Case Study #3
Wayne Allen’s house, set on the edge of a sloping field encircled by woods, looks like a typical American home. If you were paying attention, you might notice that there are no power lines running to the house. That’s because Wayne’s house is powered by a 540-watt PV array, located across the stream on the south side of the house.
Underground cables carry power from the shed where the batteries are stored into the house, preserving the view of the land. “This is such a beautiful place we have here,” commented Wayne. “When my wife and I moved out here, we didn’t want power lines ruining the view, so we asked the power company if they would bury the power lines. They refused to work with us, so we decided to put in a PV system instead.”
The Allen’s PV system uses two 120-watt and four 75-watt PV panels mounted on two separate posts. One of the mounts has a tracking mechanism that follows the sun through the sky, enabling the panels to generate more power. The other mount is fixed facing due south. The system includes 16 golf cart batteries (Trojan T-105) and an inverter which provides AC power to the house. A back-up generator recharges the batteries when they get low, mainly during extended periods of cloudy weather in the winter. Wayne says he’s never needed to recharge the batteries in the summertime, but occasionally it’s needed in the winter. They also use the generator periodically in the summer to directly operate their air conditioner.
Wayne says he doesn’t feel like he’s sacrificing any comforts or conveniences to be living off-the-grid with a solar system. “We have all of the appliances people typically have,” he said. “My wife and I watch TV and use the computer quite a bit. We have enough lighting and use ceiling fans. The PV system has met our needs just fine.” They also use the PV system to pump water from their cistern. The PV system is supplemented by a propane refrigerator, water heater, and clothes dryer.
The Allen’s have been very satisfied with the PV system since they installed it in 1999. “It’s actually been less bothersome than I had expected,” said Wayne. Adding water to the batteries a couple times per year has been about all the maintenance the system has required. Their batteries have begun to age, however, and are not holding a charge as long as they used to. They expect to replace the batteries in the near future.The installed cost for the Allen’s PV system was less than $8,000, including labor and equipment. Wayne did most of the work himself, but hired an experienced PV installer (Joshua Bills) to help with some of the technical details.
They are expecting to install an additional 360-watts of PV power in the coming year, and hope to some day install a solar water heater, as well.