TL;DR: Get the largest solar system you can with enough batteries to run your house through the night. Don’t size the system for today, size the system for 10 years from now when everything you own is electric powered.

Details: It was not disclosed to us buying that our house lacked roof insulation. This created a charming oven effect on hot days where 80 degrees outside meant 90+ degrees inside. Needless to say, the HVAC didn’t make a dent even though it was over sized by 1 ton. The only positive was, the sun baking our house could become a massive amount of electricity if we installed solar.

The Tesla roof design process took 3 months because there were a lot of moving pieces. Retrofitting a roof with solar shingles means a new design each time, but they’re always improving the process. Buying a Tesla roof in 2021 felt like buying a Model S in 2016. Without early customers the Model 3 equivalent of mass market solar won’t exist, but with these customers it’s right around the corner.

I’ll try to keep my recap simple, here is what it looked like:

Original roof with double layer shingles, no insulation, janky skylight and hole where the chimney was.

Roof torn down to tar paper.

Roof after rigid foam and new decking was installed. Gray is Tesla peel and stick vapor barrier.

Final roof just prior to skylights going in and after remembering iphones take great panoramic pics.

Final product, ready for power on.

Here is a calculator I built to help evaluate the purchase: CALCULATOR

Pre-Work:

Upgrade the main panel from 100 amp to a 200 amp. They recommended a box with a single line to the sub panel so the Tesla team can easily install the power walls. I expect this recommendation will change, they wired the batteries to the sub panel, not the main. This was costly because I had them run new copper wire to the sub panel to replace the original aluminum wiring from 1964. There was also some reworking of the main wire into the house.
Add new roof decking. Our roof was only tongue & groove plus shingles, so rigid insulation and a plywood deck was needed. Tesla’s roofing contractors handled this, but it was a good chunk of the spend. You can see the breakdown below.
Removal of the chimney and gas vents . We didn’t want to burn wood in fire country California, so we had the chimney removed. We also removed the exhaust vents for the gas appliances like the water heater and the dryer. With less obstructions on the roof we had more room for electricity generating cells.
Removal of gutters, this came as a surprise, but the gutters needed to come off per Tesla. We are working with their roofing sub to replace them.

Installation: This part went quite quickly, 2.5 weeks start to finish. There were a couple ugly surprises like a kill switch by the main panel, which meant more boxes on the house. A positive surprise was they beefed the system up to 24 kWh at no extra charge. They estimate we’ll generate 34,000 kWh a year and I estimate we might use 6,000 to 8,000. Here is the original 18 kWh design, the white blocks were the planned photovoltaic tiles.

Products:

24 kWh 3,632 sqft Tesla Roof : $117k (BUY). Install Cost: $30k Pre-work, $47k Solar Roof Install, $40k Solar materials
Financing Charges: $5.5k ($110k financed over 10yrs at 1%)
2 Tesla Power Walls: $10.5k (BUY). Install Cost: Included with roof
Eaton 200Amp Main Panel: $355 (BUY) — Install Cost: $7.2k electrician
200Amp Sub Panel: $135 (BUY) — Install Cost: $1.7k electrician

Total Spent: Really $92k* (Technically $142k =$29.4k upfront + $112k over 10 years)

*To keep it apples to apples, my electrification spend on the roof is $92k because we needed a new $50k roof anyway.

Total Cost Offsets: $156.4k over 25 yrs ($36.9k solar tax credit + $67.5k utility bill reduction + $45k car fuel reduction + $7k income from solar sales)

Thats right, we will actually spend less over the long term than if we left everything as is.

Tesla Roof Shopping Tips:

Put $400 down to see the design and get near final costs HERE, it’s fully refundable. If you want to use my calculator, copy this google spreadsheet and play around HERE
If you need a new roof anyway, get the shingles. Otherwise, in 5–8 years when good looking solar is the norm, you’ll have to redo the work to maintain the value of the home.
Get the biggest system you can, a surplus of green energy will be very valuable over the next 10 years. As everyone tries to hit their 2030 climate change goals they’ll need your surplus. It also allows you to donate power to the grid to help reduce reliance on fossil fuels.
Give Tesla as much info about your roof as possible to get accurate pricing. Here is how mine ended up for a 3,600 sqft roof on a 2,400 sqft house. Keep in mind I was able to finance this over 10 years at a very low rate and I needed a new $50k roof anyway.

Want a Tesla Solar Roof? Save $300 on your Tesla roof with my referral code: http://ts.la/rick25647

Home Electrification: Turn Your Roof From Cost To Profit (4 of 4)