As a nine-year volunteer for SolarYpsi, a grassroots solar advocacy organization, I’ve helped design and install about a dozen grid-tied solar-electric systems in Ypsilanti, Michigan. Ironically, until recently, my own home’s rooftop had remained without photovoltaic (PV) modules.
I often dreamed of solar power for our family’s home, but the high initial system cost, the home’s orientation, and its location in the historic district seemed like high hurdles. The front of our 122-year-old Victorian home’s gable end faces south with three large maple trees shading it, and its roofs face east and west. The backyard is filled with trees and a garden, so a ground- or pole-mounted system was not an option.
Then there was the cost of the system itself. In SolarYpsi’s early years, PV systems cost $7 to $11 per installed watt—and that was with using an all-volunteer labor force. My interest was renewed after I calculated the installation cost for our latest PV project at the Ypsilanti Food Cooperative. Using volunteer labor and $0.78-per-watt Evergreen PV modules from a bankruptcy sale, SolarYpsi was able to install the system for $3 per watt. This was the first time PV power seemed it might be affordable for non-ideal orientations or locations. More surprising was that the $0.78 per watt was not an anomaly. Later that summer, closeout UniSolar modules were available for $0.50 per watt after the company’s bankruptcy. That motivated me to start searching the Internet regularly, and I soon discovered that $1-per-watt PV modules were becoming common.
Three occurrences inspired me to revisit the idea of putting a PV system on our house. Our retired neighbor, Larry, was installing a PV system at his house, and he was able to self-install his system for less than $2 per watt (before incentives). He took a creative approach to the mount, purchasing aluminum channel for the rails at a scrapyard for a fraction of the cost of new rails. He also saved some money by fabricating his own top clamps and roof mounts. Note that creating custom racks can save some money upfront, but the responsibility of making sure all of the appropriate engineering calculations have been considered and implemented falls on the system owner (see Web Extras for an article on racking options for roof-mounted PV systems).
Then, a new PV installation company, Sade Power, established itself in southeast Michigan and was advertising batteryless grid-tied PV installations for $2.50 per watt. Another local solar contractor—AJ Leo—was also installing systems for about $3 per watt using Michigan-made PV modules and inverters.