I undertook my recent constituent surveys about heat pumps because I was struggling to understand why heat pump adoption rates are so low. The survey responses tend to confirm that raising adoption rates will be difficult and expensive.
Many believe that the current generous incentives offered by Mass Save will not suffice to drive heat pump adoptions at a pace sufficient to accomplish our stated climate goals. This is a consensus conclusion of the recent Commission on Clean Heat. It is also the central judgment behind the low target set by the Secretary of Environmental Affairs for emissions reductions through the Mass Save program.
The projections of low heat pump adoption rates come partly from historical experience and partly from “potential studies.” Mass Save hires consultants who use proprietary models to estimate potential uptake of proposed incentives. Recent potential studies suggest negligible heat pump incentive uptake for homes heated with gas (the majority of homes) and low single-digit rates of annual uptake for homes heated with oil.
The consultants do not expose the inner logic of their models, so I wanted to see if constituents’ feelings and experiences were consistent with the model projections.
Quantitative Survey Results
The full quantitative results of the survey appear here. This summary table tells much of the story:
Small Building Homeowner Follow-up Table 7 (N=692): Summary of likelihood to convert results
|Combined affordability and other likelihood to convert factors
|% of sample
|1. Not interested in heat pumps
|2. Will convert only if cost-effective based on both operating and capital costs
|3. Will convert only if net upfront cost under $10,000
|4. Unsure how much they can afford
|5. Can afford net over $10K, but need minisplits and not OK or unsure about them
|6. Can afford net over $10K, and have vents or are OK with minisplits, but will not consider replacing before failure of current system
|7. Can afford net between $10K and $30K, and have vents or are OK with minisplits and will consider replacing before failure of current system
|8. Can afford net up to $50K, and have vents or are OK with minisplits and will consider replacing before failure of current system
|9. All homeowners in follow up affordability survey (N=692)
We know that whole home heat pump conversions (where fossil fuel back up is eliminated) cost an average of $21,000 per housing unit, much more than a replacement oil or gas burner. That cost varies widely and does not include weatherization and other costs which may or may not be covered by Mass Save. We also know that, under current market conditions, heat pumps increase annual heating cost for homes heated with gas and may or may not offer savings for homes heated with oil. So, even with a $10,000 incentive, heat pumps are only likely to be adopted by people who are motivated to cut carbon emissions and have considerable discretionary resources — in other words the 11% of the survey respondents in lines 7 and 8 of the table above.
Qualitative Survey Results
When one looks at the over 150 qualitative comments offered on the survey, one starts to appreciate why very few will convert among the 89% in lines 1 through 6 of the table, and why only a disappointing fraction will convert among the best resourced and most highly motivated 11% in lines 7 and 8 of the table.
- Early heat pumps performed poorly in New England winters. Even though new-generation, cold-climate heat pumps perform robustly in New England winters, the heat pump industry still faces skepticism among many homeowners and contractors. (For more information about heat pumps and heat pump installation support, visit this collection of links. )
- The process of implementing heat pumps is difficult for homeowners. It requires a substantial investment of time to learn the vocabulary, sort through the options, negotiate with and manage contractors, and navigate the incentive bureaucracy. (Confirming the reports of constituents, the MassCEC recently estimated a conversion might require 50 to 100 hours of homeowner effort given the limited available coaching resources for homeowners.)
- While there are many inspiring success stories, people often find themselves struggling with complex, partial, and imperfect solutions. Sometimes, without spending large sums on deep home renovations, the design alternatives may be messy and unattractive.
- Some survey respondents backed away after studying heat pumps, and chose to go with efficient gas or oil burners. Many older homes do not have any heating or cooling ducts (more than half lacked ducts in our sample) so they need to install minisplit room units. But it may not be feasible to install minisplit units in all the rooms that need them.
- Many, especially seniors, do not expect to be in their home for the life of a heat pump and are not prepared to make the necessary investment to convert.
- Some are attached to older, less insulated homes with more outdoor air exchange. Similarly, of radiators, “love putting my snowy mittens and hats on the toasty radiator after shoveling!” – the old technology does have appeal.
- The whole conversation can be exhausting: “We are very aware of our environmental impact, and do as much as we can to minimize it, and yes, there is always more to do – but we can’t afford (financially and psychologically) to continue questioning and justifying every single thing that we do.”
- For some, it’s hard to feel good about investing in carbon reduction when others are not doing their part – “throwing cash at money-losing improvements for my own house while the rest of society allows the planet to burn does not make sense.”
- Even among people who are resolute about doing their part to address climate change, fair questions about heat pump conversion can be raised:
- The sources of our electric power are not all green. Several wondered about whether this means heat pumps will not save carbon. Heat pumps are efficient enough to save carbon, even when they are entirely served with electricity generated by natural gas. Additionally, over the lifetime of the pump, the plan is that the grid will become greener, so the carbon savings will grow. See this thread. But to the extent winter gas shortages force electric generators to burn oil, the near-term marginal carbon effectiveness of heat pumps may become a close call.
- Some expressed concern about rising electric rates and grid reliability, especially as we add more heat pumps and electric vehicles. These are valid concerns. We have ambitious plans for the electrical system, but whether those will work out well is another conversation.
- Some pointed out that manufacturing of heat pumps generates carbon. Here is an article on carbon embodied in heat pumps. This article suggests (in section 3.2.2) about 1.5 metric tons embodied in a medium sized heat pump. There are many relevant variables, but this is on the scale of one year worth of likely carbon savings from a conversion. So, yes, embodied carbon is significant and we should take a full life cycle perspective, but that computation only slightly reduces the motivation to convert.
- Finally, it is undeniable that there are other ways to cut carbon that are less expensive, like reducing vacation travel.
- Those who live in larger buildings, whether as renters or as owners, face a complex group decision-making process and, while they may be eager to cut building carbon emissions, they often do not see a practical path forward.
The constituents who care to subscribe to my email list are, on average as compared to the rest of the state, more progressive and more concerned about climate change. The half of my emailing list that chose to respond to the recent survey likely skews further in that direction. Even within this very pro-climate-action sample, it is reasonable to expect that only a low single digit percentage will choose to convert to heat pumps in any given year. The survey results offer no reason to doubt the discouraging statewide potential studies on which Mass Save’s plans are based.
So, it appears that, if we want to deliver on our climate goals, we cannot evade the dilemmas raised by the Commission on Clean Heat report:
- how much to increase upfront incentives for heat pump conversions;
- how to hold down electric bills for people who convert;
- how to fund those increased incentives and electric bill subsidies;
- how to make it much easier for homeowners and other decision-makers to work through the process.
The heat pump narrative rests on the premise that our power generation sources will soon be much greener. We also need to assure that we are delivering on that vision.