In the last of this series I covered some of the challenges we faced with Solar City during the design of our system. Things got even more complex when our local power company, National Grid, got involved.

National Grid-lock

Poor Panel LayoutThe next phase was one of National Grid throwing up one road block after another and Solar City trying to counter the moves. It was clear what the problem was – we would be shifting more than $170,000 of revenue from National Grid to Solar City with me getting a slight savings in return. Despite mandates to be “More Green” etc., the energy companies clearly have no interest in assisting customers to go solar.

Energy companies clearly have no interest in assisting customers to go solar.

The first issue they threw up was that they wouldn’t allow “net metering” (where you can feed back generated solar power) for two different meters at the same address. Solar City stepped up on this one and offered to join my two meters and upgrade my panel (from 400A to 600A) to support that. Accounting issues aside, I agreed to the proposed change and after another site visit and some engineering planning they had plans for it to work.

National Grid’s next move was to report that the transformer for my area was only capable of handling 23kW of generated power. My system design was for 56kW. This was the most serious setback. We needed to cut my generation down to 23kW or less. This meant dropping the farm completely and scaling the house from 35kW to 23kW.

Then at 23kW the design once more had layout issues that called for all of the front of my house to have panels and then only the right half (from the back) of one of the 3 surfaces of the rear of my house and that would have looked odd. So we scaled it back to just the front of the house with a 18kW total system.

Side note: In my area a 1kW system generates about 1,000 kWh of electricity per year. So a 18kW system will generate about 18,000 kWh. This isn’t exact and will vary based on where you live, roof angles and all sorts of other things.

I asked what would happen if someone else that lives near me wanted to go solar and was told that the maximum that could be connected for feedback is 23kW. I’ll consume 18kW of that so anyone else that lives near me will be severely limited. Evidently transformers cover about 8-12 houses in my area.

Sorry neighbors, I got in line for solar first!

Next Steps

With the huge sale back from 56kW to 18kW, a 68% drop in planned production, I’ll now only be covering 32% of my power needs with solar. This is despite the fact that I have more than ample qualified roof surface to generate 100% of my needs.

For the house alone I’ll be covering 49% of my power needs. With this large drop in planned generation I re-ran the numbers to check on the value of going solar and found out that I will still save $56,000 over the next 20 years. Not as much as the original savings of $105,000 but still worth doing.

My next surprise was a friendly note from Solar City on September 1st letting me know that my installation was scheduled for December 8th and 9th (due to system size which makes me really wonder considering that this system is tiny next to the originally planned one). That’s 3 months away and in the winter months in New England. They also said that inspections etc. would take 4-6 weeks so the “go live” date would be sometime in January 2015. That puts the project at about 10 months start to finish assuming all goes well from here and it will be going live during some of the least productive months of the year.

From the start Solar City has made a number of mistakes from miss-sizing the system, to not knowing the requirements/restrictions of the local power company, to not following owner requests for layout and to not understanding power generation limits imposed by the power company. Many of these are likely do to slower adoption in my area of the country and struggling to keep up with rapid growth and the ongoing battle with the power companies, but they could have done a lot better in setting and managing expectations appropriately.

My experience with Solar City has led me to conclude that they’re not ready for widespread adoption outside of key markets and have a lot of work and learning to do before they will be ready for that next stage of growth.

I expect/hope that my next update will be post installation sometime between now and the end of the year. Stay tuned.