Since current energy storage solutions are more resource intensive (and polluting) to make than energy generation, we need on-demand energy generation.
Solar (and wind) of x MW average power means at least 2x of max power, and thus needs at least 2x of 'reserve' non-solar power to cover the gaps when it's not being produced due to daytime or weather.
This means that solar, even if it'd be completely free and perfect, can't fill a majority of global energy needs - I'd guess that a third would be an absolute maximum unless/until we get radical breakthroughs in energy storage technology.
Those types of unpredictable energy don't replace other power plants, as those nonrenewable power plants are needed anyway - they only save fuel for those plants by allowing them to reduce load at random times.
Solar and wind energy are perfectly predictable: www.energymeteo.com
There are fluktuations every day due to the differend demand and loads in any case. Thats why you link many sources together in a Virtual Power Plant. Works quite well. The biggest Virtual Power Plant in Germany is the one of Statkraft (a Norwegian Company); it has about 8GW capacity.
That is a great point, and I do think that large scale transmission (closer to a global grid) and energy storage advancements are possible, but so far have suffered from a chick/egg problems. But even so I think there's a legit place for spot generation from whatever origin (probably methane powered turbines) in a balanced energy roadmap.
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.
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?
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?
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.
> 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.
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.
Solar (and wind) of x MW average power means at least 2x of max power, and thus needs at least 2x of 'reserve' non-solar power to cover the gaps when it's not being produced due to daytime or weather.
This means that solar, even if it'd be completely free and perfect, can't fill a majority of global energy needs - I'd guess that a third would be an absolute maximum unless/until we get radical breakthroughs in energy storage technology.
Those types of unpredictable energy don't replace other power plants, as those nonrenewable power plants are needed anyway - they only save fuel for those plants by allowing them to reduce load at random times.