Matt Zuba
by Matt Zuba
4 min read

We’ve wanted solar for at least the past 5 years. We even went so far as to get quotes 5 years ago and then decided against it when we didn’t feel we were going to be able to secure as good a deal as we were hoping we could get. We weighed options of financing and leasing and nothing seemed right for the long term. We’re refinancing our house, and we had built up plenty of equity so at this point solar seemed like a great idea.

When we previously looked at solar, the best deal at the time we were able to find was a 12.48 kW system from SunRun that would be leased over the course of 20 years. The total cost after all was said and done was going to be $48k. I could prepay the lease for $31k, or buy it outright for $52k. This did not include any batteries, it was a solar array only.

Contrast that to the option I’ve recently selected with Tesla. Now granted, prices have gone down a small bit for solar, however using a cash-out refi to pay for solar if you have a damn good interest rate is the optimal way to get the most bang for your buck. I opted to go with Tesla’s 12.24 kW system with 2 Powerwall batteries. Using the cash payment option and getting the federal tax credits brings the net cost down to just about $29K. Estimated finance charges by rolling it into the mortgage is about $13k for a total cost of $42k. Over the course of 20 years, that comes out to about $175/month, at least $50/month cheaper than my current average electric bill. That savings will only grow over time!

Thursday, September 3rd, 2020

It was easy to get started with Tesla. All you have to do is visit their website (referral link; you’ll get $100 back after system activation), fill out your address and average monthly electric bill and then you can configure your system and payment options. Tesla selects the system they think is most optimal based on your electric bill. In my case it was the 12.24 kW system. I added the Powerwall option as well. It defaulted to three; I updated it to two.

I entered my contact information and credit card info ($100 non-refundable deposit) and placed my order.

After submitting the application, I was immediately able to start the virtual home assessment via Tesla’s website. I was asked about various features of my home and then prompted on subsequent screens to upload pictures of things like my roof, electrical panel, garage and A/C system.

Friday, September 4th, 2020

I received an email and text from Ariana with Tesla Solar introducing herself and advising me that the design of my system was underway. She was able to quickly answer a few questions that I had around HOA approvals and timelines and then I was all set to wait for the design.

Later on in the evening, I received the initial design. The design document sent over included specs on the SolarEdge Inverter, Q.PEAK DUO panels and Powerwalls. In reviewing the initial design document, there was a note that the layout of the system did not match the order (layout was 11.9 kW, or 35 panels instead of the full 36) due to utility prohibitions.

I did some digging into APS’s rules around solar and found that there are two restrictions in play for my property: I have a 200 amp main breaker so I’m capped at a 15 kW system; and since I’m looking at a system greater than 10 kW, I’m capped at 1.5x my highest 1 hour demand in the last 12 months. Up until my latest bill, my largest billed demand was 8 kW, therefore capping me at a 12 kW system.

Fortunately, my latest bill that was about to be sent out had a demand of 8.36 kW, capping me at 12.54 kW system, allowing me to go with the full 36 panels. A few days later my billing cycle was up and I sent the newest bill with demand to Ariana so they could redesign with the full 36 panels.

Tuesday, September 29th, 2020

Got an email from Ariana and a notice from Tesla that new documents were available for me to review; including the revised design with all 36 panels, some APS documents to sign and a few other things. I signed all of the documents and then downloaded a copy of the design to submit to my HOA’s architectural committee.

The design ended up with 14 panels (4.76 kW) on the east face of the roof and 22 panels (7.48 kW) on the west. PVWatts estimates this will output 7700 kWh/year and 12073 kWh/year, respectively, for a total of 19773 kWh/year. Not far off from the first year estimate from Tesla of 18910 kWh.

Thursday, October 1st, 2020

I received approval from the HOA for the Solar project.

Tuesday, October 20th, 2020

Tesla completed the electrical plans and determined they would be able to accommodate whole-home backup with the two Powerwall batteries based on the loads in my electrical panel! I was sent the plans to review (which is awesome, because I like learning how this stuff works) and I received an email from APS seeking authorization for Tesla to submit applications on my behalf. I signed the paperwork (Docusign) and let my rep know they were good to move forward on their end.

Two days later, I received a notice from APS that an interconnection application had been submitted.

In reviewing the design document, I was pleasantly surprised to see that Tesla was including SolarEdge Power Optimizers in the design as well. These weren’t on the initial plans but I’m happy to see them included here.