Because incentive programs and pricing continue to evolve, it’s worth comparing more than one source before deciding. The Terawatt Platform connects homeowners with vetted local installers and walks through system sizing, financing structure (ownership vs. lease/PPA), and the current state and utility incentives that apply to a specific address.  EnergySage is a useful starting point to compare quotes from multiple installers and read independent reviews. The Massachusetts Clean Energy Center and Rewiring America also offer helpful research tools.

This page is intended as general, informational guidance and is not financial or tax advice. Incentive programs, rates, and eligibility rules can change; confirm current details with the Massachusetts Department of Energy Resources or a tax professional before making decisions based on this information.

Three Ways to Pay for a System

Before getting into the specific incentives below, it’s worth understanding the three basic ways

homeowners typically finance a solar installation, since the incentives that apply depend heavily

on which one you choose.

• Cash purchase. You pay the full cost of the system upfront and own it outright from day

one. This generally produces the strongest long-term return, since there’s no financing

cost, and you’re immediately eligible for every ownership-based incentive: the state tax

credit, SMART payments, and the sales and property tax exemptions described below.

The tradeoff is the size of the upfront cost.

• Solar loan. You finance the purchase through a bank, credit union, or lender, but you

still own the system, so you still qualify for the same ownership-based incentives as a

cash purchase. Monthly loan payments are often lower than a homeowner’s prior electric

bill, so many homeowners start saving from month one, though the total cost over the life of the loan is higher than paying cash due to interest.

• Lease or power purchase agreement (PPA), collectively called third-party

ownership (TPO). A third-party company finances the system installed on your roof, and

you pay either a fixed monthly lease payment or a per-kWh rate for the electricity it

produces, typically at a lower rate than your utility would otherwise charge. There’s no

upfront cost to you. Because the company owns the system, it claims any ownership-

based incentives, though competitive providers typically reflect that value in your

monthly rate. This option is discussed in more detail further down.

Deciding on how to pay is very individual specific due to tradeoffs. Solar Loan and TPO are both valuable $0 down options whereas cash requires an upfront payment. With a loan you own the

system from day one whereas with a PPA you are contracting to buy electricity from the system,

often at a lower rate. Monthly payments with a PPA may be fixed or may escalate over time.

Recent policy changes eliminated a 30% Federal Investment Tax Credit (ITC) for projects

financed through cash and loans. However, TPO can still monetize Federal Investment Tax

Credits. Additionally variability is introduced with different interest rate, term lengths, equipment

and warranties. All of this complexity introduces the need for clear, transparent information. It is

therefore important to have an objective system for comparing installers and the different

financial products they offer in real time without pressure or bias. The Terawatt Platform walks

users from high level basic savings analysis to a fully designed solar system and multiple vetted

installer quotes in 1-2 minutes. EnergySage enables installers to return bids in a day or two and

Google Project Sunroof gives a basic savings estimate.

Understanding Warranties

A solar system is meant to operate for 25 to 30 years, so the warranties attached to it matter as

much as the price. There are three distinct types worth understanding, since each is issued by a

different party and covers a different kind of problem:

• Product warranty. Issued by the panel and inverter manufacturers, this covers

manufacturing defects in the physical equipment. Industry-standard coverage on quality

residential panels now commonly runs 25 years, up from the 10-to-12-year terms that

were typical a decade ago. Panels and inverters may have different warranty periods so it is important to know both.

• Performance warranty. Also issued by the manufacturer, this guarantees that panels

will keep producing at least a specified percentage of their original rated output as they

age, commonly around 85-90% of original output after 25 years, reflecting a slow,

expected annual decline in production.

• Workmanship warranty. Issued by the installer rather than the manufacturer, this

covers the quality of the installation itself such as roof penetrations, mounting hardware,

and wiring. Terms vary far more widely here than for the manufacturer warranties above,

commonly ranging from about 5 to 10 years, with some installers offering longer

warranties.

When comparing quotes, it’s worth asking for all three warranty terms in writing, not just the

headline price, since a cheaper system with weak workmanship coverage can end up costing

more over time.

Battery Storage: Resiliency Plus a Better Return

Pairing solar with a home battery is worth a serious look — and not just for backup power during an outage. That added resiliency is valuable on its own, especially if severe storms and power disruptions become a more regular concern in New England.

Storage also has its own incentive layer. Utility-run programs like ConnectedSolutions and

related battery rebate programs pay homeowners for allowing their battery to discharge stored

energy back to the grid during periods of peak demand, typically worth several hundred dollars

or more per year, depending on battery size and program enrollment. Stacked together, these

programs can meaningfully shorten the payback period on the storage portion of a system, on

top of the peace of mind a battery provides.

FAQs

Can you tell me more about how rooftop solar works? A solar energy system converts sunlight into electricity for your home. It typically consists of solar panels, which capture sunlight and generate electricity, and an inverter, which converts that electricity into the form used by your home’s appliances. The system stays connected to the grid, enabling your home to use solar electricity produced in real time and bank any excess energy as credits. In Massachusetts, the grid banks all credits for free through a process called net metering, letting residents draw back their stored credits when needed — for example, at night or during the winter months. Over a full year, a well-sized system can offset most or all of a household’s electricity use, and because you stay connected to the grid, you never have to worry about running out of power.

What are my options for paying for a system? Cash purchase — you own it outright, with the strongest long-term return and full access to ownership incentives. Solar loan — still ownership, often a lower monthly payment than your prior electric bill, but more total cost over time due to interest. Lease/PPA (third-party ownership, or TPO) — a company owns the system and you pay a fixed lease or a per-kWh rate, with no upfront cost but no ownership incentives directly to you.

Does going solar still make financial sense without the federal tax credit? Yes, for many households. Installed costs have continued to fall, the Massachusetts state tax credit (15% of net cost, up to $1,000) is still available to system owners, SMART 3.0 pays owners a locked-in rate per kWh for 20 years, sales and property tax exemptions remain in place, and rising electricity rates increase the value of the power your own system produces.

What warranties should I ask for? Request all three in writing: the manufacturer’s product warranty (defects, commonly 25 years), the manufacturer’s performance warranty (guaranteed output, commonly 85–90% of original after 25 years), and the installer’s workmanship warranty (installation quality, commonly 5–10 years, though some installers offer longer terms).

Should I add battery storage? It’s worth a serious look. Beyond backup power during outages, programs like ConnectedSolutions pay you for allowing your battery to discharge to the grid during peak demand, which can shorten the payback period on the storage portion of your system.

Where can I compare options and get quotes? The  Terawatt Platform walks you from a basic savings estimate to a fully designed system and vetted installer quotes in 1–2 minutes. EnergySage collects installer bids within a day or two, and Google Project Sunroof offers an immediate estimate after entering your address.   The Massachusetts Clean Energy Center and Rewiring America also offer helpful research tools.

What if my roof isn’t a good fit for solar? If it’s heavily shaded, near the end of its life, or poorly oriented, it’s worth re-roofing before installation. If your roof still won’t work, community solar lets you subscribe to a shared array and earn bill credits without installing anything on your own home — a good option for renters too. Learn more about Community Solar here.

What are the steps of going solar after I choose an installer? Once you have approved a design and signed off on the financials, the solar installer will handle the installation, checking roof structural support, doing an engineering report, pulling permits, obtaining equipment and scheduling the work. It may be a month or two until installation. Actual installation usually takes 2 days – electrical work and roof racking on day 1 and panel installation on day 2. After building and electrical inspections, your electric company will install a new meter and give you approval to power up your system called PTO.

Do I have to maintain my solar system? Generally, the panels will sit up on the roof out of sight and out of mind, powering your home, even on cloudy days. There are no maintenance contracts to buy, and New England weather will keep the panels pretty clean.

What happens when it snows? Snow will pile up on solar panels, but the sun’s energy soon melts the bottom layer next to the panels and the snow will come sliding down quickly. Snow guards are available to protect people and plants under the panels.

What about critters? If you frequently see squirrels on your roof, you can add critter guards to prevent them from damaging your system wiring.

How big should my solar system be? Since selling excess electricity isn’t that straightforward (yet!), it makes sense to have a system that is properly “sized” just to cover your electric bill. However, you may decide to install a bigger solar system with future added electricity use in mind, like an electric car, or air-source heat pumps for heating and cooling.

How do I get paid for the electricity my system sends to the electric grid? On the days that your system makes more electricity than you consume, your net meter will run backward. This is called net-metering. When you underproduce and need more power, your meter runs forwards. Eversource will only charge you for the extra amount of kWh (kilowatt-hours) you used, and only give you credits for the extra electricity in the form of KWH.  When your system has overproduced, Eversource will keep credits for  your extra KWH in reserve. Those credits get applied to your bill during less productive times, like, winter months, or when your panels are not producing as much.   Learn more here.  If, at the end of a full year, you still have a credit, you can give the extra credits  to a friend, relative, or donate them to your favorite charity by way called “Schedule Z”.

What happens when the grid is down? If you’re looking to keep powering your home when the grid is down, consider a backup battery system.  Otherwise, if there is a power outage, your home will not have power and electricity generation will be disabled.