LightWave Installs TN’s Largest Residential PV System
SOMERVILLE, Tenn. — It was a flat patch of open ground where a different owner might have installed a pool, but Steve Denton had other ideas.
Long a believer in conservation and clean energy, he installed an expansive array of solar panels — no fewer than 72 of them, in fact. Mounted on poles, they tilt at a 30-degree angle toward the southern sky at his home near Somerville.
Photo by Alan Spearman
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“Obviously, it wouldn’t work in Germantown,” he joked as he stood next to the imposing twin structures — each with 36 panels — that are 52 feet long, 11 feet wide and supported by five poles each.
Denton’s 16.5-kilowatt photovoltaic array is believed to be the largest residential solar-energy system in Tennessee, said Gary Wolf, of Nashville-based LightWave Solar Electric, the largest solar design and installation firm in the state. It’s slightly larger than one in Middle Tennessee owned by Sheryl Crow, the Grammy Award-winning artist.
For Denton, 56, an aircraft mechanic who works at the Jackson, Tenn., airport, the allure of clean energy and conservation has been growing steadily.
He and his wife Doris long have employed passive solar energy to help warm their homes. They also hang their clothes out instead of using a dryer and don’t bother with an automatic dishwasher. Their walls are stuffed with 6-inch-thick foam insulation, making the home a veritable igloo.
“The interest for me has been saving energy,” Denton said.
He initially studied the idea of installing wind turbines. But over the course of the year, the winds across much of West Tennessee average a scant 8.8 mph — well below the 12 mph need to make wind energy practical.
The solar array, which will save an estimated 370 tons of carbon dioxide emissions over the next 25 years, was designed to produce about as much energy as the Dentons use.
Through its Generation Partners program, which is designed to encourage clean energy, Tennessee Valley Authority buys the solar power produced by Denton for 22 cents per kilowatt-hour. That’s 12 cents more than what Denton and other area residential customers pay for electricity sold by utilities.
A check of his meters on a recent evening showed his system had produced 439 kilowatt-hours over the previous eight days, compared to the 541 kilowatt-hours consumed by the household. Three days of clouds and rain had curtailed power generation.
“I tell people this is just like your (cell phone) rollover minutes,” he said. “You build up a few minutes on a slow month and use them on a fast month.”
In the event of a utility power outage, the solar energy charges batteries that Denton can use for power at his home.
Although renewable energy sources still account for a tiny fraction of the power distributed by TVA, Denton is one of the more than 80 participants in the Generation Partners program who combine to produce 808 kilowatts for the agency. TVA also has built its own solar and wind power facilities.
Denton declined to say how much he paid for the system, but according to industry officials the average cost for solar power is $7-9 per watt of generating capacity. That means systems the size of Denton’s — at 16,500 watts — often run at least $115,000.
“I could say it’s a whole lot cheaper to save the electricity than it is to generate it,” Denton said.
Still, solar industry officials say the systems generally pay for themselves in 12-15 years.
Denton and other residents who install solar energy are eligible for incentives that include $1,000 through TVA’s distributors to offset installation costs. They also get a federal tax credit worth 30 percent of the system’s cost.
Yet Wolf, with LightWave Solar, said the residential market is being held back by a lack somewhat because Tennessee doesn’t offer the grants and other support that other states provide. The state does provide special incentives for commercial solar projects.
“There’s a lot of interest,” Wolf said. “We get a lot of calls, but we don’t get that many people doing it.”
Still, Tennessee has a vast untapped potential for solar energy, Wolf said.
“The two leading countries in the world in solar energy are Germany and Japan,” he said. “Tennessee gets more sun than either one of them.”