Which is accounted for by the energy payback time, which is generally less than 5 years since the nineties: https://www.bnl.gov/pv/files/pdf/PE_Magazine_Fthenakis_2_10_...

Current estimates are around 1 year for southern Europe and 1.2 years for northern Europe: https://www.ise.fraunhofer.de/content/dam/ise/de/documents/p...

What's not accounted for is decreasing EROI on mining the minerals needed to construct panels and the fact that the average lifespan of a panel is 2-3 decades (and the efficiency decreases with age) and then what? We have no recycling solutions in place. The amount of energy it would take to actually fully recycle these panels throws a big wrench in that calculation. We're already in the midst of a solar waste crisis and it's about to magnify significantly as these panels start dying out

And then of course there's the massive cost of batteries and all the mining and recycling issues associated with that

And what about the amount of space they take up relative to other energy sources? What about the costs of cleaning up all the lead and cadmium that leak into the environment?

Everything in your comment is false. That's an impressive performance.

There's no decreasing EROI on mining sand and bauxite.

The average lifespan of a panel is more like 60 years; 2-3 decades is just the design life. Of course some panels are defective.

Efficiency asymptotes to about 70% of initial efficiency.

There are a number of recycling solutions in place.

Making PV panels from PV panels takes less energy than making them from raw materials and not more.

There is no solar waste crisis.

There will be no solar waste crisis.

These panels aren't going to start dying out.

Batteries cost less than panels and have routinely been recycled for decades, because recycling them is lucrative.

The amount of space PV generation and batteries take up is irrelevantly tiny.

Modern solar panels and lithium-ion batteries contain no cadmium. PV panels do contain irrelevantly tiny amounts of metallic lead, which does not normally pose an environmental risk.

Cadmium telluride solar panels do contain cadmium, but they are no longer in wide use, because they cost too much to compete with polysilicon; because they are thin-film panels, the amount of cadmium they contain is irrelevantly tiny, and it is poorly soluble.

Discarded lead-acid batteries do not pose a significant environmental threat even if they fail to be recycled, because the lead they contain is not mobile.

I am at a loss as to how you managed to write a comment like this without accidentally slipping up and writing at least one statement that was correct.

Panels are almost exclusively sand. Should we run out of one of the things needed to make solar panels a recycling market will pop up. I also think you need to check your lifespan numbers. Solar panels degrade much slower than that, if they get thrown out after 20 years that has silly reasons like they stop getting subsidies after 20 years. There is a healthy market for used solar panels.

We don't have 'no' recycling solutions in place... There are currently at least six companies doing it in my country (Australia), surely we're not the only place this happens...

Also, please note that panels that contain cadmium are, I believe, around or less than 10% of solar panels produced.

And in a 100% solar economy, the energy to build and ship the panels would be solar. This is fine, as they output enough energy to make themselves in 1-4 years depending on which study you look at.

Using energy still generates heat, as per the laws of thermodynamics.

Converting sunlight to electric energy and then using that energy generates the exact same amount of heat as if that sunlight was simply absorbed by the ground without the solar panel being in the way, as per the laws of thermodynamics.

This is where I am curious to see if solar panels cover city rooftops can help - not entirely mitigate but help - with city heat island effects.

By absorbing the energy to then use it - say to run aircon - it should be better than having the surroundings absorb it and then pump in more energy from outside to mitigate it.

Though, if the solar panels absorb more energy than the ground, due to the ground reflecting more of the light, that’s still a little bit of difference, right?

(Not a knock on solar panels, I’m just being pedantic)

That depends on albedo.

https://en.wikipedia.org/wiki/Albedo

Yes, and?

Perhaps they are mixing up the “there is therefore a maximum safe rate of worldwide energy use (however far away we are from that)” point with the “CO2 emissions from fossil fuels contribute to greenhouse effect” point, and...

ok, I’m not sure either

Doesn't everything? It's not an issue so long as across it's life it results in less carbon production than alternative sources do per kW

That’s true but it’s also true for fossil and nuclear fuels.