SCCER JA-RED - Report on the performance of the implemented solutions with guidelines for subsequent implementation - D1.2.4

The foreseen important increase of the penetration of distributed renewable energies technologies into the electricity distribution grid is expected to lead to some major challenges. On the one hand, a large and synchronous production could lead in certain time periods to a surplus of production, exceeding the consumption needs and resulting in a zero or negative market value of electricity that may deter any incentive to further invest in certain sources of renewable energy. This production surplus is also expected to lead to grid congestion, transformer overloading and overvoltage situations that will critically affect grid operation. Yet, if the renewable energies technologies, storage devices, and electrified loads are exploited through coordinated control mechanisms they could also offer new opportunities for stakeholders. The JA-RED partners have therefore developed methods to evaluate the long-term implementation of decentralized solutions that could be massively deployed to decarbonize and denuclearize the Swiss energy mix, while providing economic opportunities for all stakeholders. This report takes a deeper look at the implemented decentralized energy solutions integrating heat pumps, heat storage, batteries and solar panels considering shading effect, not only on roofs, but also on facades of the district which indeed host 70% of the available PV area and near half of the generation potential. Achieving self-sufficiency at district scale is challenging: it can be achieved by covering approximately 42% to 100% of the available surface when the round trip efficiency decreases from 100% to 50%. The results underlined the importance of storage for achieving self-sufficiency: even with 100% round trip efficiency for the storage, very large capacities are required. Moreover, the grid revenues generated by the difference between retail and feed-in prices are not sufficient to pay for the storage required to make the district self-sufficient, suggesting that public funding would be crucial for supporting these developments. This arise with relatively low installed PV capacity (PV area / heated area = 0.2), when storage starts to be seasonal rather than daily. However, energy demand reduction through renovation would allow to reach self-sufficiency with half of the PV and storage capacity required for the actual building stock, and the deployment of additional long-term storage capacity could be implemented together with the development of the next 5th generation of district heating and cooling systems, realizing sector coupling with power to gas (P2G) and electro-thermal energy storage (ETES).