At the Solar Decathlon information booths I signed up for consultations with three solar panel install companies. The one that represents Tesla products, and in fact will be changing their name to Tesla, is Solar City. I have looked at the specifications of their Panasonic panels and Powerwall and I was sold. When the representative came for his sales pitch he found he didn’t have to be very forceful as I had already determined that this was the company whose products I was most interested in purchasing.
Since I already signed up for the Tesla solar roof, I knew that there were some superior products available from this company. I’m pretty sure the Tesla roof would not be a great match for our mostly north facing and flat south facing roof. We have basically one roof area that would efficiently host solar panels and that is over the garage. So I signed up for a smaller solar panel production at 3.9 KW. We use approximately 9.5 KWh last year. So the new system will only meet about 46% of our energy use. Since we live in Colorado, an area that has high solar gain, it makes good sense to add solar.
I should have added solar two years ago when Xcel was offering rebates, but at that time it was difficult to get into the limited amount of money they were dedicating to solar and the products were less robust. Our system will still qualify for a federal tax rebate of 30%.
We will have to wait for a Powerwall because Elon Musk sent his entire existing production to Puerto Rico for disaster relief. That generous use of these solar battery backup systems made me more than willing to wait for a power wall myself.
The panels used will be Tesla’s version of the Panasonic 325 watt solar panel, one of the most efficient on the market.
Panasonic-VBHN325SA16
Energy Sage created this graph of the relative efficiencies of current solar panels by manufacturer.
Solar Panel Efficiencies
My system will be 12 of these panels that will fit on our garage roof. We will also have a grid tie inverter, probably Power One as that is another Tesla owned company (formerly Aurora) and a Tesla Powerwall battery backup.
Tesla Powerwall technical specs
Solar City like all the installers handles the entire process from site survey which we had yesterday, to engineering plan, to building permit, to Xcel energy application to final install and warranty. The warranty on the system production is for 20 years and on the battery backup is 10 years.
I’m excited about adding solar even though my challenge was originally to be Platinum LEED without the additional cost of a photovoltaic system. Being in contact with those who have the systems made me want to add one to our energy efficiency goals.