That's a lot of money!
Heat pump water heater
You are in a town with municipal utilities. Unfortunately, rebates are only available to homes that have participating utilities, but you are still eligible for tax credits!
You qualify for the Mass Save Income eligible program. This program has better incentives and more holistic coverage. You can find more information about the program and find a local provider here.
Mass Save only offers rebates for homes that are occupied year-round, but there are some tax credits you are eligible for!