Marketing and business model, primarily. Previous solar tiles were more expensive than conventional solar and so are these. The difference here is that Tesla and SolarCity are marketing it as no more expensive upfront than a conventional roof replacement by keeping ownership of the roof and having buyers sign a contract committing them to buying power from it at ever-increasing prices.

There also seems to be some efficiency and aesthetic improvements over previous tiles, but those alone wouldn't be enough to make it viable.

> Marketing and business model, primarily.

And from that, hopefully, scale. Solar tiles have always seemed to be a very poor relation of solar panels. The approximately 1x1.5m panel is a sort of informal global standard, and that's meant that solar tiles have been much more fragmented, much lower scale, and much more expensive.

On the other hand in theory these solar integrated building materials should greatly reduce the associated costs of installing panels - labour is usually something like half the cost of installing rooftop solar, but if you can install a solar roof without much more effort than a normal roof, those extra labour costs are massively reduced.

If you can leverage this labour cost advantage to ramp up scale of the tiles, and get them close to the per watt cost of traditional panels, this is how you can really make rooftop solar competitive. These labour costs are why rooftop solar is so much more expensive than utility solar. If you can greatly reduce them, total costs are much more tied to the cost of the tiles themselves, the inverter, and so on, where there is enormous leeway for ongoing reductions. Very exciting.

The price of PVs has fallen by multiple orders of magnitude in the past half century or so[0]. This is a staggering change!

[0] http://blogs-images.forbes.com/peterdiamandis/files/2014/09/...

Great comparison of solar price decline along side other fuels:

http://i.imgur.com/GCy6EVx.jpg

That graphic really drives the point home, but it needs to be plotted logarithmically to get a good comparison.

What is henry hub?

Natural gas spot market

I must admit I don't understand this graph, from the context, yes, but from the graph alone I don't

CIGS solar roofing tiles are (or were, not sure you can still get them) about 6% efficient. These are, according to what was in the TechCrunch article are over 20% efficient[1].

[1] I got there by taking the '98% as efficient as regular solar' from https://techcrunch.com/2016/10/28/these-are-teslas-stunning-... and the current 22% number advertised by Sunpower here : https://www.greentechmedia.com/articles/read/SunPower-Breaks...

DOW's CIGS was pretty garbage compared to Certainteed's Apollo II system, which achieved 13.2% efficiency. [1]

There are also up-and-coming competitors such as SunTegra that hit 14.6% [2].

It seems like asthetic options and possibly efficiency improvements is what will set this apart from previous stumblings in this space. We'll see how this looks in the real world!

[1]http://www.solarelectricsupply.com/apollo-ii-solar-roofing-s...

[2]http://www.suntegrasolar.com/suntegra-tiles

I didn't know that. I thought they were always in an r&d phase before.

From my research they have never really been competitive to the point of getting any traction in their installation. They cost a lot more and provided a lot less power compared to standard panels. This seems promising especially if it is available so that it can be installed directly by home owners.

>but I promise I'm not trying to be overly pessimistic or critical of what Tesla is doing

The fact that you have to apologize for this on HN nowadays is hilarious. I agree. Both solar panels (and to a lesser extent solar roofing tiles) and the powerwall are have a lot of competition.

The idea looks good, though. I didn't catch pricing details in the presentation?