[Stu from NYC]

Originally Posted by retiredguy123

OP, when evaluating the monetary aspects of a solar system, make sure that anyone who does an analysis includes the time value of money. If the system costs $20,000 to install, you will lose the investment income from that money, and when the system reaches it's useful life span, you will lose the entire $20,000 investment because the system will be worth nothing. In my case, a solar system would cost about $20,000. My conservative diversified portfolio of stocks, bonds, and cash earns an income of about 6 percent per year, and will always maintain the $20,000 principal. So, for my house, if I buy a $20,000 solar system, I would lose $1,200 per year in income, and I would lose the $20,000. That is about the same amount as my entire annual electric bill. So, even if the solar system reduces my electric bill to zero, I would not benefit at all financially from buying the system.

Many solar contractors and other proponents of solar systems, will give you a payback analysis that totally ignores the time value of money. And, they ignore the fact that, over time, the system will depreciate in value to zero. Also, when you replace your roof in about 15 years, you will incur a large expense to remove and replace the solar panels. Another point is that some solar contractors will give you a 20-25 year parts and labor warranty on the system, which is totally unrealistic. No contractor can expect to honor that type of warranty on any equipment installed on your house.

Not to mention not too many of us can expect to be around in 20-25 years and suspect that when you sell your home they void warranty.