Comment by RGamma

I realize this doesn't really say anything about grid-level/national requirements, but at least in my situation 100% electric heating seems feasible.

Last year we used 7000kWh of natural gas (at 0.14€/kWh). Assuming 90% efficiency of our condensing boiler that's 6300kWh for heating water and air. We heat from ~November to ~February and use hot water all year round (though the cold water will vary by ~6 degC).

We have PV: 7.5kWp, 6kWh storage, electricity 2024: 6.3MWh generation, 2.1MWh usage at 80% autarky (100% from April to August, 90% March, Oktober, avg 50% November to February). 435kWh drawn from grid at 0.36€/kWh, 4.2MWh sent to grid at 0.075€/kWh

We can replace the boiler with a hot water heatpump that would be ~fully powered by our PV from ~March to ~Oktober. And for space heating we can use an air-air heatpump(s). We also have decent insulation and decentral ventilation with enthalpy exchanger.

Now the mystery is how much gas we waste in the non-heating period for hot water, and how little space heating we can get by with (small 60m^2 flat, kitchen, bedroom don't need heating) as well as the actual COP. My guess would be 3-4kWh of heating would be quite adequate plus whatever hot water will use.

We're currently looking for offers for getting rid of gas (and maybe central heating) completely. Wonder what calculation they'll come up with. Note that it doesn't need to be profitable at current prices as gas prices will rise, renewables will get cheaper, and you can still get 30-55% of subsidy.

I also consider getting rid of fossils completely a worthy struggle in itself as it reduces geopolitical dependence and increases resilience. But yeah, it's a multigenerational problem at this scale and scope, esp. considering all the other areas of overuse that need fixing.