solar panel salvation

[Gian]

If there were enough solar panels installed across the world, besides give us lots of cheap energy would this also reverse the effects of global warming? If so, how many would be needed?

cheerz

Gian

[iNow]

What do you mean “reverse the effects of global warming?” The chemistry reactions taking place in our atmosphere will be unchanged by solar panels. They can only hope to prevent more CO2 from being added. 

[swansont]

The solar energy converted to electricity means there will be less heat absorbed by the earth, but since energy is conserved it's just going to show up somewhere else. Anything you do with the electricity will eventually involve waste heat. If you've changed the albedo (reflection vs absorption) that will have an effect. It's possible that you increase the absorption with the panels, though, since they are designed to absorb the light rather than reflect it — you'd have to compare it to the ground it's covering. The win, as iNow notes, is not adding CO2 to the atmosphere, which amplifies the effect of the solar heating.

 

[Gian]

inow and swansont

Well yes,  hopefully sunlight could be turned into energy in another form eg motion and/or light. Yes there would be waste heat but presumably not as much as if the sunlight energy had not absorbed at all. And yes a percentage of the 'harvested' sunlight would also be reflected away from the Earth.

Presumably if if it was done on a big enough scale there would be a net cooling of the Earth, plus an additional reduction of CO2-producing forms of energy production?

cheerz

Gian

[iNow]

I was with you until the mention of net cooling. The CO2 currently in the atmosphere will remain there for thousands of years. We might cool, but if we do it’ll likely be because we altered the ocean currents and glaciation is occurring. Reflecting sunlight away will lead to bigger problems (such as those we see when massive volcano eruptions blanket the sky with dust and ash and kill most life). 

[studiot]

1 hour ago, iNow said:

We might cool, but if we do it’ll likely be because we altered the ocean currents and glaciation is occurring.

 

Inappropriately altering the ocean currents is one of the greatest dangers we face.
There is an enormous disparity between the solar energy received in equatorial regions and that received in higher latitudes, both north and south.
It is the world ocean circulation currents (now known as the conveyor) which distribute some of this energy to higher latitudes permitting the temperate zones to exist.

[J.C.MacSwell]

2 hours ago, iNow said:

I was with you until the mention of net cooling. The CO2 currently in the atmosphere will remain there for thousands of years. We might cool, but if we do it’ll likely be because we altered the ocean currents and glaciation is occurring. Reflecting sunlight away will lead to bigger problems (such as those we see when massive volcano eruptions blanket the sky with dust and ash and kill most life). 

Not necessarily though. Currently we are absorbing and holding more energy than we have in the recent past...thus the global warming.

Some reduction, especially if targeted for reasons Studiot alludes to, could minimize or reverse some of the detrimental effects (or not... for reasons you might be considering)