[hollerith]

If the solar panel reflects less sunlight than what would otherwise be there (which seems likely to me) then grandparent is (technically) correct. The energy the panel absorbs eventually turns into heat (although before it becomes heat, it might in the form of electricity be transmitted far away) just like the sunlight energy that a rock absorbs also turns into heat.

The correct response to grandparent is that the magnitude of the increase in heat is small enough to be safely ignored.

[wjmao88]

It is more like

A. light absorbed by solar panels that eventually turn into heat

B. light absorbed by the ground which pretty much all becomes heat

I'm pretty sure B is much greater than A.

[hollerith]

Essentially all of it turns into heat except the part that is (immediately) reflected back into space -- and solar panels are darker than most of the (non-grassy or only sparsely grassy, and the grass is golden, not dark green or on the roof of a building) sites where solar panels are typically sited, which means they reflect less back into space. Ergo, erecting a solar panel adds heat (but again it is negligible compared to the reduction in co2 emissions).