Climate changes represent one of the greatest challenges of our time where global communities continue working together on research, observations, a better understanding of recent changes, and increased actions against environmental impacts. The global electricity demand constantly grows and is the most broadly used form of energy. Currently, the greatest amount of carbon dioxide emissions comes from generation of electrical energy, making a significant contribution to climate change. Besides the environmental concerns, another central issue is the aging of the electricity network, which struggles to fulfill the demands from the new infrastructure.

The concept of smart grids is a central part in managing current and future needs in the electricity sector and enables the possibility of developing and implementing new technologies, services and also increasing the choices and activities of the consumers. A smart grid is an intelligent modernized grid system that can balance the demand and supply of electricity, from an environmental, renewable and sustainable perspective.

The simulations made in this study are based on developed future energy scenarios on a city scale grid, which includes mass adoption of plug-in electric vehicle, large solar PV penetration at a residential level and demand response.

The early studies in our research demonstrate the significant role of renewing the existing traditional grid primarily due to the aging infrastructure and integration of new technologies. Traditionally, the electricity consumption has been the main controlling factor steering the production. In the future, the renewable energy production will steer the consumption, due to its unpredictability and intermittency. 

Sweden is an extreme example in case of weather conditions. The grid in Sweden is to be robust, as it has to handle the completely different conditions during the summer and winter, with its low-load-high-generation vs. high-load-low-generation features. Our thesis results indicate that a large amount of integrated electric vehicles affects the grid negatively by causing extreme high loads. Strategies for shifting and controlling of the electric vehicles charging showed to be of great importance in order to prevent extra peak increases. Even great amount of Photovoltaic resulted in negative impact on the grid, due to the overproduction that is to be handled by the network. Too much solar power requires high need of storage, in order to utilize the overproduction. Demand response proved to be a substantial part of the solution for the smart grid concept. 

In order to enable integrating of renewable energy sources and extra loads in form of electric vehicles, the grid is to undergo an evolution by gradually transforming into a more complex and intelligent grid. The grid evolution will take quite a long time, but after all a true smart grid will be able to adapt itself to varying environmental conditions.