Re-roofing and Solar Panels

 Our solar panels have been performing very well since they were installed in 2015 - 5 and a half years ago.  We generate more electricity that we use, so we never have an electricity bill any more.

When it came time to have the underlayment on our roof replaced, we found out just how well they are working!   This photo shows the roof before the tiles were taken up to replace the underlayment.

The solar panels had to be removed in order to work on the roof, so they were out of commission for four weeks.    For those four weeks, we were not generating electricity and instead drawing from SDG&E lines.  That bill came to $750!

Those four weeks were in late September/early October which are heavy usage months.  Looking at past usage, I figure that during an average month we use 80% of the usage during those four weeks.  

Therefore,  each year we are saving ($750 x 80%) x 12 = $7,200 per year!   Since the panels cost us $23,500 after federal tax credit, that means they paid for themselves in 3.5 years!

A couple of points if you are thinking of installing solar:  First, install enough to cover your ENTIRE electric bill.  The reason I say this:  some folks only bought enough to cover the most expensive electricity tiers.   But guess what the electric company did?  Once enough people did that, they flattened the rates and made the lower tiers more expensive!   Best to be safe and cover your entire bill.

Second,  if your roof is over 15 years old, it is probably wise to replace your roof and install solar panels at the same time.  Why?  Because having roofers work on the roof could void your solar panel warranty, which is typically a long period such as 10 to 20 years.  You could have your solar panels removed and re-installed by the company that originally installed them, but that gets expensive fast.  That's what we did and our solar company charged us $150 per panel.  You do the math!  Our roofers told us that was a typical price, as they had talked to many of their customers about that.

If you have your solar installed at the same time as a re-roof,  then the roofers and solar installers can coordinate with each other and make sure they both understand what the other needs - and help protect both your solar and roof warranties.

I know, I know, it is hard to pony up the cash for a re-roof until your house really needs it.  But make sure you factor in what *not* doing that is going to cost you in a few years...