Home Improvement → Re: [Green Tech] Solar panels: doing the math...

First, I would call some customer references and then at least 1 other installer (if there is one).

Then think about the decision. Careful on the thought "my electricity would end up being virtually no cost". Don't focus on that thought as a mental reason to do it. Because it isn't 100% exactly true and is open to change as solar catches on and the POCOs get grumpy about it. Also, mother nature can ruin your production values on a whim. Oh look, the Northeast hasn't been overly cloudy for the past 3 years. Let's make it look like Seattle. THAT will ruin your day.

The other thing from "my momma always says book": if your gut is telling you not to do it, don't.

Cho Baka - Thanks for the input.

ke4pym - You've hit on two concerns that are beyond my (or the installer's) control. CT is notorious for changing the rules of the game while the game is in progress. Nothing is stopping CL&P from asking for and getting a change to the way net metering is calculated. And that could have a profound impact on the payback time frame.

And while this winter hasn't been horrific, I looked up to my roof today... and saw a complete covering of snow somewhere between 6" and a foot. With cold temps continuing for the foreseeable future, I would be generating darn close to zero power. And typical winter snow here runs from December to early March. There are always exceptions, but there could be weeks and weeks of zero electrical production based on snow coverage- and given the roof's height, it would not be possible nor practical to use a soft roof rake to clean the panels.

Lots of variables that make the estimates just that- best case estimates.

I could put up a 5kWish system to pick up some of the summer A/C slack, not looking to completely replace my power source. Payback would be much shorter, and then I wouldn't feel too concerned with low production months. I'm sure from April to October, those panels would produce just fine.

The other thought I had was to size the system at thirty 327 watt panels to max out just under 10kW, which maximizes the state rebate and shaves quite a bit of unsubsidized cost off the price (and much time off the payback).

Then, if I need to supplement during peak usage, so be it, but a good chunk of my power will be home generated at the best price possible.

Snow melts really quick from the panels. I've only had 1 "major" snow fall (that looks to be changing mid-week) and it was a heavy snow. Within a day, the panels were clear. But keep out from under them. You get a sno-vah-lanche going on.

Decision made. I can't make the numbers work, even after trying a few different wattage scenarios. Payback time remains stubbornly high around 9 years, and neither FHA Powersaver loans nor Sunpower's loans can get me to within a few dollars of breakeven with my current average monthly bill. I'd be eating a higher total cost month after month for years in the hopes that one day (at least nine years in the future) power would become less expensive. Way too many variables along the way as well. And so, I'll close the book on this one...

But you know, I learned a lot along the way, and researched this concept to its conclusion, so I don't view any of it as a waste of time. Maybe some day the math will work... but unfortunately not today.

Thanks for all your input everyone!