from assessments of two projects in rural Botswana and Namibia where different renewable energy technologies were introduced to improve access to electricity are presented. In Tsumkwe, a Namibian off-grid settlement with about 4000 inhabitants, a large solar-diesel hybrid system has been constructed. A smaller system using photovoltaic and biogas is piloted in the off-grid settlement Sekhutlane in Botswana. In Sekhutlane beneficiaries' ability to pay for services is addressed by supporting local entrepreneurs to establish electricity-based businesses. Functionality of installations was inspected and semi-structured interviews were held with key stakeholders. In Tsumkwe local service providers were unprepared to take charge of operations and maintenance after completion of the project and users have difficulties paying for the services. Too strong focus on technology and insufficient efforts made to involve local institutions and beneficiaries throughout the project are main causes. The promotion of local entrepreneurship in Sekhutlane has resulted in 17 local businesses being established, likely to strengthen the cash economy and improved ability to pay for services, and thereby contributing financial resources towards operation and maintenance of systems. © 2014 Elsevier Ltd.

  • 39.
    Kovala, Tommy
    et al.
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Hallin, Anette
    Mälardalen University, School of Business, Society and Engineering, Industrial Economics and Organisation.
    Factors influencing industrial excess heat collaborations2016In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 88, 595-599 p.Article in journal (Refereed)
    Abstract [en]

    In Sweden there is a potential to double the amount of industrial excess heat from todays 5 TWh that is delivered into district heating networks. This paper investigates factors that are influencing industrial excess heat collaborations. The paper presents result from qualitative interviews as well as answers through a more quantitative web based survey which has been sent out to stakeholders in existing Swedish industrial excess heat collaborations. This work provides new evidence on that economic motivations are the most common driver for starting up a collaboration, but well in place factors like transparency as well as investment sharing between the partners becomes important for a long-term successful collaboration.

  • 40.
    Li, Hailong
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Sun, Qie
    Shandong University, China.
    Zhang, Qi
    China University of Petroleum, China.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    A review of the pricing mechanisms for district heating systems2015In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 42, 56-65 p.Article in journal (Refereed)
    Abstract [en]

    Heating represents the largest proportion of energy use as supplied to consumers across all end energy uses. Therefore, there is huge potential for energy savings in the heating sector in order to reduce the emission of CO2. District heating (DH) has been considered an efficient, environmentally friendly and cost-effective method for heating in buildings, and is playing an important role in the mitigation of climate change. In the interest of fairness and in the highly competitive market the DH companies operate, there is a strong need to develop a novel heat pricing mechanism in order to promote sustainable development of DH systems. In this paper, existing methods and models regarding heat pricing have been reviewed. The features of different pricing mechanisms have been analysed, including advantages and disadvantages. Insights into developing an advanced pricing mechanism for DH systems have been offered.

  • 41.
    Lundström, Lukas
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Eskilstuna Energy and Envirorment, Eskilstuna; Eskilstuna kommunfastigheter, Eskilstuna .
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Helgesson, Jan
    Eskilstuna kommunfastigheter, Eskilstuna .
    Björklund, Ulf
    Eskilstuna Energy and Environment, Eskilstuna .
    Impact on carbon dioxide emissions from energy conservation within Swedish district heating networks2014In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, 2132-2136 p.Article in journal (Refereed)
    Abstract [en]

    The 100 largest Swedish district heating (DH)-networks were studied on how DH conservation measures impacts CO2-emission rates taking both direct and indirect (i.e. displaced electricity) emissions into account, applying six different methods for the indirect emissions assessment. When the marginal electricity approach is applied on low CO2-emitting DH-networks with a high share of cogenerated electricity, it resulted in assessments that imply that DH conservation leads to higher CO2 emissions. This was not the case with the efficiency method.

  • 42.
    Lundström, Lukas
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Heat demand profiles of energy conservation measures in buildings and their impact on a district heating system2016In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 161, 290-299 p.Article in journal (Refereed)
    Abstract [en]

    This study highlights the forthcoming problem with diminishing environmental benefits from heat demand reducing energy conservation measures (ECM) of buildings within district heating systems (DHS), as the supply side is becoming "greener" and more primary energy efficient. In this study heat demand profiles and annual electricity-to-heat factors of ECMs in buildings are computed and their impact on system efficiency and greenhouse gas emissions of a Swedish biomass fuelled and combined heat and power utilising DHS are assessed. A weather normalising method for the DHS heat load is developed, combining segmented multivariable linear regressions with typical meteorological year weather data to enable the DHS model and the buildings model to work under the same weather conditions. Improving the buildings' envelope insulation level and thereby levelling out the DHS heat load curve reduces greenhouse gas emissions and improves primary energy efficiency. Reducing household electricity use proves to be highly beneficial, partly because it increases heat demand, allowing for more cogeneration of electricity. However the other ECMs considered may cause increased greenhouse gas emissions, mainly because of their adverse impact on the cogeneration of electricity. If biomass fuels are considered as residuals, and thus assigned low primary energy factors, primary energy efficiency decreases when implementing ECMs that lower heat demand.

  • 43.
    Lyu, H.
    et al.
    China University of Petroleum, Beijing, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Xv, B.
    China University of Petroleum, Beijing, China.
    Research on Chinese Solar Photovoltaic Development Based on Green-trading Mechanisms in Power System by Using a System Dynamics Model2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, 3960-3965 p.Article in journal (Refereed)
    Abstract [en]

    China power year book in 2014 set the target of 300GW of PV installed capacity in 2030. Solar photovoltaic (PV) has shown a significant rise because of green-trading mechanisms. This study focuses on feed in tariff (FIT) and renewable portfolio standard (RPS). The objective of these two policies is attracting the public to invest in and to use solar PV system. Based on the experience of Germany about FIT, this paper aims to evaluate the FIT and RPS policies in promoting installed PV capacity in China. A system dynamics (SD) model of PV system that includes FIT, RPS, PV cost, and installed capacity is built in this study. By using Vensim-DSS software, this paper assesses the effect of different combinations of policies on installed capacity of PV and emission reduction, and finds optimal policy combination. The results show that all four scenarios can reach the target of 300 GW in 2030. The government cost of optimal scenario will be 251 billion RMB less than the scenario of historical trend. 

  • 44.
    Maher, Azaza
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Finite State Machine Household's Appliances Models for Non-intrusive Energy Estimation2017In: Energy Procedia, Elsevier Ltd , 2017, 2157-2162 p.Conference paper (Refereed)
    Abstract [en]

    Non-intrusive loads monitoring NILM is a set of algorithms that aims to leverage smart meter data by extracting more useful information from the smart meter data. NILM involves disaggregation of individual household loads in term of their individual energy consumption. It is considered as low cost alternative to better understand the electrical network and reduce complexity of the management operations. It offers to households monitoring and control possibilities to their everyday energy consumption. This paper contributes toward non-intrusive energy estimation of household's loads through data-driven appliances modelling approach based on finite state machine models that mimic the real operations cycle. First, the models are built based on features extractions and events clustering via dynamic fuzzy clustering. The resulting clusters are further de-noised and processed to reveal accurate appliances operations states. Then finite state machine models are created using transition probability matrix and an optimization approach to extract the operation cycle that best describe real appliance operations. The evaluation of the framework was performed using two public datasets showing its performance to learn appliances models and energy estimation with an average error of 5% to 22%. © 2017 The Authors.

  • 45.
    Maher, Azaza
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Multi objective particle swarm optimization of hybrid micro-grid system: A case study in Sweden2017In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 123, 108-118 p.Article in journal (Refereed)
    Abstract [en]

    Distributed energy resources DERs are small scale energy system which could provide local supply when placed at customers' premises. They aggregate multiple local and diffuse production installations, consumer facilities, storage facilities and monitoring tools and demand management. The main challenges when assessing the performance of an off-grid hybrid micro-grid system HMGS are the reliability of the system, the cost of electricity production and the operation environmental impact. Hence the tradeoff between three conflicting objectives makes the design of an optimal HMGS seen as a multi-objective optimization task. In this paper, we consider the optimization and the assessment of a HMGS in different Swedish cities to point out the potential of each location for HMGS investment. The HMGS consists of photovoltaic panels, wind turbines, diesel generator and battery storage. The HMGS model was simulated under one-year weather conditions data. A multi objective particle swarm optimization is used to find the optimal system configuration and the optimal component size for each location. An energy management system is applied to manage the operation of the different component of the system when feeding the load. The techno economics analysis shows the potential of HMGS in the Swedish rural development. (C) 2017 Elsevier Ltd. All rights reserved.

  • 46.
    Maher, Azaza
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Wallin, Fredrik
    Mälardalen University, School of Innovation, Design and Engineering, Embedded Systems.
    Supervised Household’s Loads Pattern Recognition2016In: 2016 IEEE Electrical Power and Energy Conference, EPEC 2016 / [ed] IEEE, 2016, 7771718Conference paper (Refereed)
    Abstract [en]

    The deployment of smart meters is a promising innovation that comes to enhance the energy efficiency measures in the smart grid. The smart meter enables distributors to better understand the electrical network and reduce complexity of the management operations. It offers to households monitoring and control possibilities to their everyday energy consumption through the distribution of detailed information on household consumption and its evolution. This involves disaggregation of individual household loads in term of their individual energy consumption known as Non intrusive loads monitoring. In this paper, we present a supervised NILM approach based on dynamic fuzzy c-means events clustering and KNN label matching. First, a filtering method is involved to enhance the edge/events detection step. Then we perform a dynamic Fuzzy c-means clustering procedures to build appliances signature data based on active and reactive power measurements taking into account the time of day usage. The data base is further refined to map potential clusters centers that best identify the different appliances. A performance evaluation of the proposed approach is conducted showing a recognition rate over 90% for high consumption loads and promising results for low consumption loads.

  • 47.
    Mamchych, Tetyana
    et al.
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics. Eastern European University, Lutsk, Ukraine.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Looking for Patterns in Residential Electricity Consumption2014In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 61, 1768-1771 p.Article in journal (Refereed)
    Abstract [en]

    Residential electricity consumption is an important part of general energy use. Its detailed investigation, however, requires rich empirical data, here the data of Swedish households. The individual consumption is a time series of readings at certain time intervals (hourly, every ten minutes, or every minute, say). Series exhibit patterns, in terms of which they may be compared, and it is desirable to model similarity. Classical statistical methods (correlation, factor, and cluster analyses) are presently used for this purpose; they have the advantage of being more explicit than the techniques of adaptive data analysis that may recently have become excessively popular. The present work is methodological, preceding any massive statistical analyses. Factor analysis allowed describing individual styles in terms of time intervals (during a day) of maximal variability. Cluster analysis was used for finding groups of days with similar patterns; the obtained clusters can help interpreting the results of other methods. Comparing two households requires comparing two sets of time series; correlation analysis quantified the similarity between them.

  • 48.
    Mamchych-Mitkalik, Tetyana
    et al.
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics. Eastern European Lesya Ukrainka Natl Univ, Lutsk, Ukraine.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Stability of patterns in residential electricity consumption2015In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, 2738-2744 p.Article in journal (Refereed)
    Abstract [en]

    The problems of predicting and of pricing residential electricity consumption are closely related to the technical problem of the term of stability of pattern. Indeed, the general meaning of the word "pattern" would normally imply an assumption of stability, and here we attempt quantifying this notion: from being specific to some measurement data, to being characteristic of a household. Our working objective is to assess the stability of electricity consumption by selected Swedish households, and our main statistical instrument is a specially-devised coefficient of auto-similarity. Households are represented by sequences of readings of energy consumption, spaced at equal time intervals. (C) 2015 Published by Elsevier Ltd.

  • 49.
    Ni, Ying
    et al.
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Engström, Christopher
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Malyarenko, Anatoliy
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Building-type classification based on measurements of energy consumption data2014In: SMTDA 2014 Proceedings / [ed] H. Skiadas (Ed), ISAST: International Society for the Advancement of Science and Technology , 2014, 519-529 p.Conference paper (Refereed)
    Abstract [en]

    In this paper we apply data-mining techniques to a classication problemon actual electricity consumption data from 350 Swedish households. Morespecically we use measurements of hourly electricity consumption during one monthand t classication models to the given data. The goal is to classify and later predict whether the building type of a specic household is an apartmentor a detached house. This classication/prediction problem becomes important ifone has a consumption time series for a household with unknown building type. Tocharacterise each household, we compute from the data some selected statistical attributesand also the load prole throughout the day for that household. The most important task here is to select a good representative set of feature variables, whichis solved by ranking the variable importance using technique of random forest. Wethen classify the data using classication tree method and linear discriminant analysis.The predictive power of the chosen classication models is plausible.

  • 50.
    Ni, Ying
    et al.
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Engström, Christopher
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Malyarenko, Anatoliy
    Mälardalen University, School of Education, Culture and Communication, Educational Sciences and Mathematics.
    Wallin, Fredrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Investigating the added values of high frequency energy consumption data using data mining techniques2014In: AIP Conference Proceedings 1637 (2014): Volume number: 1637; Published: 10 december 2014 / [ed] Seenith Sivasundaram, AIP Publishing , 2014, 734-743 p.Conference paper (Refereed)
    Abstract [en]

    In this paper we apply data-mining techniques to customer classification and clustering tasks on actual electricity consumption data from 350 Swedish households. For the classification task we classify households into different categories based on some statistical attributes of their energy consumption measurements. For the clustering task, we use average daily load diagrams to partition electricity-consuming households into distinct groups. The data contains electricity consumption measurements on each 10-minute time interval for each light source and electrical appliance. We perform the classification and clustering tasks using four variants of processeddata sets corresponding to the 10-minute total electricity consumption aggregated from all electrical sources, the hourly total consumption aggregated over all 10-minute intervals during that clock hour, the total consumption over each four-hour intervals and finally the daily total consumption. The goal is to see if there are any differences in using data sets of various frequency levels. We present the comparison results and investigate the added value of the high-frequency measurements, for example 10-minute measurements, in terms of its influence on customer clustering and classification.

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