The phrase “solar energy” typically brings to mind shiny rooftop photovoltaics or expansive solar farms. But the truth is there’s much more to harnessing the sun’s power than solar cells, and sometimes in surprisingly simple ways. In fact, what might be most complicated for some is rethinking what you’d consider solar energy.
When you get right down to it, the most abundant solar energy is sunlight, and it happens to be free. It might sound trite, but the concept is paramount for those building new homes or renovating old ones. Passive solar home design, pretty much like it sounds, builds maximum solar use into every aspect of the home, from the walls to the windows to the floors, and minimizes the pesky summertime solar heat gain that makes us run our air conditioners.
And the key for maximizing a home’s passive solar potential, for many, is south-facing windows. Windows pointed toward the equator are able to capture sunlight more effectively without having the concentrated blasts of light and heat that east- and west-facing windows receive. In the winter, the natural sunlight lends natural heat, and so long as there is an overhang of some sort over the window, it won’t let in too much of the mid-day heat that makes us crank up the air.
This is something Paul Torcellini, manager for commercial buildings research at the National Renewable Energy Laboratory, considered when renovating his own 1920s home in Colorado.
“We added a sunroom to the south side to make the whole house more efficient,” he says. The sunroom is something of a vestibule around the front door, and it does double-duty, protecting the house from blasts of winter air while creating a naturally lit space that doesn’t use any temperature control.
In fact, Torcellini says that in many ways, the best way to get the sun’s energy into a home is with a sunroom — that most common of home additions — that can be blocked off from the rest of the house at night.
Products and DIY options
The very obvious low-hanging fruit in solar options is exterior lighting, and possibly for that very reason these fixtures are comparably priced to their traditional counterparts. The average Home Depot, Lowe’s and Ace Hardware are loaded with options, as is amazon.com. Brands such as Sol, Gama Sonic and Homebrite Solar specialize in creating solar-powered lighting, and many traditional brands have added solar-powered outdoor lighting to their offerings.
Skylights certainly let solar rays do their job to light up a home, but they also lend themselves to pesky side effects like solar heat gain, which leaves the average homeowner cranking up the air conditioner. An alternative that also makes for a slightly easier DIY project is a tubular daylighting device. These are characterized by a little dome that sticks up out of a roof, which allows the device to collect sunlight throughout the day. It then sends the light through a reflective tube that delivers it to a diffuser inside the home. Solatube specializes in these daylighting devices, and their product line includes an effect lens that allows for warmer and softer light.
When it comes to what modern man would consider a more traditional solar project, solar hot water heaters remain the best bet for a relatively fast return-on-investment. Keep in mind, though, that these are complex systems and not DIY-appropriate. Velux makes a variety of options, including a slick system that combines solar collectors with skylights that can open to allow natural ventilation.
Virtually all experts agree that until you’ve gotten any building to at least 50 or 60 percent energy savings (and more if you live somewhere where traditional energy is cheap), it doesn’t make much sense to invest in photovoltaics. But say you’ve gotten the insulation installed, the light bulbs switched to high efficiency models, the thermostat set to optimal temperatures, the windows and doors sealed up around the edges and the electronics switched off when you’re not around, this is the time to consider adding a solar array to your energy portfolio, and when you do, there are a few ways to recoup the expense.
Upfront costs can be recouped in the form of tax credits and rebate programs, which are being adopted by more and more states. Comprehensive information about energy savings programs, which can be filtered by specific items such as photovoltaics or solar thermal, can be found at energy.gov/savings. For by-state information, visit DSIRE Solar, which includes information about policy in addition to residential and commercial programs.
If the array on your house is really pumping out energy, some utilities also have buyback programs. Georgia Power, for instance, currently purchases solar energy at 17 cents per kilowatt hour. The company also has a green energy program in which customers pay a $5 premium on their monthly bill for a 100 kilowatt-hour block of green energy, half of which is solar. Although photovoltaics have come a long way over the years and ongoing innovation is expected to bring the price down, for those looking to really use solar energy in an affordable way right now, paying a premium in programs like this might prove the most cost-effective option.