Bob Brown was interviewed as a part of our virtual tour of homes powered with solar. Brown installed the system himself and wanted to share how he overcame obstacles and other details that might help a would-be solar installer.
Read Bob Brown’s profile and view photos and drone footage of his home.
Obstacle #1: Shade analysis
In order to qualify for (at the time) the New Hampshire incentives program, the Public Utilities Commission required a “shade analysis,” meaning they required some form of data that proves that you would not lose more than 80% of sun exposure during the average time of solar collection. I found this a bit perplexing because on fixed systems, (like mine) the angle of the panel determines the efficiency, which is just as important as the shade effect. In order to satisfy the State requirement, I had to prove:
- There were no trees blocking the sun exposure to the panels
- I had to prove sun exposure at the angle of the roof. (not the angle of the panels!)
So I drew a CAD model of my house showing shading of the roof at equinox, Summer and Winter, and displayed (in a graph and visual) the exposed reduction, or shaded by my chimney, which was quite small. You can see this effect in the (provided) shade analysis. This satisfied the State requirement. Strangely, they did not ask about panel angle, which has a big effect on efficiency.
Obstacle #2: The Public Utilities Commission
I had 32 panels that were rated at 320 watts each, so 320w times 32 panels comes to 10,240 watts. PUC would disqualify me for the incentive program if I did not remove 1 panel from the system, even though the system included an inverter that would not put out more than 9.95KwH max, regardless of the number of panels. They were going by panel potential, not the actual output of the system. When I read the specifications of the requirement, it did not specify panel potential, but actual KwH output of the system. I had a bit of discussion with Jon Osgood of the PUC, but they were steadfast in keeping with their requirement. So to qualify, I had to remove a panel, photograph the system as it stood, (with 31 panels instead of 32) and send it to PUC. Once I received PUC approval, I put the panel back on the roof. In the end, the system (given all angles, losses, etc.) with 32 panels generates a pretty solid 8KwH on average during the summer months. I average a modest 1.4KwH during winter months (late November through February) due to the 28 degree horizon of the sun.
Obstacle #3: The City of Keene
The City of Keene planning and safety department required proof that the weight of the panels was safe to put on the roof. At the time, I had two layers of asphalt shingles on the roof, so I used the weight of the shingles, subtracted the weight of one layer (because I was replacing the entire roof with one new layer of asphalt shingles) and came up about 500 pounds less in weight after adding the solar panels. Beyond that, they wanted to know the roof construction specifications (beam construction and layout) to ensure everything was within established tolerances before issuing the building permit.
This only became an obstacle for me because I had to review building codes and photograph / show proof of what was contained at my residence.
This project took about 4 1/2 months total, from start to commissioning. The rest of this project was basic research, where to find parts, what space I had to work with on the roof, schematic, documentation and construction.
It was a satisfying challenge to prove that obtaining solar power is not only great for the environment, it’s also financially rewarding as well, and in short order if you do it yourself. You don’t need a College degree to do this. My system has already paid for itself in energy savings alone in the five years I’ve owned it.