I've been wondering why AC units for buildings don't come in solar cell combi packages, where if it's hot, it's sunny, so the ac can be powered by the sun, ideally making it a zero sum calculation.
Because it is not cost effective. Fossil fuel is still cheaper. Unless solar prices ( installation- panel, batteries) comes down or subsidised to match those existing prices, it will still take some time .
Because the amount of solar required to power an air conditioner is significantly larger than the air conditioner itself and often you need more solar than you have roof space for buildings 2 stories and greater. (i.e. the total amount of solar you can fit on the roof of a 4 story building will likely not be sufficient to run the air conditioner required to cool that building.)
