Green Newton

How does solar electricity work?

Solar electric systems, also known as solar photovoltaic or solar PV, converts sunlight into electrical energy through an array of solar panels that connect to a building’s electrical system or directly to the electrical grid. The Massachusetts Clean Energy Center (MassCEC) has some good background information on this here.

Why is this a good time to go solar?

The cost of electricity is rising and the efficiency of solar panels continues to improve. The time is now for residential solar installations in Massachusetts because we have great financial incentives at both the federal and state levels.

How do I know if my home is good for solar?

You can view your roof on Google Project Sunroof and get a quick evaluation of the available square area of your roof and the approximate number of hours of useable sunlight per year (just enter your address and click on Check My Roof). South-facing roofs with little shade are best, but east- and west-facing roofs can work as long as there is little shade. Ideal roofs have large expanses of open areas but panels can be placed on smaller areas as well. Remember that this is just a rough assessment, and you should request a free site visit from a solar installer to get a more thorough determination of your home’s solar potential and payback periods for your specific roof. Solar panels can be installed on many types of roofs, such as asphalt shingle, raised seam metal, and even slate.

What if I live in a rental property or if I own a property that I rent out to others?

Renters cannot authorize installation of a solar system; only the property owner can. Owners of rental property can authorize installation of a solar system. You should explain your situation to the solar supplier so they can provide the best possible solution. You can also help promote solar in our area by opting up to 100% renewable energy with Newton Power Choice (click here) or by signing up for a community solar project (click here), where you can own a share of a regional solar farm and get a reduction in your electricity bill. No need to choose one or the other – you can do both!

What if I live in a condo that I own?

You can download the DOER Solar Guide to Condos which provides in-depth advice about how condo owners can go solar, including how to deal with condo-associations.

If my roof is old should I replace it before installing solar panels?

If your roof is in need of repair or replacement, you should get that done before installation of solar panels. If roof work is needed later, you will have to pay for some or all of the solar panels to be removed, stored, and reinstalled after the roof work is completed. Generally, you will want to install panels on roofs that are less than 10 years old. That way the life of your roof and the solar panels will be aligned. Your installer can help determine if it makes sense to replace it before installing solar panels.

What regular maintenance is required for a solar system?

Your solar system should be mostly maintenance free over its 25+ year life. Rain and snow will generally keep the panels clean and free of debris. Removing snow is not recommended since you risk damaging the panels. Since they are made of smooth tempered glass, snow slides off the panels as sunlight begins to warm the panels.  Even if your internet or reporting system goes down, the panels will keep producing and your electric meter will run backwards. It is rare for the panels to stop functioning.

I have some shade. Can I still benefit from solar PV?

Usually you can. It depends on how much shade you have and much shade falls on the roof areas that will have solar panels. Even with shading, our suppliers are now offering very efficient panels that can make your project viable even if it was not financially attractive a few years ago. In some cases, you may consider thinning branches or removing some trees to allow the solar panels to operate more efficiently. Your solar consultant can discuss this with you. If you are doing tree work as part of a customer owned system, you will be able to take the tax credits on the cost of the tree work.

Is solar really viable in New England?

Absolutely! Our available sun power in New England is about 80% of the sunniest parts of the southwestern US and is much higher than anywhere in Germany, one of the leading solar countries in the world. We also have relatively high electricity rates, which makes solar PV systems more economically attractive. Economic viability for solar is greatly enhanced by financial incentives for solar system owners, and Massachusetts is one of the most “solar-friendly” states because of our progressive state solar policies. The state incentives are a combination of state tax credits and 10-year earned credits from SMART. For customer owned systems, the expected breakeven time is generally between 5 – 7 years on the purchase cost, but will vary depending on roof orientation, shading, and other factors. Homes with more shading have longer payback periods, but solar can still be a great investment in these situations. Due to improvements in solar panel efficiency, some homes that were previously not good candidates for solar installations may now be economically viable. Solar panels can be effective on most roofs, regardless of orientation.

Will cold weather affect the operation of a solar system?

Colder operating temperatures are actually better for solar PV. Although it may seem that desert conditions would be ideal for solar PV, the intense heat decreases the efficiency of the solar panels. Cooler temperatures allow the system to operate at higher efficiency.

Will I still generate electricity on a cloudy day?

The electricity production will be reduced on cloudy days, but the system will still generate some electricity because there will still be some sunlight falling on the panels. On a light overcast day, panels might produce about half as much as under full sun.

Will I still generate electricity when it snows?

When it snows, the snow may initially cover most of the surface of the solar panels and greatly reduce the production of your system. However, if the snow is light, some sunlight will still be able to penetrate through to the modules, warming them and melting the layer of snow that is on them. Snow typically clears from your solar panels much sooner than other parts of the roof, allowing production to return to normal. Make sure you speak with your installer about using snow guards or panel placement to ensure that snow falls in a safe spot.

What would make my roof not suitable to for solar PV?

Suitability depends on your available clear roof area (free of chimneys, vent pipes, etc.), orientation, shading, and condition of your roof. If you don’t have enough area and sun to illuminate your panels for most of the day, you may not be able to produce enough electricity to cover a large percent of your electricity requirements. At that point, the cost of installing the solar system may make less economic sense.

How big should my solar system be?

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 demand in mind, such as an electric car, electric heat pumps for heating and cooling, or electric heat pump water heaters. You should also discuss whether you need to upgrade your electrical system to 200 amps or higher with your installer or an electrician.

Will my property value go up with a customer owned system?

Imagine two identical homes next to one another, one with an installed solar system and one without it. It is reasonable to expect that the house with the customer owned solar system would be worth more because the homeowner would pay much lower electric bills. A Lawrence Berkeley National Lab study (using data from real estate sales in California and in 7 other states including Massachusetts) concluded in 2015 that the premium paid for homes with installed solar PV systems was about equal to the initial cost of the PV system. See: https://newscenter.lbl.gov/2015/01/13/berkeley-lab-illuminates-price-premiums-u-s-solar-home-sales/.
For a typical home with a 7kW system, this would represent an increase in value of around $21,000 to $28,000 (around $3 to $4 per installed watt). There are now excellent continuing education courses for real estate agents so they can better understand how to sell a home with a solar system.

What is the process of going solar?

Generally, a solar installer will request a copy of your electric bill and prepare a proposed layout and financial estimate based on your usage and your available roof space. Some parts of your roof may get more sun than others; you can change the layout to meet your needs. Once you have approved the design and signed a contract, the solar installer will handle the installation, checking roof structural support, pulling permits, obtaining equipment and scheduling the work. It may be a month or two until installation. Actual installation is usually completed in one or two days. After required electrical inspections, Eversource will install a net meter and give you approval to power up your system.

What is net metering and how does it help the solar customer?

Currently, residential solar systems in Massachusetts are allowed to use net metering if the system rating is below 10 KW DC. Net metering means that you get credited for every kWh of electricity produced by your solar system, regardless of whether you use that electricity now or at some point in the future. For example, in the summer months, you will typically produce more electricity in a month than you consume, but the excess electricity that you did not use gets put back on the electrical grid and you get full credit for that electricity when you need to use it later, such as during the winter months. Think of it like rollover minutes on a phone plan; they can be carried forward to the next month. You can use the electricity either now or later, and you will get credit for it either way.
Net metering is done by changing the utility electric meter on your home to a special type of meter (a net meter) that can run forwards and backwards. When you are using more electricity than you are producing, the meter runs forwards, and when you are producing more electricity than you are using, the meter runs backwards. Your utility bill is based on the net meter reading each month, and for months where you produce more electricity than you use, the net meter reading for the month will be negative, and you will get a credit on your bill for the excess electricity that you put back onto the grid. This credit can be used in later months when you use more electricity than you produce. For both PPA and Customer Owned systems, you will get a net meter installed, and you will be able to take full advantage of all the electricity that you produce (if your system rating is less than 10 KW), regardless of how much of it is used in a given month.

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 meter will run backwards through the net metering system. If you produce more than you use during a given month, you will generate a credit on your electricity bill for the retail value of the electricity produced. Those ‘credits’ will offset the cost of electricity during those months when you use more electricity than you produce, such as in winter. If at the end of a full year you still have a credit, you can assign it to any other electricity user in your load-zone. Get more information on net metering here.

What can I do to reduce my electricity consumption so I can have a smaller solar system?

It is always good to reduce unnecessary electricity use as much as possible. This will allow you to address a larger percentage of your electricity consumption with solar energy, or even allow you to use a smaller solar system. Use energy efficient LED light bulbs, replace older appliance with the more energy efficient ones, use power strips with on/off switches to turn electronics truly off when not in use, and be good about turning off light and electronics off when you are not actively using them.
A great place to start is to schedule a free MassSave home energy assessment. You will receive free air sealing, programmable thermostats, low flow shower heads, smart power strips, as well as energy savings tips and advice. There are also opportunities to save on insulation (they pay for 75% of costs) and weatherization services. We recommend scheduling your free assessment through our recommended assessment partner HomeWorks Energy or the City of Newton’s partner Endless Energy, but you can get this done for free by any participating MassSave partner. This program is free to you, because it is paid for by fees that you already pay in every electricity and gas bill.

What is the difference between a PPA system and a customer owned system?

A customer owned system is a solar installation that the homeowner purchases and wholly owns. The homeowner receives all available federal and state tax credits and incentive payments to reduce the overall cost of ownership. The homeowner also benefits by using all the electricity produced by the solar system to significantly reduce or possibly eliminate their electric utility bill. The customer owned system provider is responsible for maintenance and repairs for the term of their warranty (typically 5 to 10 years). Studies clearly show that customer owned systems provide much higher financial benefits than a PPA system. There are many options for solar loans in Massachusetts including the Mass Solar Loan program so that is it not necessary for you to have to have extra funds saved to invest in a system.
A Power Purchase Agreement (PPA) allows a solar customer to enter into an agreement whereby a solar system is installed on the roof at zero cost in exchange for reduced electricity costs (usually around 10-20%) for the period of the agreement (usually 20 years). Some people call this “leasing” their roof in exchange for a discount on their electricity. The system is owned by the PPA solar company, and all electricity produced by the system is sold to the solar customer at a contract price.
The remaining electricity that is not produced by the PPA system is billed to the customer by the electric utility at normal rates. The PPA solar company is the system owner and receives all tax credits and state incentive payments, which allows them to offer the system at no upfront cost. The PPA solar company is also responsible for maintenance and repairs, as their revenue model depends on the system providing good service. Things can be more complicated if you have a PPA and want to sell your home. In most cases, a new owner may want to assume the agreement you had, however, sometimes this will not be the case.

What are all the financial incentives available for customer owned systems?

A provider can explain to you all the incentives available during the estimate and calculate your net cost for you.
Federal Tax Incentive
The system cost can be taken as a credit against your federal income taxes for the year you install your system. If your tax credit exceeds your tax liability in the year that you install the system, you can carry forward unused credits for a limited period of time. Any additional work such as tree removal, roof replacement, or electrical system upgrades that are done as part of the solar installation will usually qualify for the tax credit (please consult a tax professional about your personal situation). The federal tax credit for systems installed starting in 2023 is 30%.
State Incentives
• 15% of the system cost can be taken as a Massachusetts state tax credit, up to a maximum of $1,000.
• Purchases of residential solar systems are exempt from Massachusetts state sales tax.
• Under Massachusetts law, the installation of a solar PV system is exempt from property tax increases for the first 20 years of use. Your property taxes can go up for other reasons, but they cannot be raised due to the addition of a solar PV system for the first 20 years of ownership.
The Solar Renewable Massachusetts Renewable Target (SMART) Incentive
The State of Massachusetts pays residential electric customers a fixed rate per kilowatt hour (kWh) of solar energy produced for the first 10 years of ownership. For systems under 25 kilowatts (kW), the rate ranges from 25 to 30 cents per kWh, depending upon your location and utility. In addition, the state provides higher incentive rates for low-income customers or those who install battery storage to pair with their solar panel system, making solar power more accessible to more customers in the state. SMART payments will decrease over time and will decrease as the cost of electricity rises.

What would happen to my SMART incentive payments if I sold my house with in the first 10 years of operation?

If you sell your property before the first 10 years has passed, the balance of your Solar Renewable Massachusetts Renewable Target (SMART) incentive payments would be negotiable between you and the buyer.

Is there a website where all the solar suppliers are rated, where I can read comments about them?

Yes, you can go to Energy Sage to read about users’ ratings of many different solar suppliers, and they have a star rating system. Keep in mind that there are ratings and comments here for solar companies all across the US, so enter your zip code and distance in miles from installer to see reviews for installers in our area.

Could I get a loan for the substantial tax credits to cover the time between when I purchase the system and when I actually receive my tax refunds?

Yes. Many solar companies offer a 0% tax loan program to cover the tax credits. If you choose to take advantage of this loan, you will not have to pay anything until after your federal and state tax refunds are received, and you will pay no interest as long as the loan is paid off before the 0% interest rate period expires.

What happens at the end of a 20-year PPA contract?

At the end of the agreement term, you can either extend your agreement, have the solar provider remove the system at their cost, or buy the system at fair market value.

What happens if I sell my house?

When selling a house with a customer owned system, the installed solar system is part of the property, adding value to the home due to its ability to provide free electricity to the new owner. This is not true for a PPA system.

Why do some solar suppliers use microinverters, and some use power optimizers with a central Inverter?

MicroInverters or the combination of power optimizers and a central Inverter accomplish the same thing—they both convert the DC electric current produced by the solar panels to an AC current that can be used in your house. They help maximize the capture of electricity produced from your solar panels. They also enable all of your solar panels to be monitored remotely so problems can be spotted easily. Both solutions are popular and both operate at high efficiency. Most experts are split on which type of system is better. Many solar companies use one type, and others may offer you a choice. There are slight differences in equipment, warranties, and costs for the two system types. You can ask your solar supplier why they have chosen the equipment that they use.

What is a power production guarantee?

A power production guarantee is a statement written into the contract that specifies the minimum solar production (in kWh) expected per year for your solar system. The number will decrease slightly each year because solar panels become slightly less efficient as they age. If your solar production falls short of the amount specified in the production guarantee, the supplier will reimburse you for the production shortfall, at the rate per kWh that is written into the contract. Power production guarantees are not generally used with PPA systems because the PPA system provider is already motivated by the nature of the agreement to insure that the panels produce as much electricity as possible.

Will my solar panels produce electricity during a power outage?

No. The solar PV system is wired into your electrical panel, and for safety reasons, is designed to automatically disconnect in the event of a power outage. When grid power is restored, the system will automatically reconnect and synchronize to the grid and your solar system will come back on. Systems with battery backup will operate during a power failure.

What if I want to go off-grid and install a battery backup system?

Since we are in a developed urban area, we have a very reliable electric grid, and moving off-grid is not generally needed in Newton and surrounding communities. However, these systems are available and becoming more popular. They are more popular in states where there is no net metering.

Do I need to contact my homeowner’s insurance company if I add solar?

Because you do not own the solar PV system with a PPA agreement, the insurance is maintained by the solar company and you do not need to contact your homeowner’s insurance company. If you choose a customer owned system, it becomes part of the structure of the home, and  you should inform your homeowner’s insurance company. In some cases, they may add a small fee to cover the solar system, but most likely they will not. The homeowner’s insurance would be liable if for instance, a tree fell on your roof and smashed some of the panels.

How long would it take to get a solar PV system installed and inspected?

From the time you sign a contract, it can take a couple of months until the system is installed and inspected. Your solar installer can give you more details on how much time it should take.