@claralistensprechen3rd @Gustodon@mas.to I have extensive experience with both several designs of solar powered bicycles and with small FVE system, back-uped from grid, used only during 3 summer seasons (not during in winter). Even during summer, the solar bike struggles to recharge, when there are heavy clouds. 12V system without inverters would be better choice in winter, but generally, power generation is really limited during winter season. You could get some advantage with mixing with wind power, but it does not perform well for small scale systems (unlike FVE), and for most location it is not enough (but it is probably ok, if you live on the shores of North Sea..) I am all for solar and I promote it as much as possible: but we need long term storage, and the only publicly promoted alternative, hydrogen, is both expensive and inefficient (in terms of loses during charging and discharging of the storage). The most energy intense is heat generation (generally, something 50% of all energy consumption is heating). Heat pumps, exchangers, better insulation and waste heat recycling can help - but it means rethinking just everything about our civilization and way of life.