3 ms·

What good does PV generated energy make if all that energy is used to generate heat and evaporating water?

• jfengel 5mo ago
  Those are less of a problem. The heat was coming from the sun anyway. The water condenses out, so long as you haven't also increased the overall temperature in other ways. The CO2, by contrast, is the gift that keeps on giving. It absorbs extra heat every day and hangs onto it. It doesn't condense or break down. If that PV went to displacing sources of greenhouse gas, it would be a benefit. If all it's doing is running the plagiarism machine while we burn more and more "clean" coal, then we are in deep, deep trouble.
  • goda90 5mo ago
    Not all heat from the sun stays in the atmosphere though. How much does photovoltaic impact albedo and radiance through the atmosphere compared to natural landscapes? Of course that's infinitely better than GHG emissions and we have a lot of opportunity to put PV over asphalt and such, but it should give us pause in the pursuit of more and more consumption.
• api 5mo ago
  That’s what solar energy does when it hits the ground or the oceans. It turns into heat or evaporated water. The latter is why it rains. Harnessing it and piping it through extra steps only to end up as heat does nothing to the planet’s heat balance. All human energy use is tiny compared to total global solar flux. Like not even 1%. The data center water issue is a municipal management problem. The problem is that evaporative cooling is cheaper. If data centers are using too much water to the point that it’s causing problems for homes or agriculture, it means they are not being charged enough for that water. Charge them more and they will suddenly shift toward more closed loop cooling.
  • ajuc 5mo ago
    https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2008EO280001 https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2008EO28... Waste heat from human energy use is a real problem, it does influence Earth's temperature, minimally for now, but it will only grow. And it will be MUCH harder to solve than global warming.
    • api 5mo ago
      If we tame fusion at scale this could become an actual issue in the far future. As it stands we have nothing that can out-scale solar or wind. Fission maybe if we went all in on breeders and stuff but that would not be cost competitive with renewables plus batteries. Breeder cycle fission is complex and expensive. Hopefully if we get really good at fusion we will go LARP The Expanse with it instead of boiling the ocean.
      • ajuc 5mo ago
        It will become an issue in 150-200 years even if we just continue on our current trajectory.
        • api 5mo ago
          Only if exponential growth continues, but population growth is already falling off a cliff and that is the ultimate driver. If population stabilizes or contracts, then the only way this could happen is if per capita energy use continued to increase exponentially to the point that we were radiating enough heat to do this. That seems unlikely. The only scenario I can imagine where per capita energy use goes that high is the "The Expanse LARP" scenario where people are rocketing around on fusion rockets, and that's not on Earth anymore so it doesn't matter. What terrestrial products or services would demand power use per capita across the whole population that high?
          • ajuc 5mo ago
            AI will consume any amout of energy if you have enough demand.
  • Cthulhu_ 5mo ago
    This is the thing I don't get - lots of concerns about water shortages, but for some reason the price of water doesn't go up accordingly. In fact, large consumers of drinking water get a discount. It should be the other way around: consumers and public interest things like hospitals should get preference and low prices for water, corporations should pay more and invest in their own water systems, like collecting rainwater, cleaning surface water (thinking of NL here), or desalinating seawater (and handling the waste responsibly instead of putting it back in the sea).