I contacted several different NABCEP-certified solar installers. I had a good idea of what the complete system would look like and what equipment was available, so this was kind of a test for the two I sought bids from.
I hired Four Winds Renewable Energy (FWRE) out of Arkport, New York, which was only a few minutes’ drive from our property. Not only had owner/installer Roy Butler been installing off-grid PV systems for decades, but he also lived off-grid. After Roy did a site survey, we took his proposal and tweaked it a little bit to arrive at our system design: a 4 kW PV system with a 740 Ah battery bank and a 6 kW backup generator. FWRE would order and install the equipment for about $30,000. New York state does not offer any rebates or tax incentives for off-grid systems, although we did qualify for the 30% federal tax credit.
To keep costs down, I took responsibility for hiring an excavator for the pole holes and the wiring trenches, repairing the yard after the trenching was finished, preparing the basement wall for mounting the balance-of-system components, and the rough AC wiring between the generator and the inverter. I was also responsible for selecting and installing the generator and its fuel supply—a propane Generac 6 kW EcoGen, which is the only generator designed and warranted for off-grid use with a renewable energy system.
We started the installation the first week of September. It probably would have taken less time to install if I hadn’t been there, but it was important to me to watch and learn as much as I could about the installation and how all of the components worked together.
Setting the two 6-inch, 21-foot-long steel poles for the pole-mounted system was a critical step. They had to be lifted into place with the backhoe and set in 24-inch, 6-foot-long concrete form tubes. Since the arrays presented a large surface area for wind loads, plenty of ballast was needed to keep them in place.
While the concrete was curing around the poles, we installed the BOS equipment. The inverter, charge controllers, battery box, and batteries were all wired, connections torqued, and parts labeled.
A couple of days later, the first array was installed and was charging the batteries. Our new system sounded like nothing—it was dead silent. No generator noise, just a dull hum from the battery box fan. A day or two later, the second array was online. The backup generator was delivered, and we installed that and wired it into the system for those stretches of little to no sun, and for enough energy to occasionally equalize the batteries (an intentional overcharging of the battery bank to remove imbalances between individual batteries).
The first thing we did was plug in our refrigerator. It’s funny how some things get taken for granted, like having a refrigerator instead of buying ice every day and living out of an ice chest, as we did before installing the PV system. I remember my wife saying that if all we could ever supply electricity to was the refrigerator, it would be OK with her.
By the last week in September, our new system was complete. There was still much to learn and do—understanding the technical and practical details of a whole new electrical supply system, tweaking the charge parameters to properly charge the batteries, and reminding the kids to turn off the lights! I pay special attention to the batteries, since they are the heart of the system and its most vulnerable part. To date, there have not been any major issues or problems. The array tilt was adjusted to an optimum angle for the winter and left there. I adjusted the array for the summer angle on April 1, and will readjust it again this fall.