People (nuclear advocates usually), like to pretend that the only way to deal with this is an unrealistic number of expensive lithium batteries or fossil fuels but there is also:
* Smart meters that charge cars/turn on heat pump storage when electricity is plentiful. Already being done. German aluminum smelting (heavy electricity user) is dialed up and down depending on live electricity prices.
* Pumped storage. Coire glass will built soon in the UK - pumping out a max of 1.5GW, snowy 2 in Australia will store 350GWh - at the dirt cheap price of $6 billion. 90% efficient. Published studies confirm that, unlike for dams, the geography for this is very plentiful (contrary to nuclear lobby propaganda which routinely and dishonestly argues the exact opposite).
* Hydrogen/windgas - only about 50% efficient round trip but it's easy to store hundreds of GWhs for months, so will be useful to create seasonal storage when, one day (god willing) we get to the point where overbuilt wind and solar manages to supply 100% of current demand and large pumped storage/battery installations are full and we want seasonal storage for the unshiftable demand during the odd windless and dark weeks.
* Smart meters that charge cars/turn on heat pump storage when electricity is plentiful. Already being done. German aluminum smelting (heavy electricity user) is dialed up and down depending on live electricity prices.
* Pumped storage. Coire glass will built soon in the UK - pumping out a max of 1.5GW, snowy 2 in Australia will store 350GWh - at the dirt cheap price of $6 billion. 90% efficient. Published studies confirm that, unlike for dams, the geography for this is very plentiful (contrary to nuclear lobby propaganda which routinely and dishonestly argues the exact opposite).
* Hydrogen/windgas - only about 50% efficient round trip but it's easy to store hundreds of GWhs for months, so will be useful to create seasonal storage when, one day (god willing) we get to the point where overbuilt wind and solar manages to supply 100% of current demand and large pumped storage/battery installations are full and we want seasonal storage for the unshiftable demand during the odd windless and dark weeks.