Tesla is already manufacturing solar shingles, they use tempered glass and are more than three times stronger than standard roofing tiles https://www.tesla.com/solarroof
Wiring up their solar shingles isn't cost effective due to labor. Their solar roofs is a negative income stream for Tesla. When is the last time you heard the Solar Roof grow into 'record breaking growth'? It hasn't and it won't because Tesla is still trying to make the labor expense cheaper.
Look into the labor it takes to install an entire Solar Roof vs installing a new roof plus traditional solar installation. On a dollar for dollar basis, it may look competitive but Tesla is selling their Solar Roof's at a loss.
Tesla is selling their Solar Roof at a loss. Not at a profit. It's labor intensive and they aren't growing at a fast rate because of that hidden expense.
Disclosure: I installed around 200kw of solar panels and did a decent amount of research into Tesla's Solar Roof since it seemed so novel and innovative. The wiring of the Solar Roof is much more complicated than what is publicly understood. Tesla's good at PR because most of the public are superficial in their understanding. Tesla most likely saves a lot of money in the manufacturing process of the solar shingles but they lose money due to their complicated wire installation process. How are those shingles connected on the underside? How are those wires protected from the elements, without affecting the plywood on the roof? Etc. These are simple questions that are often overlooked.
There's plenty of companies other than Tesla offering solar roof tiles who aren't selling at a loss. Wiring seems to be a simple case of plugging them in. How do Tesla manage to make this complex or labour intensive?
Wow. The UK link you provide is running at about ~$7.65 per watt. That's extreme/exorbitant plus their tiles look ugly and I doubt the resell value on the home will be as high as a Tesla Solar Roof (since aesthetics are king on homes).
Currently, even in Cali a solar system ranges at about $4-5 per watt. The cost to redo a roof depends on the size but almost certainly it would be cheaper than the extra $2.65-3.65 watt left over on using a conventional system and less long-term liability to homeowner to replace a roof and do conventional solar.
Also, let me further point out this system was a 2kw system which isn't enough to fully be energy independent as a home owner. Sizes range in the 5kw to 8kw, at least in the USA. So, that would add additional money into the equation and only further emphasize my statement on 'that's exorbitant'.
UK homes use far less electric than the US, and air conditioning is almost unheard of.
Commonest UK size for solar is currently 3-4kWp, which is plenty for household independence, and above 5 or 6 rare. Earlier systems were smaller as panels were costly. I think somewhere around 5 is the point an installation is considered commercial rather than domestic making larger even less attractive.
Exorbitant or not it pays based on UK electric prices and feed in tariffs.
Price-wise I think that may be a decade, perhaps more, out of date as they link to a long replaced grant scheme.
No idea of current prices, and Tesla are available here too. The couple of times I've seen solar tiles in situ (like I say, not common here), have been far more like the last photo than the first which stands out.
Tesla's problem isn't by intention. It's by NEC (and local) code requirement.
For the second question, why not lay it across the sub roof: Water can be very damaging. What insures those wires (over 20-30 years) will not be damaged? For a conventional solar installation the wires are elevated and protected due to the cavity of each panel. Local codes generally require that no wires touch the rooftop, so that prevents the daily ware/tare.
As for the latter idea, I do believe that's Tesla main goal. But to practically do this is an engineering feat that hasn't been solved yet. Can Tesla do it? Sure. But I haven't seen them invest in a solution yet. Heck, Elon is focusing on too much and not fixing this issue. It's okay, he's got bigger fish to fry. But since it's not solved, they will continue to live with this problem.
Look into the labor it takes to install an entire Solar Roof vs installing a new roof plus traditional solar installation. On a dollar for dollar basis, it may look competitive but Tesla is selling their Solar Roof's at a loss.
Tesla is selling their Solar Roof at a loss. Not at a profit. It's labor intensive and they aren't growing at a fast rate because of that hidden expense.
Disclosure: I installed around 200kw of solar panels and did a decent amount of research into Tesla's Solar Roof since it seemed so novel and innovative. The wiring of the Solar Roof is much more complicated than what is publicly understood. Tesla's good at PR because most of the public are superficial in their understanding. Tesla most likely saves a lot of money in the manufacturing process of the solar shingles but they lose money due to their complicated wire installation process. How are those shingles connected on the underside? How are those wires protected from the elements, without affecting the plywood on the roof? Etc. These are simple questions that are often overlooked.