By the way, I don't really understand what you mean by free energy, if it uses solar energy, I don't think it's free either because it still requires maintenance costs and capital to build it. So, what do you mean by free energy?
Above I showed using the RTX 4090 as an example that GPU mining is unprofitable even with free electricity. Free electricity is electricity that costs 0 cents. If you pay for electricity, then mining will only be profitable for YouTube bloggers who shoot content and earn money from advertising.