(This comment is a US centric observation and may be somewhat relatable to other counties which use shingles. Solar shingles are not a thing in many many countries with billions of people, homes are built with concrete).
Solar shingles (Tesla roof, GAF) seem like a smart idea -- why do 2 layers of install, shingles and solar panels, instead save on both material and labor by using solar shingles.
It didn't work because the shingles are small, massively increasing the number of parts, connectors, and wiring -- and all the intensive skilled labor that it needs. Labor needs to be skilled as well as increases the number of hours. It also increases failure rates (at install time?) as well as lifecycle maintenance costs from repairs. Standard shingled roof (not the solar) is just an illegal immigrant working for $2/hour with a nail gun, unskilled labor, finishes things super super quick.
Could it work in future? We don't know. I think the fundamental constraint is people's existing belief system on what a roof is supposed to look like and unwillingness to consider that all roofs don't have to look the same. Perhaps its possible to let go of existing shingle design, build massive panels and make it a structural roof along with metal, but it may not have any buyers. And most definitely will not be accepted by any HOA. Most of the US in in a HOA regime. Any tiniest variation from the rigid HOA rules and regulations (slightly different shade) will require an entire roof rebuild. The constraint is not technological, but human beliefs (about what a roof should look like) and existing rigid structures on how we organized our society.
It doesn't blend with the surrounding slates (asphalt shingles are rare in the UK, use of asphalt is more for flat roofs and sheds), but .. how much does that really matter? It sounds like US HOAs have replicated the worst aspects of UK "conservation areas", preventing building variation, while not actually preserving anything other than a McMansion style of no historical or aesthetic importance?
I had that style of integrated panels installed on my (Victorian) house in the UK. The slates were old and crumbling so needed replacing and doing integrated panels meant only needing a fraction as much slate which saved a chunk of money. I think the result also looks a lot better than non-integrated panels, at least with slate roofs (which are common in my area)
Apparently integrated panels can be a little less efficient in hot weather as they don't get cooled by airflow under the panels and are less efficient when hotter. But it's a pretty minor effect, maybe a few percent of output. Seems like the best option on a new-build or if you're re-roofing anyway.
They also never managed the massive economies of scale for regular solar panels that have driven down prices. Solar panels that can be mounted on any kind of roof, in fields, etc.
Solar shingles (Tesla roof, GAF) seem like a smart idea -- why do 2 layers of install, shingles and solar panels, instead save on both material and labor by using solar shingles.
It didn't work because the shingles are small, massively increasing the number of parts, connectors, and wiring -- and all the intensive skilled labor that it needs. Labor needs to be skilled as well as increases the number of hours. It also increases failure rates (at install time?) as well as lifecycle maintenance costs from repairs. Standard shingled roof (not the solar) is just an illegal immigrant working for $2/hour with a nail gun, unskilled labor, finishes things super super quick.
The above is a manual summary from this insightful thread: https://news.ycombinator.com/item?id=48166226
Could it work in future? We don't know. I think the fundamental constraint is people's existing belief system on what a roof is supposed to look like and unwillingness to consider that all roofs don't have to look the same. Perhaps its possible to let go of existing shingle design, build massive panels and make it a structural roof along with metal, but it may not have any buyers. And most definitely will not be accepted by any HOA. Most of the US in in a HOA regime. Any tiniest variation from the rigid HOA rules and regulations (slightly different shade) will require an entire roof rebuild. The constraint is not technological, but human beliefs (about what a roof should look like) and existing rigid structures on how we organized our society.