Demand shaping - Germany pioneered this by dialing aluminum smelter usage up and down in the early days. They didn't talk about it much, I think because it functioned as a kind of hidden subsidy and they didn't want to attract undue attention. There's LOTS of scope for stuff like heaters and vehicles batteries to use electricity when it's plentiful and cheap and turn it off when it's not. The UK has a special electricity tariff for this already which is very popular with electric car drivers. Demand shaping is, relative to storage, really cheap and usually gets forgotten about in skeptical renewable energy models.

Pumped storage and batteries for short term energy storage - hours to weeks. Australia is already building one pumped storage battery which should provide them with roughly 350GWh - roughly half of the short term storage they'd need if they had a 100% solar and wind based grid. With one plant. You can't do this in, e.g. Florida but the geography to build this is more than plentiful enough in most of the world (this topic is pretty well settled: https://www.nature.com/articles/s41467-020-14555-y but for some reason people keep disputing it).

Hydrogen for seasonal storage - for weeks when the wind doesn't blow and the sun doesn't shine. Roughly 2-3% of power will need to be stored this way on a 100% solar/wind grid. It's not efficient and expensive to generate hydrogen from electricity and then turn it back into electricity but still cheaper than generating and using nuclear power at the point of generation. It is cheap to store enormous amounts of power for long periods this way though.