Here’s where I came out. We’re a family of 4 living in Denver. I haven’t tracked the exact mileage we’ve driven over the last few years, so I made a reasonable guestimate. I pulled the energy use directly from my bills.
My budget is an attachment to this post. I'd also be happy to share my spreadsheet if it's helpful.
I originally went into this exercise thinking that there would be some habit-changes that I could take on for some small savings. It turns out our prior Mustachian habit building took care of a lot of the “easy” things already. We don’t have much of a commute in the household, as my wife takes the train to work, and bikes to the train station in good weather. I’m mostly a stay-at-home parent, but I do take on an occasional contracting project, which I do from home. I would like to bike to school with the kids more, but that’s largely a function of my 4 year old getting more comfortable on the bike.
Here's the story of what I’ve done, and where I’m at:
1. I bought a home energy monitor to try and optimize my energy usage. This helped me identify a faulty valve in my hot water recirculator that was causing my hot water heater to kick on for 10 minutes every hour. It was using a LOT of energy. I was also able to make some other small optimizations to energy usage.
2. After fixing this issue, I replaced my gas water heater with a heat-pump variety. The combination of these changes should drop the emissions from home energy by over 5,000lbs per year compared with my 2020 numbers.
3. Travel by car and plane is a tricky one. We didn’t travel much in 2020, but we did a LOT of road trips in 2021. I think we’ll do somewhat less in 2022. The kids are at the age where we’re enjoying road trips to National Parks and other parts of the country. We’ve done a pretty good job of eliminating short drives around town. Most of our miles are road-trip miles. There’s also a wedding we’re going to this year that we plan to fly to. Thankfully, a short airline flight doesn’t have quite the emissions impact I feared. This would be different if we were flying a long distance.
4. I started participating in a program with my utility where I pay an additional $0.015/kwh and the utility buys additional wind power to offset my usage. While this does reduce the carbon intensity of my electricity, I couldn’t really quantify it, so I didn’t include it as a benefit. (On a side note, the emissions intensity of my utility seems to be declining at a decent clip, but the latest available numbers are from 2020. There will be some reductions to factor in once better numbers are available).
Long term plans: It turns out that our long-term emissions are primarily driven by a small number of large decisions. My long-term plans are as follows:
1. Eventually switch to an EV. I’m not ready to trade in our cars yet, and now seems to be a particularly bad time to buy a car. But I expect our current cars to be the last gasoline cars we own.
2. We currently have a small solar array that generates slightly under 3,000kwh per year. Our roof has a short life left on it, so I hope to expand the system when we replace the roof. We live in an area with a lot of hailstorms, so I expect this will be related to a home insurance claim.
3. I’d eventually like to switch our gas furnace for a heat pump. There’s no way to financially justify this, but this is ~4,400lbs of annual emissions that there’s no other way to get rid of. This might be something to do if we get into a OMY situation with our FI date.