Reducing carbon emissions has become an overarching motivation for us on the home front. My wife, Jerelyn, and I have now been through almost two complete winters in our largely rebuilt, early 1800s home in Dummerston, Vermont. There are some things we would have done differently with the house, but we are totally happy with our low energy use intensity and our overall energy consumption.
With more than a full year of data, we are clearly operating in net-positive-energy territory. During the 12-month period from November 2014 through October 2015, our all-electric, 1,500 ft2 home consumed 8,744 kWh, and our 12 kW solar array generated 12,457 kWh. (That span includes the very cold 2014–15 winter, and our solar array was covered with snow for almost all of February.)
Our net energy production was roughly 3,700 kWh. We burned a little wood as well, but not much. I started last winter’s heating season (in the fall of 2014) with a full cord of dry split wood (14" length to fit into our tiny wood stove), and two heating seasons later, we still have about three-quarters of that cord left. I think we only lit the stove twice this past (unseasonably mild) winter. Our single air-source heat pump (18,000 Btu/hour) is keeping us warm, and our heat-pump water heater is providing all the hot water we need.
To make use of that excess solar production, Jerelyn and I purchased a 2016 Chevy Volt at the end of last year. I’ve calculated that our excess solar production will power about 9,000 miles in our Volt—much more than our around-town driving. So far, we’ve been using about 210 kWh per month charging the Volt (296 kWh in the most recent month).
I believe that we will still have enough extra electricity to power a cold storage room for our farm, which I’m hoping to build in the barn this year.
The big nut still to crack, for Jerelyn and me, is our out-of-town driving and—especially—flying. We’re trying to fly less; and when we do fly, we plan to start purchasing carbon offsets. Offsets aren’t as good as not generating the carbon emissions in the first place, but they are much better than doing nothing.
When I fly to speak at conferences or participate in meetings, I’m now requesting that the sponsors or clients pay for carbon offsets. When that doesn’t work, we will buy the offsets ourselves. We are still researching carbon offset options but are likely to go with Native Energy, a Vermont company that has a good track record in funding real projects that are effectively offsetting carbon emissions.
Our goal with all this is to achieve net-zero carbon emissions in our personal lives—to demonstrate that it is possible. Vermont has a goal to get 90% of its energy from renewable sources by 2050, and we want to show that it’s feasible to get pretty close to that goal today.
Hey Alex, Great work here. I still cringe at the transportation picture. Not just the flying and offsets, but the purchasing of a new car to enable net-zero living. The energy to make that car (or any electric car) is substantial and I wish we focused much more on planning and sprawl issues alone. I strongly feel that real net-zero living is eliminating cars from 90% of our lives.
John, I can't disagree that a more environmentally responsible option than buying a Volt would have been to ditch the car altogether. We weren't ready to go that far. I contend, though, that trading in our 13-year-old Honda Civic Hybrid with 195,000 miles on it for a plug-in hybid that we can mostly charge usng solar power was a much better option than trading it in on a new 100% gasoline-powered car, even if it was a reasonably efficient hybrid.
That said, Jerelyn and I still try to bike the seven miles into work in good weather.
Taking small steps is better than not taking steps at all.
John, we don't typically look into LCA issues of vehicles (we focus on building products), but this is an interesting perspective from an NGO I deeply respect on a number of issues. The takeaway: "While recent research suggests the additional components required for EVs (e.g., large battery storage) increase life cycle emissions, the increase is not sufficient to negate the environmental benefits of EVs over their lifetimes." So ... not negligible, but, unlike a gasoline car, an EV has a chance to pay its emissions back over time rather than just producing more.
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