[ars]

It probably could, if we spent enough resources on it. It's just not worth it, Nuclear is better for the environment.

Photovoltaics could not do it, no way. But solar thermal probably could. Storing power would require immense amounts of land for pumped water storage, but we could do it.

We'd also need huge amount of land for the solar collectors, but we could do it.

And huge amounts of copper for power lines and transformers. Again, possible.

But none of that is worth it, not when we have something as good as nuclear.

[throwaway5752]

That must be news about how photovoltaics could not meet global energy needs. Last I'd read up, global capacity with realistic assumptions was 3 times current energy use. Also, it's already cheaper per kWh than nuclear (fully depreciated). Also, nuclear is non-renewable. It's still flipping the bird to future generations.

Perhaps you are conflating capacity with transmission and storage?

[ars]

It costs too much energy to make a solar cell. Solar thermal at scale uses less energy for what it returns.

[throwaway5752]

See my reply to you here: https://news.ycombinator.com/item?id=8248640

Also, I don't understand your response. 1.) what is "too much" energy. 2.) what's your source on solar thermal vs PV EROEI at scale? 3.) what's the relevance of the solar thermal vs PV comparison, since every building in the US can have solar on the roof but not solar thermal. 4.) what's the relevance of your response to what I said?

[ars]

> what is "too much" energy.

More energy than it costs to make them, or at least enough energy that it's better to build something else.

> what's your source on solar thermal vs PV EROEI at scale?

Solar thermal just needs a mirror (ideally aluminium rather than glass and silver) and the rest of the plant is the same as a regular power plant. A mirror costs less than fuel I'm sure.

Solar cells need ultra pure silicon which is very very expensive to make.

> what's the relevance of the solar thermal vs PV comparison, since every building in the US can have solar on the roof

What would be the point if the energy return is not there?

> 4.) what's the relevance of your response to what I said?

I said they could meet global energy needs, just that it's not worth it. You assumed for some odd reason that I said they could not, so I figured you were asking about a comparison.

[lutusp]

> Solar cells need ultra pure silicon which is very very expensive to make.

So sayeth the poster, sitting at a computer filed with the same kind of silicon out of which panels are made. The reason solar panels are so cheap to buy, is because they're cheap to build.

> What would be the point if the energy return is not there?

Everything except evidence that this is so. If solar panels didn't pay for themselves, people wouldn't buy them.

[ljf]

A reply to ars - a 1cm piece costs 200 dollars? Because I've got a solar pocket calculator here that I'm sure I picked up for £2 and I am pretty sure wasn't subsidised. Been doing its job for a very long time too...

[ars]

> So sayeth the poster, sitting at a computer filed with the same kind of silicon out of which panels are made.

And very expensive it is indeed. A piece about 1cm square costs $200 or more. Solar panels need square meters of the stuff.

> If solar panels didn't pay for themselves, people wouldn't buy them.

Exactly my argument. Thank you. People in fact don't buy them - except when they get subsidies that artificially reduce the price.

[lutusp]

> It costs too much energy to make a solar cell.

Compared to what? Solar cells last a long time, and in sunny climates generate a lot of power, far more than enough to pay back the energy cost of their construction.

> Solar thermal at scale uses less energy for what it returns.

That may be true, but don't dismiss solar panels, in particular in remote locations where there's adequate sunlight.