Our household has been fully decarbonized since 2023: EV car and a charger, heat pumps for space and water heating, and an induction stove. We also added insulation to the walls and attic. But getting to this stage was slow and sometimes confusing. Here is the story of this process.
We own an upstairs condo in a hundred-year-old double-decker building in Newton. That in itself makes everything more complicated than if we lived in a single-family home. We started about 12 years ago with insulation; first inside the walls, then several years later in the attic. Our neighbor’s downstairs were not interested, so we had to pay for their wall insulation as well as ours because it is impossible to blow insulation into upstairs walls without doing it also in the downstairs walls. Fortunately, Mass Save paid 75% of the cost.
Mass Save refused to insulate the attic because our old insulation consisted of vermiculite, which in some cases may be contaminated with asbestos. That meant that we first had to remove all the vermiculite. It was a very expensive job because it was treated as asbestos removal, with all the occupational safety and disposal regulations. We were lucky because our type of vermiculite qualified for a significant subsidy from Zoolite Attic Insulation Trust, which covered about half of the cost. We also received federal tax credits, which I listed on my tax return as phase one of the attic insulation project.
In 2019, we bought an electric Chevy Bolt. At that time, the incentives were very generous, including those from the manufacturer, because electric vehicles were not selling well. We went into it naively, with little knowledge about the electricity demands of a level-two charger. When the dealer told us that we needed a 200 amp electric load capacity (each of the two condo units had 60 amps) we simply called an electrician. This turned out to be a very big and expensive job of bringing new wires from the high voltage wires on the street. There was no choice but to do it quickly because we had already sold our gas-powered car (we are a one-car family). What we did not realize at the time is that the electrical contractor who brought 200 amps to the house divided it between the two condo units, each with 100 amps. It was our fault not to notice the small print in the contract, but it was also not what we hired the electrical contractor for. That error would give us many headaches in the future.
In 2022, with a well-insulated home, we bought a heat pump water heater. It all seemed straightforward until the unit started working and making a noise of about 80 decibels. The neighbor downstairs complained that she could hear it in her dining room. What to do? We put insulation in the attic ceiling, and when that was not enough the contractor installed a different fan unit. Today, with 60 decibels volume, it is still not perfect, but our neighbor learned to live with it.
In January 2023, we decided to install a heat pump heating system. It would be too expensive to consider removing the perfectly good gas-fired heating system, with its ancient cast iron steam radiators, so we planned to leave it in place. In all honesty, I like to have it as security, in case the heat pump system fails. Since our condo had central air conditioning, with ducts in the attic, the contractor was able to use the same ducts. In our enthusiasm for complete decarbonization, we also brought a 240-volt electric outlet to the kitchen in anticipation of an imminent purchase of an induction stove. This is when things got complicated because of our 100 amps electric system.
We received three similar quotes for the heating system. Two contractors said that our electricity was adequate for a heat pump heating system, but they did not ask any questions about the other uses of electricity. The third contractor took a more comprehensive view, considering the electric car and our interest in an induction stove. He told us that our system was inadequate, and that we need to upgrade it to 200 amps. We chose this contractor to install the heating system because we liked their thoughtful and comprehensive approach. For the time being, we postponed the purchase of the induction stove and charged our car only at night.
Once installed, the new heating system required various adjustments. First, the temperature variations were large, +/- 4 degrees from the set temperature; Second, the thermostat did not work properly. The contractor came back to install an additional temperature sensor on the ceiling of the living room, far away from the thermostat, and came four more times to try two other thermostats, to program them according to our lifestyles, and to instruct us how to use them. For example, we like to open windows on mild days year-round, to sleep in a cold bedroom in winter and without air-conditioning in the summer, and we want to keep the overall temperature low when we travel.
All the thermostats come without instructions; and we learned that the people who install heat pumps do not necessarily know anything about thermostats. In the end, we resigned ourselves to living without a programmable thermostat. After all these glitches, we are now satisfied with how the system works and we greatly appreciate the exceptional customer service from the contractor. Their knowledge that I am the Chairperson of Newton Citizens Commission on Energy probably helped.
The City inspector who came to check the heating system and learned about our plans to buy an electric range refused to approve the project until we upgrade our electricity to 200 amps. Back to calling electricians and getting quotes. Here, we also learned that electricians often have very different opinions on the right way to do things. There are apparently many ways to upgrade electricity in a hundred-year-old two-unit house, and every electrician we spoke to was eager to tell us what the guy before him did wrong and how he fixed it. How should we, who are ignorant about electrical systems, sort this all out?
It turned out that upgrading the electricity would be very expensive—well over $10,000—and more than double the cost of the heat pumps. Bad news. Fortunately, the electrician who was involved with installing our heat pump system and the city inspector really wanted to help us solve the problem. Together, they found a solution: a load manager. At a quarter of the price of an electrical upgrade we now have two load managers that make sure that we never exceed the 100 amps capacity of the system. One of the two controls the car charger and the other controls the clothes dryer. When the stove and the heating system are going full blast, the clothes dryer and EV charger have to take turns until the electricity demand declines. We can easily live with that.
In the summer of 2023, we installed a 240 volt electrical outlet in the kitchen, bought an induction range, and replaced almost all pots and pans with magnetic ones.
This is our story, with many complications and a happy ending. But it took several months to figure everything out. I have since spoken to people who installed heat pumps and learned that they have all kinds of bloody stories to tell about complications and confusing advice. I am sure that in a few years things will run more smoothly, but for now, innovators and early adopters like us should have a forum for sharing their experience and helping the newcomers to ask the right questions. We would have avoided a lot of problems with electricity if we spent more time with the initial electrician, making sure that they properly prepared our house for the future full electrification.
I also wonder what the world would look like if women entered these occupations. I have yet meet one woman in the business of installing heat pumps or doing electrical work.
Costs after state and federal incentives (some are approximations)
Project
| Wall insulation | 1600 (for two units) |
| Asbestos removal | 2439 |
| Attic insulation | 404 |
| Water heater | 3136 |
| Heat pump space heating system | 5577 |
| Electricity upgrade from 60 to 100amps | 7755 – 2000 (neighbor’s contribution) = 6755 |
| Load manager | 3277 |
| 240 volt outlet in the kitchen | 300 |
| Induction range | 1688 |
TOTAL $25,176
Operating cost: Savings and increases
I estimate that the wall and attic insulation reduced our heating energy use by about 20%. Shifting from gas to electric space heating reduced our energy use for heating by about 33%.
Car maintenance and fuel reduced the cost of using the car quite significantly, though I cannot put a number on it.