Yesterday, the California Energy Commission unanimously approved the nation's first commitment to putting solar on qualifying new home construction starting in 2020 - a move that'll be good for our cost-of-living and our climate alike.
Building solar on new homes is consistent with California’s zero net energy goals for new buildings, and it’s a great way of getting rooftop solar built cheaply for customers. That’s because when you install solar PV at the time of construction, you get economies of scale and save big on non-hardware costs like customer acquisition, permitting and financing. Reducing these soft costs, which can account for as much as 65% of a new solar system, means that the small increase in the home cost from the solar will be outweighed by net energy bill savings from that same solar.
We did some quick calculations to illustrate this, keeping in mind that solar equipment only accounts for about a quarter to a third of total solar panel system costs.
Assuming modules are 40 cents/W and the other system components and equipment costs are 85 cents, and then you add in a 10% profit margin for the builder, that would be a cost of $1.40 per watt, or $4200 for a 3 kW system. If you wrap that in a 30-year mortgage at a 3.92 percent interest rate, the incremental monthly mortgage cost is about $20.
Under the current net metering tariff and TOU B rate, a TOU residential customer in the Central Valley would save $85 a month on their electricity bill from that solar array, resulting in a net savings of $65 a month for new homeowners. There is an undeniable financial benefit for future homeowners of new construction with solar.
Yesterday's historic measure was years in the making and involved a broad and thorough stakeholder process to ensure that California gets this right. Thanks to the CEC, staff, and experts who dedicated time and resources to get it across the finish line.