If all of mankind’s energy was supplied through solar panels would the effect be big enough to decrease the temperature (since light is converted in part to electricity)?
If all of mankind’s energy was supplied through solar panels would the effect be big enough to decrease the temperature (since light is converted in part to electricity)?
No. If a watt worth of sunlight hits the earth, it’s transformed into a watt of heat. If it hits a solar panel, it’s transformed into some heat and some electricity, which is then used to power something that then transformed it into heat. The only solar energy that doesn’t heat up the planet is the one that is reflected back into space, which, however, isn’t much for solar panels.
However, if you use a watt of sunlight to power your phone instead of a watt of energy you got from burning coal, this watt of energy instead stays below earth and therefore doesn’t heat up the planet. It also doesn’t release co2, which would otherwise reduce the atmosphere’s reflectivity, trapping even more sun heat on the planet.
So solar panels don’t reduce the temperature by not allowing sunlight to heat up the planet, they decrease the temperature by replacing other stuff that would otherwise heat up the planet.
Just note that the released energy of burning fossils (or nuclear) is orders of magnitude below what the sun does. It really is only the CO2 from coal (or CO2 and CH4 from natural gas, …) that does the heating, since it acts like insulation.
Yeah, that explanation sounded off to me. CO2 and other greenhouse gases are the issue, not heat directly released from combustion. The sun is doing the overwhelming majority of heating. Carbon staying underground matters far more than watts staying underground.