I would also add that heat insulation is grossly underrated. With modern heat insulation solutions like wood or hemp concrete, mineral wool one can decrease the

I would also add that heat insulation is grossly underrated. With modern heat insulation solutions like wood or hemp concrete, mineral wool one can decrease the heating / cooling need by 60-80%. This can be combined with solar panels. In practice, this means we have ~10 USD heating / cooling cost per month for a medium size house in Central Europe. Initial cost is not trivial though. Same goes for other usage of electricity, for example lighting. Using LED lights reduce the energy need by a large percentage. The best energy optimisation is to reduce the amount of energy needed to be produced. Once you have that it becomes easier even with current technology to have a battery that can buffer your electricity,