The past weeks have seen dramatic and wonderful changes at the Folly. Not only is there wallboard on all the walls throughout the house, but the interior has been primed for final painting. But…but, one needs to look up to see the most telling changes. The photovoltaic (PV) panels have been installed on the roof and Folly is generating electricity!!
Like most complex projects, this was done in stages. The cement roofing tiles were delivered and set in place on the roof sections facing north and west, that is, on those areas that would not have PV panels. Then the PV panels were delivered to the site.
A feature of this project which excites me is that the opportunity to teach local tradesman how to work with new technology. So on installation day, Folly was really a classroom, a hands-on project for the electricians and roofers. Manny, the rep of the company that makes the PV panels, was their teacher. This system is called Building Integrated Photo Voltaic (BIPV) and has many benefits for the homeowner. The panels are flat to the roof (rather than being raised above the roof) and blend into the roofline so that they are nearly invisible from the ground. They are slightly different in size in that each PV panel is as long as four cement tiles. In addition, Folly’s roof tiles are dark grey to match the PV as closely as possible.
There was some discussion as to the best installation method. After all, any house in a hurricane zone runs the risk of having a 140 mph breeze blow roof tiles up and sailing across the landscape. That is not a good neighbor policy. In the end, the most conservative option was used (here it’s called the “belt and suspenders”). The PV panels are held down by 1) a band of tar, 2) four lines of foam “glue” and 3) two screws.
The electricians found that this was not as technically challenging as they had expected. These panels are connected in short series (like strings of Christmas lights) before connecting to the main line. A lot of time was spent in checking that each panel could produce power and then that the entire line was “hot”. Very careful work. Fortunately, the cloudy sky that day made working conditions comfortable on the roof, and, surprisingly, even in that less-than-optimal state the panels produced electricity.
The final step is to install inverters that will make Folly’s solar generated power available to our electric company and usable for our appliances. PV panels produce direct current while we in the USA use alternating current. When the inverters are installed next week we can watch the electric meter spin backwards as we sell electricity to the grid!
All in all it was a momentous day for Folly! Please check out the video for a closer look.
