Investigation of a balanced Swedish energy system in 2045 : Analysis of technical specifications for flexibility needed in a future Swedish intermittent electricity system.

Abstract: As part of Sweden's goal of zero carbon dioxide emissions, renewable energy will play an increasingly important role in the future. A major change in the electrification of industries and the transport sector will lead to an ever-increasing need for electricity production. Modern electricity production in the form of solar energy and wind power brings new challenges for the Swedish electricity system. Electricity production and consumption must always be the same momentarily. This is so that the frequency can be controlled and kept at 50 Hz. As the Swedish electricity system is designed according to a frequency of 50 Hz, there are major consequences, such as power outages, if the frequency deviates from this for a longer period of time. The Swedish Transmission System Operator (TSO) is responsible for balancing the production and consumption to be on the same level at all time. To do so with weather dependent intermittent power sources that lacks natural inertia needs additional and external balancing assets. This report investigates the technical specifications needed for a balanced future Swedish energy system. This rapid regulation is a problem in today's system, but in this report it is assumed that the rapid regulation is not a problem in a future system, instead it is examined how large the need for regulation is when consumption is significantly higher than today, and when this increased consumption is covered by weather-dependent renewable energy. In this report, six different scenarios are modeled on how a future electricity system could be designed. These scenarios are based on Svenska Kraftnät's long-term market analysis, where different scenarios are based on different degrees of electrification and scaling of the respective producer. The different scenarios are modeled so that increased consumption is met with different scaling by the respective electricity producer. The production profile and the consumption profile are then compared in order to find how much the two deviates and for how long. This in order to find the technical specifications needed for external balancing assets in the different system designs. The results of the modeling show that what will be decisive in the future is the extent to which there is flexibility in both production and consumption. It shows that it will not be sustainable to only expand production, but this must also be met by consumption. This consumption can be energy storage or export, but as both storage and export are limited, there must also be an opportunity to control surplus production. The result shows how much flexibility is required for each specific future scenario, i.e. what maximum capacity must exist, as well as how sustainable this resource must be for the system to be stable. In the report there is one scenario were the system is optimized according to available balancing reserve, adjusted consumption profile and a large increase in consumption and weather dependent power sources. This leads to the need for a flexibility with a peak hour demand of 0,3 GW; duration time of 5 hours and a total capacity of 1,5 GWh.