I got a quote from them, but they were higher than others. I went with a local installer who gave, by far, the best price. The big outfits like Sun Run often have local guys do their work. The nice thing for me: I call or text my installer, and he responds right away.

Get a few different quotes. I found that each company would give different recommendations. One gave a quote with panels on the north side of my house. Others said that I couldn't get anything bigger than 12k on my south side, leaving me short of my total use. My installer was right on with his estimate at 18.8k. He was significantly cheaper as well. By getting multiple quotes, I got a sense of what I needed and, by the end, it was an easy decision.

Actually, SunRun cancelled my installation saying that I had too much shade. Same problem with Solar City, so I guess I won't be using solar on that house.

I'm still trying to figure out my vacation home, which was designed for solar. My quote for a system large enough to cover my entire annual electric use was $43,000 (about $25K after rebates), which gives me a 10 year ROI. This would be a purchased system; neither SunRun nor Solar City does installations in my vacation home area.

So, I just re-did the financial calculation, and either I did something wrong, or it's not worth it. If I borrowed the $25k from a bank, at 2%, and paid the bank what we are now spending on our electricity ($1800 per year), it would take 197 months, or over 16 years to pay off the loan. Of course, I would be paying no more than I am paying the electric company without the solar, assuming no increase in electric rates (ha ha) and no increase in my interest rate (also ha ha). So my 10 year ROI seems optimistic!

David,

An acronym dictionary that I just consulted, lists 125 different meanings to "PPA". I presume that the meaning of "PPA" in your case, means that you are purchasing a system rather than leasing it. There is an excellent article in the August 2016 edition of Consumer Report magazine that compares the financials of :

1. Purchasing a system by paying cash

2. Purchasing a system by financing it with a secured loan (HELOC)

3. Leasing a system

In the example presented, the savings are highest with option 1; next highest with option 2; and the least with option 3. Also, there are some unique and expensive problems that you can encounter if you lease as opposed to owning a system if you ever decide to sell your home.

But the financial benefit of owning a system at all, is dependent on cost of energy in your area and the purchase price of your system. If the cost of electricity in your area is low (or if the cost of the system is very high), it could take so long to recover a return on your investment in a solar energy system, that the advantage of installing it, is minimal and perhaps not worth the effort.

Here in northern California, we have some of the highest utility rates in the country. Our 4 tier pricing structure begins at $0.18 per Kwh and goes up to $0.40 per Kwh. Our average cost for our electric bills over the year, is around $320 per month. When we had guests with an infant visiting last summer, we ran our air conditioner continuously and had an electrical bill of over $600; the majority of our bill was at the rate of $0.40 per Kwh

We just had a 8.5Kwh system installed yesterday; it will be turned on today. The company designed our system based on our utility bills over the past year. They prepared a detailed report that computed that our system will pay for itself in around 7 years. Our electric bill per year will be $120 ($10 per month), so that we can access the grid, to sell our surplus electrical production and to provide us with power in the evenings and during winter days when the system does not provide enough energy for our daily use. Assuming an increase in the cost of electrical energy of 5% per year, the company's program computed a return of over $155,000 over the 25 year life of this system. California has more solar energy systems than any other state. It makes a lot of sense to go solar here because

1. The cost of electricity from the utility companies is so high.

2. We have over 300 sunny days per year.

3. The intensity of light reaching the ground is very high, due to the low amount of humidity in the air.

4. Solar energy systems pay for themselves in a reasonable amount of time.

We bought panels produced by one of the leading US companies, SunPower. In their specifications handout, they indicate that the output of the panels can degrade by something like 0.5% per year. The SunPower brochure states that by year 25, that the panels will still be producing around 87% of what they did in year 1. I suppose that if this is a problem for us, we could simply add another panel or 2 from the $155,00 we saved in our utility bills from year 7 to 25!

If you are worrying about producing too much electricity in the future, buy an electric car!

Good luck with your decision,

John

Oops, the entry above was intended for a different thread

John_CA - even though your response was for a different thread, I found it useful. My calculation assumed that no increase in the comparable utility costs. In our area, overproducing is not financially useful because I would be paid only the wholesale rate of $.02/kWh. I also did not consider that the utility might charge me for accessing the grid. I'm not sure how CA utilities handle the charges, but here in northern NY, they compare the amount taken from the grid with the amount put into the grid, annually. The system is designed to maximize annual solar input, which means optimizing for summer.