Passive cooling and designing buildings to not overheat during summer in the first place is the way. And phoenix or Las Vegas shouldn't be much more than a gas station, they're unlivable hellholes without permanently pumping enormous amounts of energy in.
I have AC and heating and live in a very human-fiendly climate. I don't feel like a moron running it off my green power to heat and cool a very well insulated house beyond what the geothermal handles.
Oh, yeah, I looked at that. I can get a couple hundred watts of panels that will realistically generate about 300 watt hours of power on my balcony on the sunniest days, given that they won't be mounted at a very good angle. I can have it charge a battery pack that'll last a few years. Then I get about 90% efficiency if I'm lucky with the inverter. Even at $0.50/kWh, that's $0.15/day I'm saving or about $50/year if we just assume a cloudless year-round summer. That'll save me just enough money to buy a new battery when the first one gets old.
Solar power will get there one day. Its great for many purposes but its still not practical for most apartment dwellers.
Solar power works as a long term investment, but it's very expensive up front. The average "break even" point is around 10 years, and they'll last 25+
a couple hundred watts
Isn't really worth it. Realistic home systems are measured in several kilowatts.
And unless there's a pressing need for a battery like an off-grid setup: they're not worth it and you don't need one. The existing power grid is a "battery" you don't need to maintain -- any surplus power you back feed is power you can draw from it later for "free".
These won't even power a small portable AC, if you have a balcony and it's on the south side and you have enough m² to angle the panel halfway properly, you'll be lucky to generate 500 W.
That's only half the power draw of a small AC unit, and doesn't even get into the fact that in most places you cannot hook up a solar to your house without an approved inverter with appropriate safety features (otherwise you'd endanger the linemen in case of an outage). Where I live if you still have an old installation with net metering, you also pay a tax based on the inverter capacity (which is good because net metering is bullshit subsidies from the poor to the landowners).
PV energy is good, but apartments are not a reasonable use-case for it. Residential PV is inherently a tool for privileged house owners, and if PV is to help apartment dwellers it's through grid-scale renewables and dynamic pricing and/or smart grids that provide cheap power for A/C on sunny summer days.
You might not entirely cover the power consumption of an AC, but you can drastically lower the cost of using one by at least partially generating your own electricity.
As for the technical aspects I cannot argue at all, as I have no knowledge whatsoever in that regard.
It will take years before you make that money back on the investment though, depending on local taxation and electricity prices. And that's assuming that you have a decent enough orientation in the first place - some people live on the north side of their apartment block!
Always do the maths on PV for your situation, a 25 year positive ROI does not justify a purchase but a 10 year ROI might.
We need more A/C to survive climate change, but the solution can't be "put PV on balconies" because it's highly situational (not everyone has an adequately big south-facing balcony) and won't solve your problems if you could not afford the cooling bills in the first place (the only people who consider a 10 year ROI a good investment are the ones with capital to spare on home improvements). As with all personal renewable tech, it's a cost-saving tool for the well-off, not a structural solution to anything.
I think you grossly overestimate the power consumption of a heat pump (a split heat pump that is). On the hottest period of the year so far, ours used about 1,75kWh for a 40m² space.
One or 2 balcony mounted panels (given the right orientation, even with a suboptimal inclination) will easily deliver that much.
You are however right that most apartments can't profit much from solar power... The dynamic pricing however can make the cooling really cheap in the summer months. Just switch to non-dynamic pricing before the winter months to get the best year round price.
Two panels on the balcony of a 40m² studio? The 2x1m 400+ W ones? I did not even have a balcony when I lived in a studio lol. Anyways if you only require 1.75 kWh that's less than a euro of electricity even on fixed pricing. I think the real lesson here is that we haven't had summer yet this year so the AC barely turned on at all.
I just checked on Hubo, their cheapest portable A/C is 7000 BTU, i.e. 2 kW. That means if you had to use it at full tilt for an hour (not exactly an outlandish scenario in the previous years' summers), you'd use more electricity in that hour than you've had all year this year.
That's fucking nuts; the only time my power bill gets anywhere close to being that high is for three hours a day in June and July (34¢/kwh). For most of the year it's only 9¢/kwh.
Don't know how other countries do it, but in the US the home energy sector is highly regulated. Probably one of the only things we do right; but we soon as lawmakers try to propose similar regulations to healthcare and the internet, suddenly it's "SoCiAlIsM"