Yes but... In Factorio, the only cost is the original manufacturing costs. The same goes for storage. Once manufactured and placed, they will produce power forever as long as it is daylight. The capacitors will also last forever. There are no weather patterns to mess up production.

In other words, once you make one, you have a permanent power increase. Your power can grow exponentially if you just focus on building and placing panels. That makes them the absolute best power source in the game. Not the most compact, though. But that doesn't matter since the map is infinite and there are no transmission losses.

Reality is not as forgiving. We'll need more panels. Way more :) Even more if we start doing things like fuel synthesis. But we should.

I has always bugged me that we use dirty power during summer to... power ACs! We have all this extra energy literally falling from the sky. Which is the whole reason why we want to get rid of it. Air conditioning doesn't actually require that much power to run with proper insulation. People have been able to power large RV air conditioning with solar alone.