Solar Guide
This page contains helpful information on a variety of topics related to solar.
Scroll down or click on the appropriate link below for info on the following topics:
Solar Basics
Curious whether solar is right for you? Not sure where to begin? Here are some helpful pieces of information to get you started.
What ownership options are available?
Solar companies typically offer a few different ownership options: direct ownership, lease, or Purchase Power Agreement (PPA). A PPA consists of the solar company owning the array and selling you the electricity it produces. RMLD customers must own or finance the system; third party electricity sales to municipal utility customers (such as a PPA) are not allowed per MA state law.
How do I know what size system I need?
The system should be sized to roughly match the electricity consumption of the home or business where it is being installed. RMLD recommends that system capacity be no greater than 80-90% of the customer's kilowatt hour energy usage. The average residential system size in Massachusetts is 6.3 kilowatts (kW). This size system has the capacity to produce about 9,000 kilowatt hours (kWh) per year. Commercial system sizes vary.
How do I know if my roof is right for rooftop solar?
The roof's structural and surface condition should be evaluated prior to installation to ensure repairs and/or replacement will not be needed in the near future. Roof orientation, tilt, and shading are also important considerations that impact a system's operating efficiency as well as a customer's eligibility for rebates.
- Roof orientation: south facing is best
- Roof tilt: a 30-45 degree angle is best (this is typical of most New England homes)
- Shading: ideally, a system should have no shade for a minimum of six hours per day (to qualify for the MLP Solar Rebate Program, shading must be less than 20%)
About how much will a system cost?
System cost will differ by size and installer. The table below illustrates the potential net cost of an average-sized residential solar system (6.5 kilowatts) after incentives, as well as the expected timeframe to achieve return on investment.
System Size | Average cost per watt installed (MA) | RMLD Solar Rebate Program | Massachusetts Tax Credit (Maximum of Either) | 2022 Federal Investment Tax Credit | Net Cost After Incentives | 2023 Federal Investment Tax Credit | Net Cost After Incentives | |
|---|---|---|---|---|---|---|---|---|
6.5 kilowatts (kW) | $3.11 | ($1,200) | -15.0% | ($1,000) | -26.0% | 2022 | -22.0% | 2023 |
| $20,215 | ($7,800) | ($3,032) | ($1,000) | ($5,256) | $4,127 | ($4,447) | $4,935 |
Estimated Years to Achieve Positive Return on Investment | 6.6 |
| 7.0 | |||||
Are there any financing options are available?
Some customers may be eligible for a low-interest, fixed-rate loan through the Mass Solar Loan Program which is run by the MassCEC and the Massachusetts Department of Energy Resources (DOER).
What happens to the excess electricity that my system produces?
On clear days during the middle of the day when the sun is at its peak, your system is likely to produce more electricity than your home will use. In this scenario, you will be credited the monthly fuel charge per kilowatt-hour for excess electricity fed into RMLD's distribution system.
More Information
RMLD held a Solar Workshop on June 20, 2019. CLICK HERE to review the materials and watch the video.
First Step - Selecting an Installer
If you've reviewed the basics and decided solar may be right for you, you're ready to take the first step: getting quotes and selecting an installer.
The Massachusetts Clean Energy Center (MassCEC) maintains a database of solar installers that have completed projects in Massachusetts. The tool can be filtered by county and provides the name of the installer, their median cost per watt, and the number of projects they've completed. Click here for MassCEC's Solar Cost Comparison Tool. RMLD also maintains a list of contractors who have done work in our territory. Here is a sample list of contractors. It is recommended that you solicit at least three competitive quotes. The installer will determine the recommended size of the system based on your electricity usage.
Once you've received quotes, the following steps are recommended:
- Check installer's references.
- Verify that installer is properly licensed by checking the MA Home Improvement Contractor Registry or the MA ePlace Portal.
- Make sure installer is bonded and insured.
Large municipal or commercial customers may prefer to issue a Request for Proposal (RFP). The US Department of Energy has created a Solar PV RFP Template that can be tailored to the needs of a particular business.
Available Rebates
Residential and Small Commercial Renewable Energy Generation Rebate Program (<20 kW)
Customers who install a grid-connected renewable energy system at their home or business that is less than 20 kilowatts (kW) in size may be eligible for a rebate of $1,200 per kilowatt (kW) (through February 29, 2024), not to exceed 50% of total installed (labor and materials) costs excluding tax up to $24,000. Beginning March 1, 2024, the rebate will change to $600 per kilowatt.
Click here for complete program requirements.
Commercial Renewable Energy Rebate Program (>20 kW)
Commercial, municipal, and industrial customers who install qualified grid-connected renewable energy systems on their property that is 20 kilowatts (kW) or greater in size may be eligible for a rebate of $1,200 per kilowatt (kW) through February 29, 2024, not to exceed 50% of total installed (labor and materials) costs excluding tax up to $24,000. Beginning March 1, 2024, the rebate will change to $600 per kilowatt.
Click here for complete program requirements.
Sample Bill
Click here to see a sample residential solar bill
Click here to see a sample residential solar bill with Time of Use.