*4.3. Potential Solutions beyond Solar PV*

The supply and demand mismatch in winter and summer is one of the major roadblocks in the total phase-out of coal power plants through solar energy. Diurnal storage will be enough to solve the mismatch during summer, but seasonal storage or seasonal generation will be necessary for winter. Since there is still enough excess energy during peak solar production in summer, storage is the straightforward solution once these options become economically feasible. However, since there is less solar energy in winter, there is not enough excess solar energy for diurnal storage to work, which opens an opportunity for seasonal technology. Seasonal storage in the form of power-to-gas (P2G) could store the excess solar in autumn for winter. Combined heat and power (CHP) plants could be operated at a higher capacity in winter if local water heating is established.
