So, we moved out of our home with the solar panels and ended up having them for just over 2 years. The installation was mid-March 2013 and we sold the place in mid-August 2015.
We had a PPA with Solar City. In general, they were really good to work with.
Our rate was $60 / month with a 2% escalation annually and $0.11 / KWH. Our average bill prior to solar was $100 / month.
Most months we had no extra electric bill from Eversource. By the time we moved out, Eversource owed us $560.
We had the solar system for roughly 30 months. I’m estimating that over that time, we saved about $1760 ($40 / month * 30 months + $560).
If we had prepaid for the solar power, it would have been about $10k and brought our rate down to $0.05. However, since we moved before having the system for 10 years, it’s best we didn’t, as it’s unknown whether we would have recouped the cost in the sales price.
Needless to say, we’re looking into solar for our new house and depending on the economics, might purchase the system outright or do the lease & prepay for the electricity.
Here’s a brief summary of how I see the three options:
- PPA (Power Purchase Agreement) / lease: It’s the least risky, but you get the least savings. You don’t pay anything up front and the solar company gets the tax savings and renewable energy credits (NRECs). The company is responsible for monitoring the system, repairing it, and fixing your roof if there are any issues. You pay a preset monthly cost for the electricity generated by your panels and in some details, the cost will go up on an annual basis, however at a rate lower than projected for utility bills. The term is typically 20 years. It’s a great option if you don’t have a lot of cash on hand but want to get some savings, or if you’re not sure how long you’ll be in your place.
- pre-paid PPA. You get all of the benefits of the PPA (monitoring, repairs, etc), the company gets all the benefits of owning the system (credits, etc) but you’re lowering your effective cost of electricity from the panels by half or more by prepaying for the electricity. Depending on the size of your system, this could be $5k – $15k.
- Purchase the system outright. You own, monitor, maintain the system. The components all have warrantees but you’re responsible for getting the work done. This will be typically the most expensive option up front but give you the most savings over time. There are now solar loans out there to help people purchase systems more cheaply and easily. This could be the best option if you don’t have a lot of cash and know you’re going to stay in your place for a long time. The cost of solar systems is coming down all the time, making this a more affordable option than ever.