[zahlman]

> For example, the solar PV when sited in Minnesota is so inefficient just making the electricity from natural gas would produce less CO2 per watt.

How does electricity from solar PV ever make any CO2 whatsoever under any circumstances (never mind, somehow more than natural gas)?

[hunterpayne]

Because the PV panel itself has to be manufactured. And under ideal conditions, the amount of power needed to make the panel is about 5 years of what the panel produces. Most of the power goes to purify the poli-silica that makes the bulk of the panel itself. If the PV panel is sited somewhere with less than 25% of the ideal amount of sun, then its manufacture makes more CO2 than the power it will replace on the grid. Minnesota is uniquely bad for site siting. Its at a low elevation with lots of cloud coverage and its far to the north of where the breakeven line for solar PV.

PS Did you think solar PV was made from unicorns or something? Making stuff requires power, unless you are making that power from hydro or nuclear, that's going to make a lot of CO2.

[zahlman]

Okay, so you are indeed talking about total lifecycle footprint rather than marginal footprint (which is strange to me because discussion of fossil fuels rarely mentions the carbon footprint of building the plants). The electricity generation is not actually producing the CO2 here, of course, which was my point.

Regardless, I don't know where you're getting your information or arguments, but you're way off base. Mining and refinement are more like a quarter of the power input, and many parts of the process can be electrified and don't require high temperatures (i.e. can themselves run on clean power once you bootstrap it). Solar panels typically pay off the energy cost of manufacture within a few years, but are expected to last for 30 (and inverters for 15). IEA studies (e.g. https://iea-pvps.org/wp-content/uploads/2024/05/Slides_IEA-P... ) show a similar story for carbon; amortized over the lifecycle, the carbon intensity is on the order of a few dozen grams/kW, where natural gas is an order of magnitude worse just counting the combustion (and coal is even worse, of course). And those numbers are from 2023; things have only improved (certainly in terms of cost per panel).

They have solar power working effectively across Europe, particularly in Germany (Wikipedia tells us it's about 1/6 of power generation there), despite significantly less sun than Minnesota. It's actually only slightly more cloudy or less sunny in Minneapolis than in Kansas City, MO (again per Wikipedia); cross-referencing a few things, we can easily find that, far from "less than 25%", Minnesota sees almost half the maximum solar yield. As for elevation, that's obviously irrelevant unless you happen to be right next to something taller.

The condescension is really not necessary.