[lapink]

Precooling is only viable if homes are really insulated and / or all the electricity comes from renewable as otherwise it will increase the overall energy used (as precooling is less efficient), which will increase CO2 emissions. In think the population also needs to “meet in the middle”, for instance by increasing the temperature of the AC by one degree in summer. This could get automated to offer a best effort service.

[pfdietz]

Of course precooling is less efficient. But if there are large swings in price that can more than make up for it. And if daytime solar is replacing evening peak natural gas the CO2 emissions are reduced also.