> Arguments for all other forms of renewables at scale right now seem to depend on having/maintaining fossil fuel power generation just to satisfy daily demand reliably, so you end up with two sets of power generation infrastructure designed to meet peak capacity (so effectively double capacity of what’s needed), which is extraordinarily expensive.
I'm by no means an expert on this but I've been trying to learn more about it recently. From what I gather the end-state can be 100% renewables in different ways:
1) Have enough hydro that can be turned into pumped storage that a complete grid mix can be done with just hydro+solar+wind with very little overbuild. Portugal has very good conditions for this and back of the envelope calculations tell me it's possible with just 15% overbuild. All of the extra is solar which is very cheap[1]. With a better interconnected European grid it may be possible to do that across the whole continent.
2) Overbuild solar and wind by a large amount since they're so cheap, supplement that with some expensive batteries, and allow energy prices to go to zero and even negative at times to see if anyone has a use for the excess energy. We're talking something like 3-5x overbuild and then having so much excess energy that you start disrupting other fossil fuel usage[2].
If you have a seasonal storage breakthrough you're back at 1) with just another technology in place of hydro. Financing hydrogen generation seems to me like picking winners within 2). Both scenarios can be supplemented if shaping demand can be made at scale. Things like heating buildings and charging EVs can be shifted a few hours during the day without much inconvenience and possibly allow shaving off some important peaks.
Most of this discussion would be avoided if we just put a steadily increasing price on carbon, remove all other subsidies, and let the market shake things out.
[1] https://docs.google.com/spreadsheets/d/1UTUjhrBF04MP38b4WlQx...
[2] https://static1.squarespace.com/static/585c3439be65942f022bb...
