Potential till flexibilitet och energilagring : modellering av det framtida bostadsområdet Tarv Västra

Sammanfattning: Knivsta municipality is expanding with new residential areas. Meanwhile, the housing sector already accounts for 40 % of Sweden’s total energy use. To ensure energy security in future residential areas and to reduce instability in the power system due to increased intermittent energy production, the need and potential for energy storage and flexibility solutions must be investigated. Implementing these solutions in residential areas will lead to increased self-sufficiency and hence relieve surrounding power system, whereon Tarv Västra, a future community planned in Knivsta, intends to implement these solutions. The aim of this project was to examine how local electricity and heat production, in combination with flexibility and storage, could contribute to increased local energy independence in Tarv Västra and to balance the surrounding power system. The system solutions implemented are borehole thermal storage, batteries and hydrogen for energy storage, as well as vehicle-to-grid and demand flexibility as flexibility solutions. To assess the requirement for energy storage and flexibility in the residential area, it was essential to analyze both energy demand and production. Modelling of the chosen system solutions could then be conducted on an hourly basis using previous academic works and assumptions. To nuance the results, the created model was simulated with 0 %, 20 % and 40 % base load of electricity from the power grid. The created model of energy solutions in Tarv Västra resulted in a high potential for energy storage and flexibility to reach a higher degree of self-sufficiency as well as relief of the surrounding grid. The degree of self-sufficiency increased with less percentage of base load from the local power grid (60 %, 64 %, 70 % with 40 %, 20 %, 0 % of baseload), unlike the degree of peak coverage which increased with greater percentage of base load (78 %, 86 %, 100 % with 0 %, 20 %, 40 % of baseload). The combination of borehole thermal storage, batteries and hydrogen satisfied the entire heating requirement and a major part of the electricity requirement. Implementation of vehicle-to-grid and demand flexibility relieved the power system regarding to the number of extracted power peaks.