That's probably a bit absurd, and would probably cause a lot of changes since it would also mean that all the oceans are practically covered with panels.

Here's a reference to a study about large-scale panel installations:

https://www.science.org/content/article/solar-panel-shade-wo....

They suggest that there would be an impact, but far less than the impact of greenhouse gases they could replace.

In this case you are basically just changing the path of the light already hitting the planet. It will eventually become photons again and can leave back towards space, plus there is no release of greenhouse gases.

I guess it would still do something for the temperature of the planet, but to a far lesser extent.