[hunterpayne]

Ireland isn't sunny enough for solar to help with AGW. In fact, solar in Ireland actually just frontloads and exports to the 3rd world the CO2 generated. Oh, and the power to make PV panels...comes from coal. On the other hand, if you just put a windmill next to an Irish politician, you could power the entire country.

[bryanlarsen]

That would only be true if solar panels had be trashed and repurchased every 6 months. But instead they last > 25 years, and can be recycled rather than trashed.

[hunterpayne]

No, that's wishful thinking. You can have your own opinion, but not your own facts. Engineers actually calculate all this stuff. EROEI for instance means Energy Returned on Energy Invested. For renewables, its 4. That means under ideal conditions (albino of 1, 20 year lifetime), over the lifetime of the panel you get back 4x the energy that it took to extract the materials, make the panels and install them. So if you site the panel somewhere with an albino of .25 (Spain) you get about as much power out of them as they took to make and install. And that obviously doesn't actually help with AGW.

[gusgus01]

An of EROI of 4 would probably already include the poor sunlight conditions of Ireland or would be some old numbers based off old solar technology. Plus there's contention around EROI because it does ignore the fact that renewables can be recycled and many are used past their lifetimes, and of course it ignores the negative externalities of spewing the one time use fossil fuels into the atmosphere. There are plenty of studies and papers arguing over EROI and its veracity.

[tdb7893]

The ERoEI numbers seem to be under some dispute. This study estimates it at 9-10 in Switzerland.

https://www.sciencedirect.com/science/article/pii/S030142151...

Also you mention albino and I can't find what that would mean in this context. At first I assumed you meant albedo but that doesn't seem to contextually match either. So I might just be misunderstanding your post.

[bryanlarsen]

A quick Google shows EREOI of solar panels at 10-30 depending on study.

[hunterpayne]

The PV manufacturers themselves say its 4. Those studies you mention say you could make them at 10-30 in theory if you could somehow purify the poli-silica differently. If we made PVs in the west with natural gas (and carbon recapture), perhaps it could get to that number (but perhaps not). However, PVs aren't made in the west and the poli-silica isn't purified with gas but instead using coal. That's why those numbers are different. And for reference, we could have made those PVs in the west, however politicians chose not to.

[ben_w]

> The PV manufacturers themselves say its 4.

You've not cited anything for this so far as I can see, but this claim is obviously false.

Reason being, the entire system in my driveway will have paid for itself in one year, including delivery cost and inverter and the aluminium stand it's mounted on (the small bit of aluminium in the stand is the most energy intensive part of the whole kit), and the weakest part of that system still has a lifespan of 25-40 years, and even that as a % reduction in output from peak not as a hard cut-off.

Even if 100% of the cost was energy, even with the 5x price differential between where I am (Domestic Germany) and where they were made (Industrial China, where the low energy cost is… ah… due to renewables, because coal's really expensive :P), it's obviously not an ERoEI of 4 even on the low end of that lifespan.

Given all that and doing the maths, what I will need to replace and when (or rather, kids whose mother I have yet to meet will need to replace when I'm in a retirement home), the ERoEI is at a minimum 14 even if 100% of the cost of replacement panels is energy.

The cost is almost certainly less than 100% energy. Every step of the industrial process wants its own profit margin.

[NoLinkToMe]

I think you don't know what you're talking about.

For one the EROEI isn't 4 for renewables under ideal conditions, it differs wildly depending on the type and location and installation. It's true that for solar in Ireland (which are NOT ideal conditions) its on the low end, though still about twice as much as 4, and it's certainly not the case for wind which can have them as high as 20.

Second, I've got no clue what 'albino' is. Do you mean albedo? In that case, it's completely irrelevant for wind power. Ireland produces 20x more wind than solar, the latter is completely irrelevant in Ireland.

For solar albedo is relevant, but only if you have bifacial panels, which are still the minority.

In Spain albedo is relatively low but it has some of the highest direct sunshine hours in Europe. Albedo is high in places like the Nordics, which have fewer sunshine hours. In other words, EV is brilliant in Spain due to the abundant sun, yet surprisingly is still viable in a place like Norway precisely because of relatively high albedo, not in spite of it. This is why EROEI for solar in Spain can get up to 20. The idea that you get as much power as it took to make (EROEI of 1) is so wrong, and so obviously wrong, that it seems like you just don't have any idea what you're talking about.