Should We Go Solar?
I’ve been writing about alternative energy quite a bit lately and my interest in the subject goes deeper than blog posts. The fact is the thought of paying $3 to $5 per gallon of propane to heat our domestic water and our home is really wearing on me. I can’t help but wonder where the extra money will come from in our family budget. What really wears on me is why didn’t I evaluate these issues when we built this new house two years ago? Since I can’t go back in time I’m forced to evaluate spending a significant investment on a new home!
So I posed the question to a friend of mine Paul who designs solar hot water systems: Can you tell me what a solar hot water system would cost and look like for our new home? He said sure no problem just give me some basic information. First off you really do need a roof that faces as close to south as possible. Our roof faces 27 degrees west of south which I’m told should work pretty well. All he needed was the roof position, i.e. southern exposure, physical location, i.e., long. and lat., and then the number of people living in the home.
Next thing I know I get an email back from him with some preliminary results. His calculations show that I need two (2) 4 ft x 10 ft solar panels with an 80 gallon storage tank. Given that design the following chart shows the percentage of solar hot water that the system could generate compared to our hot water need (domestic hot water).
As you can see from the graph I would have 100% of the hot water I need for 6 months of the year and almost 50% of what we need for 3 more months. 3 months out of the year would really not produce much if any hot water. Paul points out that the panel angles could be adjusted slightly to lower the summer output and increase the winter output to try and maximize the results.
So my next question is what would a system look like if I wanted to try and collect hot water to use with our radiant heat system. Paul says he needs some more info from me before he can run those numbers. What I’d like to do is present a cost comparison of both systems along with a return on investment (ROI). I’ll also investigate what federal and local incentives and rebates are available. Stay tuned for further discussions on this topic as I evaluate whether or not solar power would be a good investment for us.
(What would be really cool is if some solar manufacturer wanted to “donate” products in return for some great exposure on this site! We can all dream……)
Todd, I’m really interested in seeing your ROI for this. Also, I’m interested in whether solar can look good. Right now, our HOA won’t allow panels, and we don’t have a south-facing roof anyway (our house is almost perfectly situated east-west with a gable roof).
Another house nearby had panels on the roof – but they really (and I mean REALLY) let the place go. the panels were raised (likely to get a more southern exposure) and the whole thing was quite hideous. It would be neat to see some not-so-hideous installations.
Todd, I will see if I can dig up some pictures of flat plate collectors. I think if they can be installed without interrupting the roof line, they look a lot better, even if they are tilted up slightly. BTW, I calculated your roof pitch as ~40 degrees (10:12 pitch). Ideally the collectors want to be pitched between 43-50 degrees based on your latitude. You will only need an additional angle of 10 degrees, which by my calculations the tops of the panels would be 1.7 feet off of the roof (sin(10) x 10 = 1.7) for 50 degree tilt. Also, since your house is facing south of west, it looks like the garage roof might also be a good candidate for solar panels.
@ Paul – I never thought about the garage….that would make the installation so much easier. The piping could run down inside the garage and into the basement pretty easily. I’m not all that concerned about the additional 10 degrees. I’ve got a serious solar bug right now…until I find out how much this might cost ha ha.
If you are ready to go solar, find a local contractor near you at
http://www.successsolargroup.org/ for live consultations!