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How to install solar power and save

It’s never been easier or more financially appealing.

Philip Hackett

Thomas and Margaret Hall of Quincy have almost twice the house they did in 2009 but less than half the utility bills. “The renovation started because we needed another bathroom,” says Thomas, who works in technical sales at IBM. But the scope of the project quickly expanded, and the couple ended up adding a floor and a half to their 1903 bungalow, just about doubling its square footage. “During the construction we’d super-insulated the house, making it extra-extra efficient, so we decided as committed environmentalists now was the time to add solar. We thought, ‘We’ll never do this again; let’s do it right.’ ” They’re glad they did, since their winter utility bills have gone from around $500 a month to a mere $110 or so, despite more than 1,500 square feet of additional space. “That includes electric and gas,” Thomas points out.

By now everyone knows that solar power can save homeowners big money on utility bills. But doesn’t it also cost big money to install? It doesn’t have to. (Read on.) Isn’t there a big learning curve? Nope. “You don’t need to know anything,” Thomas says. “It just runs.” And does it even work during dreary New England winters? Yes, as long as you have land or a roof that’s not shaded by trees or other buildings and is oriented correctly (south-facing is ideal but not mandatory). “Even snow doesn’t matter if your panels have a steep angle,” says Henry K. Vandermark, founder and president of Solar Wave Energy in Cambridge. “It just slides right off them.”


So the easy questions are out of the way. And the more complicated aspects of going solar, it turns out, aren’t so difficult, either, once you break them down.

Two Ways to Go Solar

There are two kinds of solar power: photovoltaic, or PV, which produces electricity, and thermal, which warms tap water and can be used for heating in homes with radiant floors. Both systems can be erected on land or atop roofs; roof-mounted panels may require minor structural improvements — such as sistered joists in the attic — to help your roof bear their weight.


The Hall family was lucky; they were able to have both kinds installed when they did their renovation. Many New Englanders will have to make compromises, as each system needs a significant amount of roof or yard space. “Usually there’s a constraint,” says Paul Lyons, founder and president of Zapotec Energy in Cambridge. “Say you have a 2,500-square-foot house. It’s probably two stories, so you have maybe 1,200 square feet on one story. The roof might be 1,400 square feet, and half of it faces north, so you’re left with only 700 square feet facing south.” Many metro-area homes have even less.

While thermal doesn’t work well with hot-water radiators or baseboards, it brings a nice warmth to rooms with radiant floors. And it can save the most in utility costs in houses that currently use oil for heating. “If you use a lot of oil and have limited roof space and radiant heat in the house,” says Erica Boyle, president and owner of RESSolar in Cohasset, “thermal has a phenomenal payback. If you use natural gas and have more roof space, PV might have a better payback. But I really want to stress that there’s a system out there for almost everyone.”


And she does mean everyone. Even if you lack sufficient roof space or rent your home, you can buy a share in a solar garden, also known as community shared solar. These energy shares use net metering, in which solar panels are connected to public utility power grids, allowing them to transfer their extra power onto the grids in exchange for credits on traditional utility bills. “You buy a share of a solar garden that is located in the same utility area that you’re in,” says Brian Greenfield, chief operating officer of Next Step Living, an energy-efficiency company in the Seaport District. “You buy a certain number of panels, and as they produce power, your electric bill gets credited in exactly the same way as if it’s on your roof.”

Panels in a solar garden cost about $1,300 each, and the average household needs 16 to 18 to cover its electricity use in full. “You can pay upfront or we can help you access financing,” Greenfield says, adding that those who buy into solar gardens — which are being built all over the state — are even eligible for state rebates and in some cases tax credits. “You save quite a bit if you buy into solar. Over time it’s a roughly 7 to 10 percent annual return.” That’s way better than a savings account, and you’re banking good karma at the same time.

Thermal How-to

The installation of solar water heating is a little more complicated than that of photovoltaic systems, mainly because it requires plumbing. However, thermal panels need less square footage. The maintenance on thermal panels, as with photovoltaic, is virtually nil.


If you want to keep your existing water tank you can, but you’ll have to install a second one for the thermal system to use; it will act as a pre-heater, so that the water going into your regular tank will already be hot. “Most people have small water heaters, because if you’re heating with gas, oil, or traditional electric, you don’t want to keep a lot of water sitting there being heated all day for the few minutes you’ll use it,” says Boyle. “With solar you want 120 gallons, or 80 at bare minimum — enough for a day or two, because in New England it could be cloudy tomorrow.”

If your tank is shot anyway, you can get a single new tank as part of the system; the best of these is made of stainless steel and has a lifetime warranty. Rather than keeping your solar tank at 120 degrees, as energy-efficiency experts recommend for traditional systems, you’ll want to keep it at 160 degrees. “The water stays hot because the tanks are so well insulated now that there’s very little standby heat loss,” says Boyle. “And it goes out to the house through a mixing valve, so you end up with more gallons than you can use.”

Photovoltaic How-to

Photovoltaic panels (technically called modules) have a series of solar cells on them that, with the help of the sun, produce direct current (DC) electricity. The panels are connected to one another and, usually, to an inverter in the basement or at the side of the house (sometimes micro-inverters are right on the panels). The inverter changes the DC electricity to AC, or alternating current, which is used in most homes. The inverter has an “input” side that’s DC and an “output” side that’s AC; the “output” side is wired to your existing electrical panel, where the electricity generated can be used to power your house or transmitted to the grid for credit.


As with thermal panels, photovoltaic panels can withstand winds of up to 150 miles per hour and golfball-size hail. If you have a service contract, your installer will probably put a data logger on the system that sends an alarm to his or her computer if there’s a problem, but make sure you’re not paying for cleaning — the rain will take care of that — or annual maintenance, which is not necessary. Barring falling meteors, stray baseballs, sinkholes, serious earthquakes, or icy hose water on a hot day, the tempered glass shouldn’t crack. And if it does, says Ben Mayer, vice president of marketing and director of residential projects at SunBug Solar, an installation company in Arlington, “even the less expensive PV panels have a 25-year warranty. Inverters have 10- or 12-year warranties, and for $400 to $700 more, you can get an extended 25-year warranty on inverters, too. The hassles are essentially zero.” Make sure your warranty includes on-site repair or replacement, and that it’s backed by a third party in case your installer should go out of business.

Weighing the Costs

If your own home lacks sufficient roof space or you rent, you can turn to a local solar garden.istockphoto/iStock

The typical cost of a thermal-only system ranges from $8,000 to $15,000. The price of photovoltaic is down considerably even in the past few years: Today a 7,000-watt system, which could power an average house and requires 700 square feet of roof space, would run around $30,000; in the city — since the roofs tend to be smaller and have more dormers — a more typical size would be 5,000 watts, at a cost of around $25,000.

The good news is that for both kinds of systems, the costs are offset considerably by the state’s green energy-friendly policies. The financial incentives for installing a photovoltaic system, for example, are considerable:

>  For the next six months, the Massachusetts Clean Energy Center, a quasi state agency, will continue its rebate program, which averages around $1,250 for a residential installation — more for low- and moderate-income consumers.

>   There’s a state tax credit of 15 percent of the gross cost of the system, capped at $1,000.

>   There’s an uncapped federal tax credit of 30 percent of gross cost. On an average $25,000 5,000-watt system, these first three incentives alone bring your cost down to a little more than $15,000.

>   SRECs, or solar renewable energy certificates, are a Massachusetts Department of Energy Resources incentive that reward consumers for every megawatt hour generated in the first 10 years of installation. SRECs change over time and are determined by a somewhat complex formula, but Mayer estimates they can add up to $1,000 to $2,000 a year for the first couple of years.

> Then there’s the hundreds of dollars a year, depending on the size of your system and your energy usage, in utility savings. Together, these money-savers mean the out-of-pocket cost of your new solar system could be recovered in three to 12 years.

Sun power might well enhance your property’s value, too. A 2013 study by the Lawrence Berkeley National Laboratory in Berkeley, California, found that solar-powered homes sell for an average of almost $25,000 more than those with traditional power sources. Only houses in California were studied, but according to its author, staff research associate Ben Hoen, “if the system is owned by the homeowner and is relatively new, it’s reasonable to assume there would be a premium in Massachusetts, too.” The level of the premium, he adds, would depend on specific market factors, such as the cost of energy in the area. That’s good news for New Englanders, since according to the US Energy Information Administration in Washington, D.C., the region is the most expensive region for electricity in the country outside of Alaska and Hawaii, at 18.29 cents per kilowatt hour in April — 5.82 cents more than the nation as a whole.

How to Pay

Even with all those perks, the initial outlay for solar generation can pinch the budget. There are two ways to shoulder the burden: owning and leasing.

If you meet certain income guidelines and wish to buy a thermal system, the Mass Save Residential HEAT Loan Program provides no-interest loans of up to $25,000 over as much as seven years. Photovoltaic systems are often financed privately. If you don’t have enough value in your house to get an equity loan, many solar installers offer financing through banks. For qualifying customers, for example, Brightstar Solar in Marlborough has 12-year loans with 1.99 or 2.99 percent fixed interest rates and no down payment.

Another option is to lease your system, either with a traditional lease or a power purchase agreement. With a power purchase agreement, a company like Sunrun, which is headquartered in San Francisco and pioneered this kind of arrangement in 2007, installs a solar system on your property at little or no cost to you, selling you the power generated at a fixed rate that’s typically slightly lower than that of the local utility. After the lease ends, you can renew or in some cases buy your system at a reduced cost that takes into account depreciation. And if you want to sell your house, you could even transfer the lease to the buyers if they qualify for its terms.

The Halls financed the photovoltaic side of their solar system with a power purchase agreement. “Your [cost per kilowatt] is locked in for 18 or 20 years,” Thomas Hall says. “So in the first and second years you don’t look very smart but by the time you get to 18 years, electricity might be $1 a kilowatt. Who knew gas was going to be $4 a gallon, right? I [once] bought gas for 29 cents a gallon.”

People have their own reasons for preferring to lease, just as they may choose renting an apartment over buying a condo. But Mayer of SunBug Solar says that “while they are getting something wonderful, they’re losing something enormous.” A consulting group did a 2013 study for the state’s Department of Energy Resources that assessed the economic impact for both the homeowner and the Massachusetts economy in the difference between ownership and a power purchase agreement. It found that homeowners receive a tenth of the benefit of the leasing company, which gets the rebates, tax deductions, and SRECs on the system on your roof — about $1,200 vs. $11,000 over 20 years. “It’s for people who have wonderful roofs, so the production ratio is very high,” Mayer continues. “That helps the lease economics — you get a better rate. But you also have to understand you’re signing a 20-year legal agreement with a corporation. It’s increasingly framed as what you’re getting, but nobody mentions what you’re giving up.”

On the upside, though, he points out that if so many third-party companies are jumping onto the solar bandwagon, solar energy is here to stay. “If I’m Sunrun,” he says, “I have lawyers, financial analysts, technical officers — enormous resources to see if I want to take the risk to own thousands of solar systems on individual homes across the country. No amount of good, safe research by a homeowner comes close to their research, and they’re the ones saying, ‘Yeah, we’ll put this on your roof for 20 years.’ What could be more reassurance?”



“There’s a lot of consolidation in this industry,” says Thomas Hall, who had solar power installed on his Quincy roof in 2010. “The smaller companies get bought up, so do your due diligence. Find out how long a company has been in business, get references, and find out how many installations they have done. You want a company that’s done 50 or 100 of these, not two.”

As with any other large home improvement, talk with more than one provider. Start at masscec.com/content/finding-solar-pv-installer, where you can find a list of questions to help you choose an installer; for example, ask whether the work will be subcontracted out. From this website you can also download a list of contractors, along with their installation costs and approved rebates.



While wind turbines erected on the ground are an option if you have enough acreage and the right site, it’s going to be awhile before they become common atop roofs. The existing technology is still a little shaky — literally, since the motion of the blades causes vibrations too strong for most residential roofs to withstand. Still, says Erica Boyle, owner of RESSolar in Cohasset, “I think with enough research and development, rooftop options will be viable in the future.”

More coverage:

- Borrego Solar aids solar power boom in Mass.

- Bright future for solar roads?

- More from the Magazine

Elizabeth Gehrman is a frequent contributor to the Globe Magazine. Send comments to magazine@globe.com.