Solar PV Tiles vs new roof

[Giff]

@evertruelife

there is a new option now, to use PV tiles directly - technology that is new and might be more rational in the future instead of separately doing roof then PV.

Only I have heard these tiles cost a lot.

[evertruelife]

They are not more expensive than total cost of replacing roof and then installing additional PVs.

[Ilpiccone]

@evertruelife

Btw, there is a new option now, to use PV tiles directly - technology that is new and might be more rational in the future instead of separately doing roof then PV.)

Beside the better optics - usually not worth it. Its oftrn more expensive then doing a roof and separate solar.
Less efficient as its heating up more in summer.
A solid new roof as a useful life of easily 60-80 years and more.
Solar can be end of life in 25 years (at least with much less output). The. You can only replace the solar layer with much better panels by then - not so easy with the integrated solar roof.

[nabalzbhf]

@Ilpiccone

Solar can be end of life in 25 years (at least with much less output).

FWIW, it looks like that PV have much better durability than initially thought:

Three decades, three climates: environmental and material impacts on the...

(I think good manufacturers are targeting >50y lifetime now?)

edit: that said given efficiency improvements, might still make sense to replace before EoL? I guess it depends if the house is energy sufficient or not.

edit2: that said they’re a bit cautious wrt latest generation:

The rapid technological evolution and changes in module design and material selection over the last five years could potentially undermine the performance seen in older systems.

[Ilpiccone]

True, 25 years ago panels were almost half as efficient as today. But today we seem to be close to the theoretical max efficiency. So the gains in the next 25 years might be only marginal compared to earlier.

On the other hand a bigger reason against using integrated solar panels as they might be harder to replace if something breaks (is the same product still built 20 years later?.. 40 years?) etc..

[Daniel]

@evertruelife

Btw, there is a new option now, to use PV tiles directly - technology that is new and might be more rational in the future instead of separately doing roof then PV.

I wouldn’t recommend solar roof tiles for these reasons:

• Replacing solar panels once they lose their zing requires replacing the whole roof, as opposed to simply replacing external solar panels.
• Servicing and repairs require messing with your roof, and must always be done one site.
• They have a shorter lifespan than clay tiles.
• They lose value as more powerful solar panels become available.
• They produce much less power per square meter than stand-alone solar panel units because of power lost in transmission.

Their heart’s in the right place, but the execution is still a long way off. Might get there someday.