My husband and I never thought we could heat our Chicago condominium unit with solar energy—we don’t even own exclusive roof rights on our building. But we noticed the roof had space for solar panels and good solar exposure, and this potential was completely untapped. Our condominium unit is now equipped with a 1.7-kW solar system that generates more than enough power for our unit. Here’s how we did it.
Approaching the condominium board of directors was easier than I thought it would be. We made some promises to help deter the board’s concerns:
■ We wouldn't penetrate the roof membrane. We used an adjustable, ballasted pan system, weighed down by cement blocks, to mount the panels. This allows the panels to be moved for roof maintenance and to adjust their angle by 20 degrees depending on the sun’s seasonal angle.
■ All wiring runs down the back of the building and follows existing conduits whenever possible, so it doesn’t change the building exterior’s aesthetics.
■ Only the AC disconnect was mounted on the building exterior. This is required by our local utility, to ensure the disconnect is accessible during emergencies or to perform repairs. We found a place for the inverter and the DC disconnect inside our unit.
The interior solar components had to feed into our electric panel, which is in our kitchen. But we didn’t want the kitchen to look like a web of conduit with visible solar equipment mounted on the walls.
Our solution was to install additional cabinets and run the conduit along the top, where it’s not visible. We put the inverter inside a cabinet and removed the top and bottom to allow air circulation (it’s important that the inverter does not overheat). The kitchen’s solar components are totally hidden, and the cabinet mitigates noise from the inverter.
Energy efficiency and solar system size
We reduced the size (and cost) of our solar system by first reducing the amount of electricity we consume. We purchased energy-efficient appliances and installed efficient light bulbs. We frequently line-dry clothes in our laundry room, which also naturally adds humidity to dry indoor air. We use the air conditioner modestly.
We also conducted a home energy audit using a home monitoring device. We found that our television, VCR, DVD player and stereo all constantly drained electricity, even when they were turned off. Now we use power strips to turn them off completely when not in use.
To determine what size solar system we would need, we calculated our annual energy use. The National Renewable Energy Laboratory has a free online program called PV Watts that considers system efficiency, local climate and available daylight to estimate any given solar system’s output. We then matched the system’s estimated output with our electricity consumption over the past year.
Financial analysis and energy output
We received the Illinois state rebate, which paid 30 percent of the solar system’s cost, as well as a $2,000 federal tax credit. The paperwork was simple, and we got our checks quickly. The two incentives reduced the solar system cost by nearly 50 percent.
Illinois recently passed net-metering legislation, making it one of 42 states that purchase surplus electricity generated from solar systems. We generate surplus by day and take electricity from the grid at night. My neighbors like knowing that a portion of their daytime electricity may have been generated on their own roof.
We expect the solar system to increase the resale value of our condominium. Along with several other eco-friendly improvements, the solar system will help us market our home as a “green condo” when the time comes to sell.