3 ms·

The most inefficient time to run your AC is when it is hottest, aka the time that most people are running their ACs and are unlikely to stop running their ACs.

by ouid 9y ago

The most inefficient time to run your AC is when it is hottest, aka the time that most people are running their ACs and are unlikely to stop running their ACs. Peak usage isn't as flexible as you seem to think. Also, hot days happen everywhere at once, so you can't even borrow power from other grids, because they are likely just as in need of power as you are.

WalterBright 9y ago
When it's hottest corresponds to when the solar panels work best, so there's that. Also, AC can be shifted. When power is cheap, use it to chill a tank of water or block of masonry, then use that coolness to reduce the AC load later. A tank of water can work just like a battery for HVAC.
- ouid 9y ago
  It's almost like you've forgotten the original argument.
- askvictor 9y ago
  Unfortunately, most solar panels point toward the equator for maximum overall power during the day. The highest demand for AC is in the afternoon; if panels faced West, they'd provide less overall power but more at peak times ( at least during summer)
- nkurz 9y ago
  When it's hottest corresponds to when the solar panels work best, so there's that. Sort of. Away from the equator, days are longer in the summer, so one gets more total energy per day during the season when it's hottest. But hour-by-hour, the peak temperature usually happens later in the day (mid-afternoon) than the potential peak solar production (noon). More pedantically, solar panels actually perform worse when they are hotter: https://www.thegreenage.co.uk/article/the-impact-of-temperature-on-solar-panels/ https://www.thegreenage.co.uk/article/the-impact-of-temperat.... The ideal for solar power would be full sun and frigid cold. In the extreme (Andean mountain versus Australian outback) this difference in efficiency might be as large as 50% (+25% for the cold, -25% for the hot). I agree with you that the "battery" doesn't necessarily need to store electricity, and that pre-cooling some large thermal mass might be better than a traditional battery.
  - WalterBright 9y ago
    It's hard to see how pre-cooling a thermal mass cannot help to be much more efficient than an electric battery.

by ouid 9y ago

WalterBright 9y ago

When it's hottest corresponds to when the solar panels work best, so there's that. Also, AC can be shifted. When power is cheap, use it to chill a tank of water or block of masonry, then use that coolness to reduce the AC load later. A tank of water can work just like a battery for HVAC.

ouid 9y ago
It's almost like you've forgotten the original argument.
askvictor 9y ago
Unfortunately, most solar panels point toward the equator for maximum overall power during the day. The highest demand for AC is in the afternoon; if panels faced West, they'd provide less overall power but more at peak times ( at least during summer)
nkurz 9y ago
When it's hottest corresponds to when the solar panels work best, so there's that. Sort of. Away from the equator, days are longer in the summer, so one gets more total energy per day during the season when it's hottest. But hour-by-hour, the peak temperature usually happens later in the day (mid-afternoon) than the potential peak solar production (noon). More pedantically, solar panels actually perform worse when they are hotter: https://www.thegreenage.co.uk/article/the-impact-of-temperature-on-solar-panels/ https://www.thegreenage.co.uk/article/the-impact-of-temperat.... The ideal for solar power would be full sun and frigid cold. In the extreme (Andean mountain versus Australian outback) this difference in efficiency might be as large as 50% (+25% for the cold, -25% for the hot). I agree with you that the "battery" doesn't necessarily need to store electricity, and that pre-cooling some large thermal mass might be better than a traditional battery.
- WalterBright 9y ago
  It's hard to see how pre-cooling a thermal mass cannot help to be much more efficient than an electric battery.