Solar power offers little hedge against grid problems
Solar power offers little hedge against grid problems
Monday, November 14, 2011
Rebecca Waldo remembers the frantic phone calls from her and her husband's many Waldo Renewable Electric solar customers after Tropical Storm Irene blacked out much of the state: "What can I do? What can I do?"
For most, the answer was suffer without power like everyone else.
Irene and the freak October snowstorm each were followed by days of brilliant sunshine, but all most folks with solar systems in blacked-out areas could do was look at them glisten in the light and imagine the power they could have been making.
Solar systems typically work in conjunction with the grid, feeding power to it when the system is making more than a building can use, and taking power from it when the system cannot generate enough or at night when it generates nothing. System owners pay for the difference between the two, a practice called net metering. But unless you have a battery storage system, when grid power goes out -- you go with it.
Companies like Waldo report their phones have been ringing off the hook with system owners curious about battery back-ups and new customers in search of solar systems with battery back-ups -- a request most installers say they rarely, if ever, heard prior to Irene.
But rather than a boon for solar companies with potential business in both back-up systems and solar in general, the truth more-often-than-not is that battery back-up may not be particularly useful and, due to a quirk in the state's solar incentive programs, this may not be an optimal time to buy one.
"We don't necessarily recommend the battery back up system," said Waldo, echoing a sentiment expressed by nearly every installer contacted. "We do them here and there; when it comes own to it, it's what the customer wants. We just usually try to recommend to customers not to do it."
Chris Lenda of Aegis Electrical Systems in Branford has installed battery backups, mainly in off-grid systems on the Thimble Islands, where standard power is unavailable. He, too, has been getting calls lately.
"Most of our customers, we tell them flat out it doesn't make any economic sense to put in a battery back up in conjunction with a solar system," he said.
Installers and others cite multiple issues, starting with price. They are expensive. Prices vary with the size of the system, but more than $10,000 is good place to start; some installers figure an additional 40 percent on the system price. Regardless, it's likely significantly more than a standard back-up generator, and a whole lot less reliable.
Ron French, who recently merged his Connecticut company, Alteris Renewables, with the Colorado based Real Goods Solar, said they've gotten loads of calls since the storms, but have no plans to reverse their decision to discontinue installing them due to limited demand. "The other issue for us that if power is out, we become the power provider for the customer which carries a service obligation which we're not structured to support," he said.
Others note the maintenance batteries require, and the less than earth-friendly lead acid in them.
"We are in the renewable business," said Anthony Coschigano who founded Mercury Solar Systems in Greenwich in 2006. "We don't want to promote the use of more carbon emitting fuels, but from a practical perspective, batteries are not very practical."
Unless the battery system is huge, it will only be able to run a limited number of things for a day or so, at which point the batteries will shut off to re-charge, leaving you in the dark until they do.
How long will that take?
Another day or so -- if it's summer, and the sun is out. If it's the dead of winter with short days, a re-charge could take several days. If it's a blizzard and there's a foot of snow on your panels, there's a shot your grid power will come back first.
Then there are a bunch of technical issues. The energy coming directly from a solar panel is direct current, DC, that requires an "inverter" to change it into usable alternating current, AC. But not all inverters are compatible with battery backup systems, so retrofitting a system with a storage battery may often require a new, and not inexpensive, inverter. Some of the newest solar technology, tiny inverters - called microinverters -- on the back of each panel, are not compatible with batteries.
Often a battery back-up system will require re-wiring the panels, yet another expense. And overall it will make your regular solar system less efficient because some of the power is diverted to charge the batteries.
Some battery systems may not qualify for the 30 percent federal tax credit available to people installing solar systems. In Connecticut, they are not eligible for funding under any incentive programs through the Clean Energy Finance and Investment Authority. Under current lease terms in the state's solar leasing program - which means homeowners don't actually own their solar equipment - batteries cannot be added.
Complicating the situation, the state's solar incentive programs are in transition to more sustainable funding models. With money nearly gone in the old programs, but the new ones unlikely to be in place until the first quarter of next year or later, it's not an ideal time for consumers to get the best solar incentives, leaving companies at something of a loss to capitalize on the interest in solar - with or without batter backups - since the storms.
And even CEFIA's Director of Renewable Energy Deployment, Dale Hedman, who has been overseeing the solar incentive programs, agrees batteries may not be worth it.
"Using an objective economic view - it just may be that you're better off getting a small gas generator," he said. But he added: "If you're conscious about your carbon footprint and all that stuff, you need to throw that into the equation."
Mike Trahan, executive director of the trade group Solar Connecticut has heard the negativity. While he doesn't deny the expense of batteries, he remembers the similar concerns about solar systems.
"The same questions were asked about solar power 10 years ago," he said. "It's a healthy discussion."
He believes the increased interest in solar backup batteries could kickstart that industry to become more affordable. "The same pressure on [photo-voltaic] module makers 10 years ago to drive down costs is the kind of pressure that's going to be put on battery makers to drive down their costs," he said.
Bruce Angeloszek of CT Electrical Services is one solar company owner that is bucking the trend to steer clear of battery backups. He said he had at least 25 to 30 calls for solar in the few days following the October snowstorm and that at least half of them requested battery backup.
Back-up systems can be effective and reliable, he said: "If you size the battery system to what you want o accomplish and how long want it. It all depends on the load. The best part of a battery system," he said. "No moving parts and the fuel is free."
Of course, he added: "You can't get mad at your batteries the way you can CL&P."