This commentary is by Peter Ehrlich of Jericho, a software engineer and founding member of the Zero Percent Club.
Vermont’s electric grid is allegedly 100% CO2-emission free. This is evidenced on the Green Mountain Energy energy mix page, which shows a clear breakdown between hydro, nuclear and solar. Our other smaller utilities follow suit.
That mix takes into account renewable energy credits. Vermont law (fiduciary responsibility to ratepayers) requires that utilities perform what’s referred to as REC arbitrage: Credits are generated by renewable energy such as solar and wind in-state. Some are retired by the project owner, but most are given to the utility. The utilities then sell these to our neighbors (Massachusetts, New York, etc.), while buying cheaper hydro RECs from Canada to bring us to “100% renewable.”
These hydro RECs are cheaper because other states won’t accept them as high-enough quality.
Without including RECs, we get about 10% of our power through “market purchases” at the ISO-NE average mix. We can look on Electricity Maps and see that the carbon intensity of this mix is about 317g/kWh, or 55% “natural” gas, aka methane. Not ideal, but there’s reason to hope that even this 5% of our grid will improve.
With the lifetime of a residential heat pump being 15 to 20 years, we have to consider how the grid will change in that timeframe. To do so, we can look at each state’s Renewable Portfolio Standard. All neighboring states have such standards, including goals to get to 100% by 2050. I happen to have done a deep dive on New York’s energy makeup goals for the next 20 years, and they’re taking it seriously.
On top of this, ReV, VPIRG, 350VT, and others are advocating for an update to Vermont’s Renewable Portfolio Standard this session. This would raise our requirements for clean energy (we are already passing the current standard), raise the amount of in-state renewables (a good move for our electric prices), and limit the amount of REC arbitrage allowed (reducing regional emissions).
All this is to say: Vermont has possibly the cleanest grid in the U.S., and it’s getting better.
Batteries and recycling
A lot of fuss has occurred recently over battery mining, recycling, and so on. There are many companies facing this head-on, including Redwood Materials in California (founded by Tesla’s original founders), Li-Cycle in Rochester, N.Y., and Currents Market in the Pacific Northwest.
The theme I’m seeing is that these companies are ahead of the electric vehicle market — batteries are just not degrading quickly enough yet, but we’ll be ready to recycle them when they do.
Tesla recently produced a report of its vehicles after 200,000 miles, averaging 88% battery retention (only 12% capacity loss). As an EV owner, this wouldn’t concern me even if I was at the 200,000-mile mark — in normal operations, I use only 20-30% of my battery between charging. (I’ve come to believe that the main benefit of a big battery is faster charging stops, not fewer charging stops). Grid batteries would, of course, cycle more intensely, but degrade similarly.
It’s worth looking at the environmental impacts of mining. Hannah Ritchie, the former research lead for Our World in Data, has published a piece going into the demand for mining and ore extraction in a fossil-fuel based world versus a clean energy one.
The bottom line? Even if you assume that batteries and clean tech see no more efficiency improvements in the coming decades, the need for mining is reduced by more than 30% in comparison to our current need for fracking, strip-mining for coal, and so on. (Interestingly, cars become more mineral dependent, but when paired with clean energy generation, the whole system requires less).
Affordability and reliability
For years, construction of fully electric homes in the South has been cheaper than fossil-fuel-based ones, and the competitive developers have defaulted to that for cost savings.
What’s less well known, partially because cold-climate heat pumps have radically improved even in just the past five years, is that the same is true in cold climates. Here’s a 2020 study by the Rocky Mountain Institute that looks at the cost savings of going all-electric (by planning out full demo houses).
The New Buildings Institute has done the same work (slightly south of us in Massachusetts climate zone 5A), and found that an all-electric home comes in $7,500 to $8,200 cheaper. That leaves a margin for backup heat (resulting in no cost-savings on construction) or for a whole-house Generac (about $5,000 plus installation).
There’s also a lot to be said for the price stability of electricity, which is highly regulated and will be going down as renewables drive the cost down, versus fossil fuels (including natural gas), which can be highly volatile.
Making predictions 10 years out is a tricky thing to do, but I think it is highly likely that the increasing effects of climate change will force politicians to cut back on production or otherwise raise the prices of gas — beyond the volatility that is already in that market, thanks to geopolitics.
I don’t think we should make new houses that force people to face either tens of thousands of dollars in upgrades or pay out the nose just for heating.
