Has anyone done any studies on the co2 emission of manufacturing one panel like this? Curious how long it will take to offset.
The carbon emissions depend on the energy mix of the supply chain (which is mostly in China, since Germany totally butchered domestic production). And the total climate effect is amplified by other emissions (leaking of technical gases in silicon production? But now I am way out of my field of expertise.)
OTOH hand to calculate the offset of emissions you need to know what is going on in the grid. If windmills are shut down around noon to make room for PV, the offset is zero.
Very important point that is often ignored.
Wonder if there is anything that can be done to lengthen the life of the panel as much as possible. I've read elsewhere that solar panels have a theoretical lifespan of 25 years with the panels slowly degrading and not failing all at once. I dont know if these specific panels are different but I wonder if the panels are kept clean or something if that would maximize the lifespan?
Right now owners of older rooftop photovoltaics in Germany swap functioning modules for newer ones with better efficiency.
Even if some small percentage of older modules fails it is probably not the fault of the cells but of connections in the module due to moisture. It is a system. In theory you can take the cells and build new modules. But that is too expensive compared to buying new modules.
Solar is one of those magical technologies that seems to keep giving in different ways.
Intensive investigations of Chinese "subsidies" from the US Department of Commerce have come up with embarrassingly little.
The current €0.100/Wp price level (12¢/Wp) combined with the US$0.08/kWh given above does give us an upper bound of 1500 hours of full sun for the energy payback time. At a Californian 29% capacity factor, that's 7 months of operation.
But in fact not 100% of the cost of the solar module is the cost of energy; there are some labor and raw materials costs as well, as well as capital costs and, astoundingly, some profit. So 3 months is probably a better estimate.
Energy payback time around one year (p. 8)
You are probably right about the glass. Processing glass in electric furnaces has been a well-established technology for many generations, but it is more expensive than fossil-fuel-fired furnaces, and is used for making more expensive kinds of glass. But the glass in solar panels is an especially cheap kind of glass.
Coal is probably the cheapest form of energy. https://www.coal-price.com/ says that currently in China coal is on the order of US$100 per tonne. Coal has up to 33MJ/kg, so that works out to 0.3¢ per megajoule, or 1.1¢ per kilowatt hour, or more if the US$100/tonne coal isn't the best anthracite. You probably can't literally run a glassmaking furnace with a coal firebox, because of the contaminants from the coal, but you almost certainly can't run it on cheaper energy than that. If 100% of the cost of the solar panels were coal energy instead of electric, that would extend my upper bound out from 7 months to a bit over 4 years.
This seems to be in rough agreement with Fraunhofer's more informed estimate that you cite.
Hard to imagine a large scale rollout like this would have been on the low quality side (plus hey its Germany after all).