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Science | The Atlantic
Science | The Atlantic
Get a Heat Pump
If you’re like me, you know that getting rid of your car is one of the best things you can do for the climate, and also that you will never do it. This is a car-oriented country, and a car-oriented time. But in 2019, the private cars and light trucks that ordinary people drive for work and shopping and leisure were responsible for about 15 percent of U.S. fossil-fuel-energy use. Electric vehicles get a lot of press, but less than 1 percent of energy used for transportation came from electricity. Personal transportation is a large contributor to carbon emissions in America; it’s also the hardest to give up.But trading a gasoline automobile for an electric one (or for a bus or train) isn’t the only way ordinary citizens can contribute to fossil-fuel reduction. Decarbonization has two pillars: First, generate electricity from energy that does not emit carbon—renewable sources such as wind, solar, and geothermal instead of fossil fuels. That requires legislative and regulatory change. Second, use electricity to run as much of your personal life as possible.That’s where ordinary people like you and me can contribute. At least 7 percent of U.S. fossil-fuel energy is used for something fairly banal: residential space and water heating. Put differently, making relatively smaller, cheaper, and easy changes to home heating in America could reduce fossil-fuel use nearly as much as taking half of all private vehicles off the roads. If you want to do the most immediate good for the planet, replace your aging gas furnace with a new, electric appliance.You can heat a building in many ways. A boiler heats water and cycles it through radiators that heat rooms. A furnace transfers heat to air, which it then pushes through vents into living spaces.Most American homes run these devices by burning fossil fuels. Depending on your geographic location and the age of your home and its systems, those fuels might include distillate fuel oil (mostly still used in the Northeast), propane (common in rural areas), or natural gas (common everywhere else). Every one of these releases carbon dioxide into the atmosphere when burned.But boilers and furnaces aren’t your only options. Instead of heating the air, heat pumps move heat from one place to another by converting a substance called refrigerant between its liquid and gas forms. Your refrigerator is a heat pump. So is an air conditioner. Both of those devices pump heat in reverse: Warm air is absorbed by the refrigerant coils and pumped out. Your fridge and AC unit move heat in only one direction. But a heat pump can do both, meaning that the same appliance can heat in the winter—even in very cold climates—and cool in the summer. (“Heat pump” is a terrible, confusing name for these gadgets.)Heat pumps have been around for decades, but they didn’t used to be very efficient, especially in extremely cold weather. That’s changing. Now some cold-climate heat pumps can transfer heat effectively in subzero temperatures. An oil- or gas-fueled furnace (or other backup heat sources) might be required on the coldest days, but on all the others, your heat can be electric.In Maine, the lack of natural-gas infrastructure made it easy for the state to encourage electrification of home heating. Central air is uncommon in the state, and installing a heat pump adds cool air-conditioning for free. Maine’s electricity grid is already very clean, and these new heat-pump devices are much more efficient than window AC units.Michael Stoddard, the executive director of the Efficiency Maine Trust, the state’s energy-efficiency organization, told me that more than 60,000 heat pumps have been sold to Mainers in the past seven years. Some Mainers have been burned by the high cost of heating oil, a commodity whose price fluctuates. State-sponsored consumer-rebate programs, including one that offers up to $1,500 back on purchases of heat pumps, has also driven recent adoption of the devices. Stoddard worried that participation in the state’s incentive programs might dry up because people wouldn’t want to spend the money during the pandemic. “Instead, participation has doubled,” he said. People were stuck at home, some with extra money to spare, given their stimulus benefits and reduced spending. And parts of Maine can still reach 90 degrees Fahrenheit in the summer.Does carbon reduction itself motivate Mainers to adopt heat pumps? “I’m confident the answer is that it is evolving,” Stoddard hedged. But even if residents aren’t making green-energy choices with decarbonization in mind, the success of incentive programs such as the Efficiency Maine Trust’s have helped the state advance more aggressive policy proposals. In the weeks prior to our conversation, Stoddard told me, Maine had just completed a new climate action plan, and decarbonizing heating systems was among its top three mitigation recommendations. “Now you have everybody talking about this as if it’s just a thing we have to get going on,” he said.Elsewhere, switching to a heat pump is a tougher sell. Natural gas pollutes less than distillate, and it doesn’t suffer the commodity-price fluctuations that have helped shift homeowners off heating oil in the Northeast. And more than 60 percent of the U.S. residential market already has air-conditioning, according to Paul Camuti, the chief technology and strategy officer at Trane Technologies, which manufactures HVAC systems. That means the benefit of added air-conditioning from a heat-pump switchover doesn’t apply to many American homeowners.Even so, electric utilities have strong incentives to move homeowners to electric heat: They can sell them more electricity, for one thing. And they can realize their own decarbonization goals more rapidly. For both of these reasons, the Sacramento Municipal Utility District (SMUD) in central California has adopted some of the country’s most aggressive rebate incentives for heat pumps, as much as $3,000 on heat-pump space heaters and $2,500 on heat-pump water heaters. According to Scott Blunk, SMUD’s strategic business planner of electrification and energy efficiency, the incentives can make the payback almost immediate.The water-heating program has been the most popular, probably because the incentive provides the most benefit at the lowest cost to homeowners and contractors. Electrifying water and space heating is still unfamiliar to many people, and Blunk speculated that giving them a reason to try the technology might warm them up, as it were, to other gas-to-electric conversions. Heat-pump space heating is entirely viable in central California, where the temperature doesn’t drop below freezing that often. Even without the incentives, replacing an air-conditioning unit and a furnace with one heat pump can save a lot of money in the long run, since the heat pump can do the job of both.As was the case in Maine, Sacramento is leveraging the success of its electrification programs to shift corporate strategy and state policy. The energy code for 2023 is currently being developed in California, and it is making the rollout of electric devices easier. Adjusting the baselines of reasonable energy need can make room for electrifying more home devices. And making electric-appliance installations easier for builders encourages them to recommend cleaner appliances. In addition to reducing carbon emissions directly, every heat-pump installation has an incremental effect on the viability of policy changes.You don’t have to get rid of your old appliances right away, either. “To hit our decarbonization goals, we don’t need to take out someone’s perfectly good water heater,” Blunk told me. “We just need to replace it with an electric one when it goes out.” That’s an easier pill to swallow for homeowners, who can think of the incremental cost of electric conversions as a small premium over the money they were going to spend on a replacement device anyway. Rebates and incentives sweeten the deal.Sacramento power burns no coal, and runs roughly 50 percent carbon-free, thanks in large part to hydroelectric power. Blunk calculates that a new-construction home on the grid might reduce its carbon output from 2.5 to 1.1 tons of carbon a year, and a 1978 home’s could drop from 5.2 to 2.5 tons. Because 80 percent of the region uses natural gas for space and water heating, electrification could substantially reduce fossil-fuel use there.Unfortunately, many Americans still don’t trust electric and renewable sources for heating. Some blamed Texas’s widespread outages during a severe storm this month on the failure of wind turbines, but that’s not right: The state still relies largely on natural-gas energy for electricity. And even gas-burning furnaces require electricity to work, making those appliances no less unreliable if the power goes out for an extended time, as it did across much of the state. Amid climate change, gas isn’t an answer so much as just another problem. “Electrifying buildings and vehicles while switching to climate-safe clean electricity while adapting our infrastructure to a changing climate will be deeply challenging,” David Pomerantz, the executive director of the Energy and Policy Institute, told me. “But relying on gas in a changing climate would also be deeply challenging.” Electric power is fundamental to everything we do, making widespread reform of the grid and the tools that use it even more urgent. Instead, we expend energy glorifying electric cars. For this year’s Super Bowl, General Motors spent millions on a star-studded ad celebrating its ambitious electric-vehicle plans. It was surprising, but not out of place. Less surprisingly, no heat-pump ads aired during the big game. Even if trust in the grid can be improved, electric heat faces one big problem: Transitioning off natural gas just isn’t as sexy as solar panels or electric cars. Unless you’re a contractor or an HVAC nerd, you probably don’t think much about your heating and cooling systems. They are hidden in attics and basements and utility closets, tucked away on roofs or in side yards. These machines go almost entirely unconsidered unless they break down. Nobody shows off their new water heater when friends come over the way they might show off a Tesla in the garage.Unlike solar panels, clean upgrades to home appliances also don’t produce social-signaling benefits—the neighbors can’t gawk at your greener home, and you can’t take pride in passersby noticing it. How do you make a heat pump sexy? “I don’t know,” Blunk admitted. “I think the closest we have is cooking.” He means the blue flame of a stove, the only place in the home where a resident can see and hear and feel natural gas at work. Stove-top cooking is so essential to justifying home gas service, the fossil-fuel industry has poured resources into preserving the appliances’ appeal.Even SMUD’s executives felt protective of kitchen gas. “You’re never going to get rid of my gas stove,” Blunk recalled them saying. So he bought them portable induction-cooking units (a kind of electric stove that transfers heat directly to cookware) to demonstrate that modern electric cooking heat wasn’t like the old wire coils they might remember from the 1950s.Natural-gas cooking is responsible for only 2 percent of residential natural-gas use—far less than space and water heating. Still, converting from a gas cooktop to an electric-induction one can have a substantial, if different, impact. For one part, there are health benefits: Igniting open-gas fires in your home produces pollution that can exacerbate asthma. But from a sustainability perspective, the kitchen is the place where people develop an emotional relationship to natural gas. The blue flame lapping over the sturdy cast-iron grates imparts a sense of power and control to cooking, just as the rumble of a carburetor on a muscle car does to driving.That makes the induction cooktop the Tesla of the natural-gas-decarbonization movement. It’s the device you can brag about while also showing your friends and family that electricity is just as good as gas for cooking, if not better. “When I first got my induction,” Blunk told me, “I had a party and invited all my friends over.”Brian Keane has built a whole organization around that idea. SmartPower, a nonprofit renewable-energy outreach and marketing company, helps municipalities and utilities get their citizens and customers interested in clean energy. “Americans listen to what friends and co-workers are doing. That’s the pressure point,” Keane told me. And when it comes to energy, once you’ve taken action, whether that be installing a smart thermostat or replacing a combustion furnace, the best thing to do is tell a friend or colleague that you’ve done it. This is particularly important for renewable energy in the home, Keane said, because no brand name is associated with it. Nobody knows what furnace or water heater they have. “There’s no Coca Cola, no Pepsi.”SmartPower has run a series of marketing campaigns for solar adoption around the country, many of which amount to better-funded and more-formal versions of Blunk’s induction-stove house party. Sometimes they hold block parties when the panels go up on the first roof in a neighborhood, or host house parties with a utility-bill reveal (really!). People used to want to wait for a technology to be widespread, but Keane thinks that lifestyle-technology turnover has entered the home. “Apple is always coming out with a new iPhone,” he tells homeowners; a water heater is no different. “You could keep waiting, or just buy this one. It’ll work for 20 years.” Averaging across campaigns, SmartPower’s solar programs were found to increase the rate of solar adoptions in a municipality by nearly 1,000 percent.Camuti, the Trane HVAC-equipment executive, agrees that the change in perception about heating and cooling in the past decade has been dramatic. “I relate this directly to the availability of online information,” he told me. People still ask dealers, tradespeople, or contractors what they should buy, which makes upstream incentives from states and utilities to those agents extremely important. “But people go online and ask if there is a better choice,” Camuti said. “We are starting to have a relationship with them.”There are some lessons for homeowners. First, there is benefit in advocating for home upgrades on your block, at your workplace, and in your family. Some people are interested in clean energy for its own sake, but many more are motivated by doing something beneficial for their communities. And emissions reductions positively impact a local environment before the global one. Second, lower-impact but more-visible upgrades, such as induction cooktops or solar water heaters, might become the gateway to abandoning natural gas. Nobody thought they wanted or needed an internet-connected thermostat before Nest came on the scene, after all. But it was stylish and functional, and many smart-home rollouts began from that unlikely start.If you’re building a new home, it’s easier to skip natural gas entirely. Not running a gas line will save thousands of dollars, and it will prevent you from ever installing gas-burning appliances. But for existing homes, you should abandon the idea that a solar roof or an electric car is the only path forward. Replace your gas cooktop and show it off to friends, or on Instagram. Blog or podcast or post on Facebook about it, so that human experiences will come up in search results when people go hunting for their own products. If your gas furnace or air conditioner or water heater is near the end of its lifespan, replace it with a heat pump. And if not, plan to do so when it conks out. If you live in a large population center, do these things sooner, because your action will send faster signals to utilities and governments that the tide is turning. If you want to do your part to reduce carbon emissions, do what you can to wean yourself off the gas you use in your home, not just the kind you put in your car.
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A Golden Rule for a Semi-Vaccinated World
The past 11 months have been a crash course in a million concepts that you probably wish you knew a whole lot less about. Particle filtration. Ventilation. Epidemiological variables. And, perhaps above all else, interdependence. In forming quarantine bubbles, in donning protective gear just to buy groceries, in boiling our days down to only our most essential interactions, people around the world have been shown exactly how linked their lives and health are. Now, as COVID-19 vaccines rewrite the rules of pandemic life once more, we are due for a new lesson in how each person’s well-being is inextricably tangled with others’.This odd (and hopefully brief) chapter in which some Americans are fully vaccinated, but not enough of us to shield the wider population against the coronavirus’s spread, brings with it a whole new set of practical and ethical questions. If I’m vaccinated, can I travel freely? Can two vaccinated people from different households eat lunch together? If your parents are vaccinated but you’re not, can you see them inside? What if only one of them got both shots? What if one of them is a nurse on a COVID-19 ward?After asking four experts what the vaccinated can do in as many ways as I could come up with, I’m sorry to report that there are no one-size-fits-all guides to what new freedoms the newly vaccinated should enjoy. Still, there is one principle—if not a black-and-white rule—that can help both the vaccinated and the unvaccinated navigate our once again unfamiliar world: When deciding what you can and can’t do, you should think less about your own vaccination status, and more about whether your neighbors, family, grocery clerks, delivery drivers, and friends are still vulnerable to the virus.The COVID-19 vaccines are fantastic. The shots that are currently available are tremendously effective at protecting the people who get them from severe illness, hospitalization, and death—all the things we want to avoid if we have any hope of fully reopening society. Even so, advice on what people can do once vaccinated gets complicated. Those who are vaccinated can still be infected by, and test positive for, SARS-CoV-2; they’re just way, way less likely to get sick as a result. The sticky element is whether not-sick-but-still-infected vaccinated people can spread the virus to others and get them sick. So far, the early data have been promising, showing that the vaccines stop at least some transmission, but the matter is not scientifically settled.[Read: The one area where the U.S. COVID-19 strategy seems to be working]This leaves us in an awkward situation. Getting vaccinated means that your choices no longer endanger you much, but they still might make you a risk to everyone else. To put this in more concrete terms: If a vaccinated person goes out to eat, they can’t yet be sure that they’re not carrying the virus and spreading it to their unvaccinated fellow diners and the restaurant staff, or that they won’t pick up the virus at the restaurant and bring it home to their unvaccinated family.So, first, a very broad guideline for navigating a world in which vaccinations are rising and infections are dropping: Whether you’re vaccinated or not, how much you can safely branch out in your activities and social life depends on the baseline level of virus in your community. You can imagine that, in pandemic life, each of us has been dealt a certain number of risk points that we can spend on seeing friends outside, going to work, sending the kids to day care, and so on. If you or someone you live with is especially vulnerable to the virus, you might choose to spend fewer points by getting groceries delivered; if you live alone in an area where very few people are sick, you might choose to spend more points by forming a bubble with friends. The vaccine delivers you a huge number of bonus points, if you’re lucky enough to get one. And when spread of the virus is low, everyone gets more points.Saskia Popescu, an infectious-disease epidemiologist at George Mason University, told me that everyone, vaccinated or not, should try to keep track of three metrics in your area: The number of new daily cases per 100,000 people, the rate at which people transmit the virus to one another, and the rate at which people test positive for the virus. Popescu said that there are no magic numbers that would immediately bring the country back to pre-COVID life, but she’ll feel better about reopening when we hit daily case rates of just one to two per 100,000, transmission rates of .5 or less, and test-positivity rates at or below 2 percent. (As of last week, no U.S. state had reached the trifecta, and the country as a whole is still far from it.) Many local public-health departments regularly provide these numbers.[Read: A simple rule of thumb for knowing when the pandemic is over]You might be tempted to factor vaccination rates into your safety equation too, but Whitney Robinson, an epidemiologist at the University of North Carolina, told me that those numbers shouldn’t be anyone’s main safety indicator. That’s because vaccine distribution so far has been concentrated in particular social networks (for instance, health-care workers) and demographic groups (notably the white and wealthy), so an entire community won’t necessarily reap the benefits that a local vaccination rate of 15, or even 50, percent might imply.Knowing the overall risk of infection in your area is at least a first step toward making better decisions about whether you should host that birthday party or take Grandpa out to lunch. Even for people who are vaccinated, all of the public-health experts I spoke with emphasized, it’s still important to not throw caution to the wind. If vaccinated people flock to indoor restaurants or go unmasked in a crowd, they’re not just risking infecting others if they can indeed spread the virus, Popescu said. They’re contributing to a sense that life as we knew it before March 2020 is back, despite the fact that more than 65,000 people are still contracting the virus each day. Simply returning to our old habits would be deadly.That doesn’t mean that any loosening up is off the table for the vaccinated. Far from it—plenty of public-health experts have argued that vaccinated people safely seeing relatives or returning to the office can benefit everyone, because seeing how much the shot improves life will persuade more people to take it. Downplaying the vaccines’ success could discourage people from getting them, because if it won’t change their lives, they have no incentive.The best way forward for us all is for vaccinated people to spend their extra risk points in ways that don’t put unvaccinated people in danger. As you consider whether you should do things that you wouldn’t have done before the vaccine, think creatively about how you can make those things safer for everyone involved. “Grandparents really want to be able to go hug their grandchildren,” Tara Kirk Sell, a senior scholar at the Johns Hopkins Center for Health Security, told me. “I don’t have a problem with that.” But consider asking Grandma and Grandpa to wear masks during that hug, or meet you outside, or avoid sleeping over. Throughout the pandemic, we’ve developed an arsenal of strategies to make particular settings and activities safer. The vaccine is an extra-strong weapon against transmission that some people can deploy, but that doesn’t mean they need to discard all of the other ones to use it.[Julia Marcus: Vaccinated people are going to hug each other]How many of those methods you choose should depend on how many vulnerable people you regularly come into contact with. A vaccinated oncologist who lives with her immunocompromised sister is going to behave differently from a vaccinated retiree who lives alone. That said, there are plenty of settings, such as restaurants and stores, where you don’t know or can’t control how many vulnerable people are around you. For that reason, small private gatherings where you can adjust your anti-spread tactics to accommodate everyone’s risk factors are a safer first step toward normalcy than activities such as concerts, indoor dining, or big weddings. Travel in small groups might be a nearer goal, too: Popescu said she hopes that by the end of the year, she can take a vacation in another state with her husband without worrying that she’s “being a bad steward of public health.”Playing it safe, even as you loosen up a little, is the best way to ensure that someday, you will again live in a world with bars and birthday parties and movie theaters. It’s also the best way to keep yourself from getting sick with COVID-19 in the future—regardless of whether you’re already vaccinated. No one knows exactly how long you’ll be protected against serious illness if you get a vaccine (or were previously infected), simply because no one has been vaccinated for more than seven months yet. Given what we do know so far, the most likely way for a vaccinated person to get seriously ill from the coronavirus would be if they encounter a variant that the vaccine they received doesn’t effectively protect against. Such variants are much more likely to emerge if the virus is allowed to rage in particular places or groups before the overwhelming majority of the world’s people can be vaccinated.As Gregg Gonsalves, an epidemiologist at the Yale School of Public Health, put it, “In the context of epidemiology, we’re all in the same boat.”
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