Homeowners and builders are going green to reduce heating and cooling costs and do their part to preserve the environment, and a growing cluster of Merrimack Valley companies is helping them do it.
One Lawrence firm builds devices that convert the sun's rays to useable electricity, while another makes extremely energy-efficient housing.
A company in North Andover provides one-stop shopping to residential and commercial customers looking to reduce energy bills, while another is helping lessen the carbon footprint of New York City skyscrapers.
And a New Hampshire builder is using cutting-edge technology to reduce energy use in a subdivision in Methuen.
The Merrimack Valley Economic Development Council has identified at least local 16 companies involved in environmental or green technology and is working to attract more of them to the region, council President Robert Halpin said.
"This is a small but fast-growing segment of the economy," he said. "Nationwide, it's growing twice as fast as the rest of the economy."
Here's a look at five of the eco-friendly companies:
Nexamp Inc.: A Prius on the roof
At Osgood Landing in North Andover, an enormous rooftop solar array helps meet the power needs of the former Lucent Technologies plant, which is being converted to a mix of commercial, retail and light manufacturing space.
The company that installed the array is Nexamp Inc. of North Andover, formerly NexGen Energy Solutions.
Company president Dan Leary started the solar installation company two years ago and was joined by North Andover High School classmate Will Thompson. Since then, they have ridden the wave of interest in all things "green" to new offices, a 15-person staff and a host of clients.
The company also does work on geothermal, wind and micro-hydro projects.
"There are hundreds of different types of products out there," Leary said. "We try to get our customers the one that make the most sense to them."
One satisfied local customer is Girish Rao of Andover, who hired Nexamp two years ago to install solar electric and hot-water panels on the roof of his house on Highland Road. Rao was the first homeowner in Andover to get a permit for a grid-connected solar array.
His 24 photovoltaic electric panels and three solar hot-water panels provide 70 percent of his family's energy and hot water year-round, Rao said on a recent tour of his home.
From May to September, he said, the array supplies more energy than he can use. "That's when I sell it back to the grid," he said. The grid buys excess power from homeowners and businesses that generate their own power.
In winter, when the sun's not as high in the sky, he pays just $20 to $30 a month for electricity, he said.
Rao is also saving about $600 a year on oil because he doesn't depend on his furnace to heat as much water for him, his wife and their young daughter.
Despite the high upfront cost of the array — about $21,000 — "this was a no-brainer," he said.
State and federal tax credits and other incentives made it worthwhile, with a payback period of about 10 years.
"I call it my Toyota Prius on the roof," joked Rao.
Solectria Renewables: From solar cars to solar homes
James and Anita Worden founded Solectria Corp. in 1989 to produce solar-powered cars but five years ago switched gears to focus on solar inverters for residential and commercial use, changing the company name to Solectria Renewables.
Inverters are devices that convert the energy from solar panels into useable electricity. Solectria's inverters were used by Nexamp for the Osgood Landing array.
Solectria started its new life with about 3,000 square feet of space in the 360 Merrimack St. building owned by Sal Lupoli. Now it occupies 5,000 square feet and the Wordens are looking for more.
Solectria employ 15 people full-time while dozens more work for companies that supply Solectria with products needed to make the inverters.
"The economy is generally in tough shape, but this is one small thing to help it," said James Worden, 40. "We are booming."
Solectria has clients all over the country, but "California is the biggest market," Worden said.
The highest rooftop solar array on the planet is at 45 Rockefeller Center, and it uses Solectria's inverters to harness solar power for the 45-story building in Manhattan. Power from the inverters also lit up the famous Rockefeller Center Christmas tree last year.
ECM Energy: Skyscrapers turning green
Since 2003, ECM Energy Management Services of North Andover has been advising commercial clients like Time-Warner and Morgan Stanley on ways to reduce the carbon footprint of their buildings, many of them skyscrapers in the New York metro area.
"People are looking to save money," company president Eugene Garcia said, "but they are also concerned about the environment."
He uses a combination of tools to help his customers do that, noting, "a kilowatt not used is the best or greenest kilowatt."
Among the solutions are solar installations and thermal storage devices, which make ice at night when power is cheapest then use that ice to cool the building during the day.
But ECM also takes other, less glamorous steps for clients, such as helping them improve the operation of their buildings by putting lights on timers or simply buying more energy-efficient appliances.
"There are a whole bunch of things you can do," Garcia said, adding that big savings can also come from direct negotiations with the wholesale energy market to purchase energy. "You cut out the middle man and you can save 5 to 10 percent on your energy bills."
PowerHouse Enterprises: New homes unplugged
PowerHouse Enterprises of Lawrence addresses the needs of both homeowners and businesses, using techniques and materials that almost guarantee that energy bills will be low.
The 60 Island St. company builds and designs single-family homes and multi-family complexes and also offers its own "PowerPods," nearly self-contained structures that can go "off grid," with no need for outside sources of energy.
A home the company built on Market Street in Lawrence uses the latest in green building technology, from the recycled products in the floor joists to the solar panels on the roof, cutting heating and electric bills to around $50 or $60 a month, said Quincy Vale, president of the company.
He said PowerHouse has also entered the consulting business for large industrial and commercial customers.
For example, PowerHouse has been working on a project that would put together a consortium of Lawrence mill building owners to enter a long-term electricity supply contract, thus bringing down the cost of electricity for everyone involved.
"We want to help people control their energy and utility costs," Vale said.
Pellegrino Construction: A model subdivision
Pellegrino Construction of Salem, N.H., is building a subdivision in Methuen that will serve as a research and development lab of sorts for energy-efficient homes.
The 31-lot project will incorporate three types of homes, one using traditional 2-by-4 construction, another 2-by-6 construction and a third style using insulated concrete and steel.
"You'll be able to see what the difference is (in energy efficiency) all in one area," said company president Robert Pellegrino.
What people will find, he said, is that the 2-by-6 construction is more energy-efficient than 2-by-4 construction. But the concrete and steel structures will "blow people away."
Those structures employ a design pioneered by his stepfather, Robert Lefevre, when he built a home in Kingston, N.H., that is cooled and heated using nothing but solar energy.
"There's no furnace in the house," Pellegrino said.
While the first phase of the development is done.— roads and infrastructure — the energy-efficient concrete and steel housing won't be built until next spring or summer.
Those homes will sell for around $500,000, about 15 percent more than the "stick built," 2-by-4 and 2-by-6 houses in the development.