Last month Bill McKibben wrote in The New Yorker magazine about a family in Vermont that had insulated its house, replaced its oil burner with electric heat pumps, added solar panels to the roof and, presumably, cut its carbon footprint. It’s a noble concept but I’m not sure it’s working.
Bill and I go back a long way. We took a trip together in September, 1984, to Hydro-Quebec's James Bay plant, then nearing completion, and he wrote about it in March, 1986, in an article in The New Yorker about the various sources of energy for his apartment in New York. I believe it was one of Bill's first assignments for The New Yorker. I was then a reporter at The New York Times and wrote about the project immediately. Both of us have closely followed the evolution of energy and climate science ever since, but our paths have diverged somewhat. Bill is the co-founder of 350.org, which seeks to hold the atmospheric concentration of carbon dioxide to 350 parts per million. (It’s now over 400.) My bet for clean air is nuclear.
I've never met the family he wrote about, the Borkowskis, but I'm familiar with the energy system that they (and I, and Bill) live in. Alas, that system is not set up to take advantage of the changes they've made in their home.
Natural gas and coal. Electrification (as in electric heat pumps replacing oil) can cut the carbon footprint but not always. In this case, an oil burner that was probably at least 80 percent efficient, and possibly 90 percent, has been replaced with a mixture of 34-percent efficient coal, and 60 percent efficient natural gas, minus transmission and distribution losses.
The efficiency of the heat pumps – that is, how many BTUs they provide to keep the family warm, compared to the number of BTUs they pull off the grid—is a complicated question, depending in part on the temperature of the air they’re drawing the heat from. When Vermont gets cold enough, the system will switch to plain old resistance heat, which has a bigger carbon footprint than the oil did. Whatever the efficiency, to meet our national carbon goals, the proper approach is to keep low-carbon sources on the grid.
Solar won't hurt, but its help will be limited. Bill says solar panels can save the utility system from building more central-station power plants by making energy at peak hours. But that happens only if your peak is at noon. In northern New England, peak is likely to be during dark winter nights, when the solar panels won’t do any good. Farther south, it will be late afternoons in summer, when the sun is too low in the sky to be much help. And heavy subsidies for solar can squeeze out other, round-the-clock zero-carbon sources.
Bill says that solar power is the most disruptive energy technology. It might become so – if there is a parallel breakthrough in batteries, which is not now on the horizon – but for now, the energy revolution isn’t solar, it’s fracking. Solar produces about 0.4 percent of our electricity, and natural gas about 27 percent, and rising rapidly. Ten years ago natural gas was 19 percent.
One reason natural gas grows is because it is chained to wind. To keep the electric system stable, adding wind requires adding natural gas turbines, which can start quickly and stop quickly, to compensate for wind’s uneven production. These gas burners are not particularly clean, and not particularly cheap to run, and certainly not zero carbon. But the combination of cheap gas and subsidized wind has pushed down the price of electricity in regional wholesale markets, which is bad news for actual zero-carbon generators, like nuclear.
Solar actually is zero carbon but it collects big subsidies from governments and all utility customers.
I contributed to the Borkowski’s panels, because they got a solar tax credit, and so did every other federal taxpayer. I contribute monthly to my neighbor's solar panels, through my utility bills, by providing what amounts to a cost-free, perfect battery (the electric grid). My neighbor sells energy to the system at noon, at a fixed price, and buys it back at the same price at 5 pm, when his panels produce little but his demand is highest, and when the wholesale price is far higher. In addition, I now contribute more than my fair share for building and maintaining the wires needed to meet his 5 pm peak demand – he pays system charges only on the net kWh he buys.
Bill and I visited northern Quebec at an odd time in energy history. Hydro-Quebec, flush with new capacity, was trying desperately to find new markets for power. But in the Montreal hotel we stayed in at the beginning of the trip, stickers on the bathroom windows asked guests to conserve precious energy.
We are at an odd time now, too. Heat pumps like the ones Bill wrote about could help electricity displace fossil fuels in consumers’ lives. Electric cars would do the same. But if we kill off zero-carbon nuclear, through markets and government policies that don’t recognize its value, then the future will not be as low-carbon as we hope.