How does solar power work? Solar electric systems, also known as solar photovoltaics or solar PV, convert 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.

How do I know my home is good for solar?  Go to Project Sunroof to get a quick evaluation of your roof. Enter your address and click on “Check My Roof.”  Roofs that face south with little shade are best, but roofs that face east and west can work if 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. You need to request a quote from a solar installer for an accurate picture of your property’s solar potential – which can include your roof and/or surrounding land.  An installer should be able to give you a good sense of your solar potential without having to visit your home, though a site visit is a good idea to confirm measurements before you decide to move forward.

What kind of maintenance is required on solar systems? A 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 yourself is not recommended since you risk damaging the panels. Your installer should be able to go over with you any maintenance needs and provide support if something goes wrong.

What is the process for 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 solar area. For roof-mounted systems, be sure to have the age and structural capacity of your roof confirmed before moving forward. For ground-mounted systems, make sure to confirm that the size and location of the system is allowed per Boxborough’s bylaws/ordinances. For details on rules governing installation of solar on residential or commercial property refer to Town of Boxborough Solar Energy Systems Zoning By-law

Make sure you and your installer understand LELD’s interconnection and net metering requirements. Once you approve the design and sign a contract, the solar installer will handle the installation, pull permits, and schedule the work. It may take a while before construction can start, depending upon LELD’s approval process and other factors. The actual installation work is usually completed in a matter of days. Once your solar array is installed and inspected, LELD will install a net meter to track the output of your system and give you approval to flip the switch!

What if my roof is old, should I replace it before installing solar panels? Generally, if your roof is at least 10 years old, it’s a good idea to consider replacing your roof prior to installing solar panels. A good solar installer should be able to help evaluate your roof’s condition. While the presence of the solar panels on your roof may extend your roof’s life by reducing UV exposure and temperature changes, you should try to avoid the cost and headache of having to remove and reinstall your solar system just to re-roof your home.

What are other benefits of solar? Solar panels are usually warrantied for 25 years, and inverters have a 10 year warranty, with little to no maintenance required. With the potential for free electricity to future home buyers, especially as electricity rates continue to climb, solar panels can increase the value of your home. Solar panels can also extend your roof life or be incorporated into other structures to provide benefits like shaded parking structures, protection for shade crops, and more.

What is net metering and how does it help the solar customer? Net metering credits you for the excess kWh of electricity produced by your solar system. The electricity you produce from your panels is first consumed in your home and then if there is excess electricity you don’t need, it goes on the grid. For example, in the summer, you will typically produce more electricity in a month than you consume, so the excess electricity that you did not use gets put on the electrical grid, which is then net metered as a credit on your LELD bill.

Net metering is done by changing the utility electric meter on your home to a bi-directional meter, or a “net meter,” that runs forwards and backwards. When you use more electricity than you produce, the meter runs forwards (taking electricity from LELD). When you produce more electricity than you use, the meter runs backwards (providing electricity to LELD). Your utility bill will display both amounts. These readings do not offset each other, they are billed through the residential rate 10 (electricity you take) and the net metering rate 70 (electricity you provide).

How big should my solar system be? It makes sense to have a system that is properly “sized” to cover your electric bill, since excess solar kWhs are credited at the net metering rate which is typically lower than. the residential rate. However, if you should consider any plans to increase your electricity consumption – through installing heat pumps or hybrid/electric vehicle charging, for instance – you need to make sure that your system will cover future needs, too. The bigger the system, the better your return on investment will be. 

For LELD customers, residential solar systems are allowed up to the lesser of your previous 12-month consumption or a nameplate capacity of 8 kilowatts (kW).

If you wish to install a larger system, you can do so up to a nameplate capacity of up to 15 kW, but to do so you must opt out of net metering, meaning you forfeit the ability to be credited for any excess kWhs that you provide to LELD.  This option makes sense for those who consume most of their energy during the day, when your solar system is at peak output, or those who want to combine solar and energy storage (batteries), which can allow you to store the solar kWhs instead of net metering them to LELD. Energy storage is expensive and very few solar systems with batteries have been installed in Boxborough to date, but it is worth a consideration as household electricity consumption is growing through adoption of heat pumps, hybrid/electric vehicles, and so on.

Other useful links:

https://www.energy.gov/eere/solar/homeowners-guide-federal-tax-credit-solar-photovoltaics