And it only gets worse the more households transition to heatpumps, because the consumption in winter is so lopsided. For example, I heat my home with a heatpump, and I have 10 kWp of solar arrays on my roof. In the last week of July, we consumed 84 kWh and generated 230 kWh (273 %). In the last week of November, we consumed 341 khW and generated 40 kWh (11 %). This means we'd need roughly 10 times as much PV area to match demand (10 roofs?), and huge batteries because most of that consumption is in the evening, at night, and in the morning.
Of course, utility-scale and residential solar behave a bit differently, and it becomes more complicated if wind is factored in. But it shows that you can't just overprovision PV a little to fix the main problem of solar power: that it is most abundant in summer, and most in demand in winter.
