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If the solar shingles last far longer than my current shingles (which actually need to be replaced soon), what about the degradation of the solar cells themselv

by smoyer 10y ago

If the solar shingles last far longer than my current shingles (which actually need to be replaced soon), what about the degradation of the solar cells themselves? Traditional PV panels degrade and have to be replaced sooner than many roofing materials.

jjawssd 10y ago
iirc 20 years is a typical rated lifespan of PV installations
denom 10y ago
In the linked video Elon mentions a "lifetime" of use. If that's true, then sign me up.
philipkglass 10y ago
There are a lot of different degradation mechanisms that affect silicon based PV modules. http://www1.eere.energy.gov/solar/pdfs/pvrw2010_wohlgemuth_silicon.pdf http://www1.eere.energy.gov/solar/pdfs/pvrw2010_wohlgemuth_s... Most typical failures are thermomechanical fatigue and chemical breakdown of encapsulant and backsheet materials. Musk said that these are made of quartz (vitreous silica?) which has a very low coefficient of thermal expansion and should reduce thermomechanical fatigue on connections. By all appearances these are glass on both sides, no backsheet polymer layer, hence no backsheet breakdown possible. These small modules are going to be more robust against mechanical damage than modules with larger surface areas. Both Silevo and Panasonic* base their cell technology on n-type monocrystalline silicon, which exhibits negligible light induced degradation over time (an optoelectronic effect which can gradually reduce efficiency of more common p-type cells). The glass-all-around design also eliminates the chances of potential induced degradation. The median degradation rate for crystalline silicon PV modules as a group is only 0.5% per year (meaning 86% of original rated output after 30 years) and these modules look like they can achieve significantly lower degradation rates than that. Poor execution can ruin any concept, of course, but these really look like they could work for several decades. *SolarCity acquired PV startup Silevo and originally intended to ramp the technology up to gigawatt manufacturing scale in a new factory in Buffalo, NY. More recently they've stated that Panasonic will run the Buffalo factory and the cell tech will be some kind of blend between Panasonic and Silevo; both companies' cell technology are based on heterojunction cell designs on n-type monocrystalline silicon substrates.
- igravious 10y ago
  Thanks for the informative comment. Tesla/SolarCity and Panasonic seem to be increasingly joined at the hip, don't they? That's be some merger. Who'd swallow who?

by smoyer 10y ago

jjawssd 10y ago

iirc 20 years is a typical rated lifespan of PV installations

denom 10y ago

In the linked video Elon mentions a "lifetime" of use. If that's true, then sign me up.

philipkglass 10y ago

There are a lot of different degradation mechanisms that affect silicon based PV modules. http://www1.eere.energy.gov/solar/pdfs/pvrw2010_wohlgemuth_silicon.pdf http://www1.eere.energy.gov/solar/pdfs/pvrw2010_wohlgemuth_s... Most typical failures are thermomechanical fatigue and chemical breakdown of encapsulant and backsheet materials. Musk said that these are made of quartz (vitreous silica?) which has a very low coefficient of thermal expansion and should reduce thermomechanical fatigue on connections. By all appearances these are glass on both sides, no backsheet polymer layer, hence no backsheet breakdown possible. These small modules are going to be more robust against mechanical damage than modules with larger surface areas. Both Silevo and Panasonic* base their cell technology on n-type monocrystalline silicon, which exhibits negligible light induced degradation over time (an optoelectronic effect which can gradually reduce efficiency of more common p-type cells). The glass-all-around design also eliminates the chances of potential induced degradation. The median degradation rate for crystalline silicon PV modules as a group is only 0.5% per year (meaning 86% of original rated output after 30 years) and these modules look like they can achieve significantly lower degradation rates than that. Poor execution can ruin any concept, of course, but these really look like they could work for several decades. *SolarCity acquired PV startup Silevo and originally intended to ramp the technology up to gigawatt manufacturing scale in a new factory in Buffalo, NY. More recently they've stated that Panasonic will run the Buffalo factory and the cell tech will be some kind of blend between Panasonic and Silevo; both companies' cell technology are based on heterojunction cell designs on n-type monocrystalline silicon substrates.

igravious 10y ago
Thanks for the informative comment. Tesla/SolarCity and Panasonic seem to be increasingly joined at the hip, don't they? That's be some merger. Who'd swallow who?