> Increases the cost of homes

And decreases the energy bill by a very similar amount of what an increase in the mortgage would be if the cost was 100% passed on. Regardless, in much of California the price of homes has little to do with the cost of building them. So another possibility is buildable land gets a little cheaper because building is more expensive and homes are priced by what the market will bear, not by material cost.

I agree with you. I just finished installing a solar system that covers 1.5x my needs in my Southen California house. 5.4kw. My system cost installed was $2.61/watt - with $7000 being labor from a contractor and $6300 the hardware and panels. And my payback will be 4.2 years based on the past 29 months of usage.

Let us assume that there is simply a hardware expense because the builders already have roofers and electricians. It’s such a fraction of a mouse fart (as mentioned) that going solar will essentially pay for itself after 2 years.

I can see builders charging a premium for the "electric car package" or the "double your consumption" service but something like 3W of production for each square foot per month would be amazing.

> And decreases the energy bill by a very similar amount of what an increase in the mortgage would be

Sure, this is true iff a) the home has a nice south-facing roof, b) without trees in the way and c) under the current tariff design in most of California.

Some homes are built in wooded areas. Deciduous trees on the south side of the house (in the northern hemisphere) 1) shade in the summer, 2) allow the sun to warm in the winter are 3) are attractive.

Finally, regulated-monopoly utilities will continue to pass their costs to their customers. They will change the designs of their rates to continue to recoup their costs. So what might be saved in utilities costs today won't necessarily be saved over the life of the mortgage.

In most cases sure. But, there will always be corner cases, places where solar panels don't make economic sense.

> Increases the cost of homes

In a narrow sense; TCO, however, may be lower. (EDIT: TFA itself indicates +$9500 new home cost, -$19,000 30-year electricity cost as the average impact.)

> Gives solar power industry a boost in a way that's hard to get rid of--they will lobby to keep this even if other industries are around and it'll probably never change

Sure, the solar lobby will seek to preserve this as is as the landscape changes. Competing industries will seek either to remove or broaden it to accommodate other approaches to the same policy objective. The homebuilding industry lobbied against it, and it still was passed. “One industry will lobby to keep it” does not imply “it will never change”, or the past absence of the rule would never have changed.

> No incentive to research new energy technology in the meantime

Even with 100% residential solar deployment—not just on new construction—there’s a lot of energy demand that doesn't cover and plenty of incentive to find an efficient way of meeting that demand.

Also if power needs are being met through other green tech, shoehorning this specific approach seems like a bad investment.

The cost of homes in 2018 is primarily driven by how much people can get for a mortgage, not by the materials that go into building them.

If homes had to be built to a better standard by legislature (Better insulation, or solar roofing, or whatever), it would, in the long term, drive down the price of land, but keep home prices similar.

Not to mention that you cannot retrofit solar panels on a home at the same interest rate as you can get on a mortgage. Forcing banks to lend money for these installations actually makes it cheaper for the homeowner.