Official Sources
Every rebate estimate, eligibility rule, and data point on this site is sourced from an official government or program page. Sources are listed here with last-checked dates.
We manually review official program pages and link directly to primary sources. We do not generate rebate data from secondary sources or AI-summarized content. When a source changes, we update the affected pages and log the change. Rebate amounts shown on calculator pages include confidence scores and last-checked dates.
Mass Save Program Sources
Program overview, participating utilities
Category discovery and program navigation
Heat pump rebate tiers, eligibility, fuel type rules
Insulation/air sealing incentives
Rebate amount, ENERGY STAR requirements
ConnectedSolutions battery incentive details
Demand response incentives for battery and thermostats
Financing guidance and zero-interest loan details
Massachusetts Solar Sources
MA solar incentive program overview
Applications, official calculator, program rules
Federal Sources
25C and 25D credit rules, caps, eligible expenses
Federal home upgrade rebate/tax credit context
Product and Utility Data Sources
Certified product datasets and eligibility
Solar production estimates
Utility rate structures
Electricity, fuel, and state-level price assumptions
This site is not affiliated with Mass Save, the Commonwealth of Massachusetts, the IRS, ENERGY STAR, or any utility. Sources are provided for reference and transparency. Rebate data can change — always verify with the official source before assuming eligibility.