Mathew Tuttelman decided he was never going to pay a utility bill again — no gas, oil, or outside electricity to heat, cool, or power his 3,500-square-foot home. He was going to build a net-zero home, a structure that produces as much energy as it consumes.
Tuttelman, a senior account executive at CPower Energy where he provides energy expertise to companies, was motivated to cut his bills and his carbon footprint to combat climate change.
The 1955 Cape-style home in Needham, which his family bought in 2000, was the “perfect candidate” for the transition, he says. Between tax incentives from the state and Washington, D.C., here’s how he’s almost reached his goal.
His first move was installing solar panels in 2019.
Solar panels (33 total)
Upfront cost: $39,000
Savings: 30 percent, or $11,700, from federal incentives, plus an additional $1,000 state tax credit.
Final cost: $26,300
Payback: $4,500 annually
Estimated system payoff: 5.5 years
Source: Mathew Tuttelman, Energy Star, Mass. Department of Revenue
Next move: a home battery in his basement that stores energy to run his home in the event of a power outage. Last year, Tuttelman’s family lived through a 36-hour power outage, comfortably, thanks to the system.
Battery
Upfront cost: $23,000
Loan: Borrowed the money at zero percent interest on a seven-year loan
Estimated system payoff: 3.5 years
Source: Mathew Tuttelman
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Then he insulated his home, creating a seal to keep heat from escaping.
Insulation
Upfront cost: $3,300
Savings: Mass Save picked up 75 percent.
Final cost: $740.
Source: Mathew Tuttelman, Mass Save
Last move, ditching the gas furnace and replacing it with two geothermal heat pumps, which use warmer temperatures underground, between 45 and 75 degrees Fahrenheit depending on the location, to transfer heat to the home in winter. Then in summer, when the ground below is cooler than the air, the system works in reverse.
Heat pumps (2)
Upfront cost: $50,000
Savings: $15,000 from Mass Save, then a 30 percent tax credit from Washington DC, knocking off an additional $10,500
Final cost: $24,500
Estimated system payoff: Between 7-8 years
Source: US Inflation Reduction Act, Mass Save
Last year, a team from Dandelion Energy, a company that installs geothermal systems in the Northeast, drilled two 5-inch diameter boreholes, 350 feet deep, in Tuttelman’s yard. Then, the company connected the boreholes with lines that come into his house through the basement. Water and antifreeze solution coarse through pipes where the heat exchange occurs.
“It seemed like it was a no-brainer,” Tuttelman said. “A better technology that was going to use no fossil fuel, was going to be more efficient, and someone else was going to pick up more than half of the cost.”
The total price tag for the entire home project was roughly $75,000, after rebates. But Tuttelman says it will pay for itself in about six years through energy cost savings.
Other benefits include the stress savings of not having to guess when a furnace, which typically lasts about 15 years, is on its last legs. The underground infrastructure for geothermal heat pumps can operate for 25 to 50 years, according to the US Department of Energy.
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His steps taken collectively, Tuttelman is close to his goal of living in a fully net-zero home. He still wants to install new windows to lower his energy needs and get rid of his hot water system that runs on gas. To do that, he needs to install a heat pump water heater.
John Sterman, a professor at MIT’s Sloan School of Management with a focus in sustainability, achieved the holy grail of net zero eight years ago. His 1920s Lexington home was due for an update, but instead of just “upgrading and renovating,” Sterman decided the “incremental cost of going deeper and doing a retrofit” was the right move.
A deep energy retrofit enhances a home’s sustainability and environmental footprint by using a “whole-systems approach.”
Sterman said he asked himself what actions would have the biggest payoff and went from there. For example, his home’s original windows from the 1920s were in rough shape, so he decided to tighten the building’s envelope, resulting in wider windowsills, where, added bonus, he can now display a robust plant collection.
Window replacement
Upfront cost: Highly variable by quality, size, and design.
Estimated savings: 7 to 15 percent on annual energy bills.
Federal tax credits: Up to $600 (or 30 percent of product cost) for upgrading windows in one taxable year.
State rebate: Mass Save offers $75 rebate per Energy Star window
Source: Energy Star, Mass Save
His remodeled home, which includes an air-source heat pump and solar panels, now produces roughly 40 percent more energy than it needs, all with zero fossil fuels. “My house is now a power plant,” he likes to say.
He estimates that without the retrofits, his annual gas and electricity bill would be about $3,200. Instead, he gets paid about $3,375 for his excess solar electricity production, in addition to charging two cars for free.
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Heat pump water heater
Average installation cost: $3,200 according to Mass Save
Estimated savings: Medium-sized households save $410 per year according to the Department of Energy.
Federal tax credits: 30 percent of project costs, up to $2,000
State rebate: Mass Save offers Up to $750 per unit
Source: Energy Star, Mass Save
Sterman acknowledges that he had the luxury to afford these investments, but says the economics have shifted dramatically since his installation — subsidies, tax credits, leases, and loans have made solar panels and heat pumps much more affordable. And while taking the plunge can be daunting, between the upfront cost and time investment, he says people should “consider the costs and benefits, not just the costs.”
At his home: no more cold spots in winter, ice dams, or risks of frozen pipes. With the radiators removed, he has more space. And with no fossil fuels used for cooking, his family has no exposure to pollutants that can cause respiratory problems.
“It’s a safer, more comfortable, quieter, and bigger place than it was before,” says Sterman. “All these benefits came as part of the deep energy retrofit.”
Alexa Coultoff can be reached at alexa.coultoff@globe.com. Follow her @alexacoultoff.