Solar Panel Saga Ends

It's been over a month since my last post and I finally have something significant to report.  After all kinds of paperwork problems and a 5-month delay, the photovoltaic (PV) system was finally installed!  Although we are heading into the shortest days of the year, the weather was spectacular for the installation.  After two days of work, the system went live and we were generating electricity!

Solar panels being installed (Click image for more photos.)

The first stage of the installation was to measure and cut the supporting rails that the panels would sit on. These rails were then secured to the roof with screws. That means a whole lot of penetrations to the roof. Yikes! Holes in the roof! These penetrations are sealed with silicon to make them waterproof and prevent roof leaks. I hope they know what they're doing because I sure don't like the idea of adding holes to the roof.

Once the rails are in place and the sealer has dried, they run cable from the roof through the attic and down into the basement. During construction we installed an electrical chase specifically for this purpose. After completing the wiring, they starting installing the panels. I was surprised by how lightweight and tough the panels were. Each weighed about 35 pounds (the weight is mostly the support structure) and they are designed to withstand hail that is one-inch in diameter. The actual installation of the panels went fairly quickly. They are carried up one at a time and bolted to the rails. It takes only a few minutes per panel to install them.

Installing a panel! (Click image for more photos.)

Meanwhile, the inverter and meter are installed in the basement. The inverter converts the direct-current (DC) voltage into alternating-current (AC) so that it can be fed into the house and onto "the grid." The 26 panels are connected in a series-parallel connection with two 13-panel series groups connected in parallel. Each series group produces about 400 Volts. I'm not familiar with how the inverter works, but at its core is a coil of copper wire that weighs well over 100 pounds. I didn't expect the inverter to be quite as substantial a device as it is.

Inverter and meter wiring (Click image for more photos.)

In addition to the wiring in the basement, they are required to install two shutoff switches outside the house, one for the DC and one for the AC. Once everything was installed, the system was turned on and voila, we were generating electricity (very little because it was early in the morning). Unfortunately, the system must be shut down until it gets inspected. Of course, once the system is turned on for good, we're entering the worst time of the year for PV electricity production. The panels themselves are at their best in terms of efficiency in the cold weather, but the days are getting very short. Nevertheless, it's exciting to think that we will soon be producing much, and hopefully all, of our electricity on an annual basis.

System is on! (Click image for more photos.)

At some point, I plan on investing in a metering system that allows us to post real-time electricity usage and production via the web. Until then, I'll give occasional updates on how much energy we are producing.