| The whole "what about at night?!" line has been trotted incessantly out here, slashdot, hackaday, reddit, etc like people in the utility industry aren't aware. A huge amount of electrical load happens during the day that doesn't happen in the dead of the night, which is why many utilities offer nighttime cheaper rates. That hasn't stopped utilities from deploying wind and solar for 40% of their new generation over the last year or two, while shutting down coal plants left and right. For half a decade it's been considered settled fact that solar and wind are cheapest and the way forward. So, maybe this isn't as big a deal as you think it is. Attention long ago shifted toward planning the grid to accommodate that, and also on grid-scale storage projects. Pumped hydro has been used extensively in the UK for decades because every time the BBC finished a program, everyone watching TV would fire up their electric kettle at the same time. There are several pumped hydro installations in Canada and the US as well. Most EVs can schedule charging cycles and numerous utilities provide special rates for customers who agree to some level of utility control on their charging similar to how utilities provide discounts to people who let them tweak their AC thermostat; you can still override it, in most cases. In Australia, going back several decades, there was a grid load reduction signal system that worked by generating a harmonic that load reduction switches would look for. An increasing number of EVs are set up to be able to backfeed power into the grid, and the idea is that they could do so on request from the utility. Lots of utilities offer off-peak billing incentives. Imagine a world where your fridge does most of its cooling during the day, and "rides" through the night, etc. EV charging stations are starting to come with their own local battery systems because DC fast charging, particularly at 800V, is enough power that it can be difficult to get enough electrical service and in some locations the station sits unused for a fair period of time. Add in the fact that lithium ion battery prices continue to plunge following expected rules about production costs, as well as other technologies maturing; there's an iron salt based flow battery that looks really promising, made of very cheap and extremely prevalent materials (salt, iron, and water mostly) and scales fairly well. |
Conspicuously absent in this incomplete story is the fact that so much of the coal has been replaced by natural gas, which doesn't have the giant unreliability downside of solar and wind. You can get away with >=~40% of your energy generated by solar/wind on every single day of the year with no interruption. Bump that up to 80% and it'll take a long time and a lot of money to accomplish that without sacrificing reliability.
But why? Just use nuclear for the other half. The goal is not "renewable energy ASAP". The goal is "minimize fossil fuel usage ASAP".