We were chattering away on the Roadtrek Facebook group about solar, and it got me to thinking – what is my energy consumption and carbon footprint now that I’m fulltiming compared to when I was still living in a sticks and bricks house? I know I’m using less, but I never sat down and estimated it. Let’s see what we can figure out from the data I have.
One thing I discovered after a year or two of fulltiming was that I drive almost exactly as many miles per year as I did when we were living in a house. This may seem surprising, but think about it. Soon after we got the Roadtrek Sharon discovered how much more comfortable and convenient traveling in the Roadtrek was than a regular car, so we pretty much parked the car, and went everywhere in the Roadtrek – my work commute, family visits around the state, plus two marathon vacations a year. Total was about 16,000 miles a year. Now that we’re fulltiming, we do one long lazy loop around the continent and end up where we started – in Florida for the holidays. Again, the total is about 16,000 miles a year. We see much more countryside than before, but our travels are all one way – we don’t zoom out and back like when we were stationary. Therefore, vehicle fuel use is a wash.
And how much fuel is that? I average about 13 miles per gallon, counting city driving and idling, so 16,000 miles is 1230 gallons, or 24 barrel oil equivalents of fossil fuel energy. I’m going to calculate everything in barrel oil equivalents so we can compare it easily.
Now, let’s look back, not too fondly, at my utility bill for the last year I was sedentary. We lived in a very stylish but not too well insulated bungalow, so our bills were painful. Through the tears as I read my old spreadsheet, I can see we used 14,000 kilowatt-hours. If I try to estimate my use at work, figure half the house use was mine, and I spent about a quarter of my life at work, unfortunately, so add an eighth to the total, and that’s 15,750 kilowatt-hours. To get barrel oil equivalents, figure one barrel oil equivalent is 1700 kilowatt-hours, so that’s 9.2 barrels of oil worth of energy. Gas-fired electricity plants, which I was being served by, are around 55-60% efficient, so it took 16.14 barrel oil equivalents to produce that 9.2 barrels worth of energy. Oil and coal plants are about 30-35% efficient, so triple your electricity to find out how much fuel it took to make it. That’s right, even with the most efficient generation system I used about two-thirds as much energy in my sticks and bricks home as I did driving around. You never see the coal/oil/natural gas you use at home, because it’s all converted to electricity, but it’s still there. A lot of it.
I plug in maybe three or four months a year now, almost all of it driveway camping in Florida visiting my family, but my energy use is very low compared to the environmental disaster that was my old house. Luckily, I have cumulative solar data from the summer months, when I live entirely on solar, and that’s about 1727 kilowatt-hours for four years, or 72 kilowatt-hours per month, so say I plug in for a total of about 250 kilowatt-hours a holiday season. That’s less than 26% of a barrel of oil. I also buy much more propane now that I’m fulltiming – maybe five gallons every two weeks. That’s 130 gallons of propane a year, which is another two barrels of oil, roughly. Probably less, since it’s much lighter and less energy dense, but I’m feeling generous.
So my total fossil fuel energy consumption back when I was living in a sticks and bricks house was 40.14 BOEs (barrel of oil equivalent), and now I’m using 24 barrels for vehicle fuel plus 0.26 for store-bought electricity plus a couple more for propane – 26.26 BOEs. That’s pretty close to 65% of my previous fossil fuel use level; a 35% reduction. That, as we say in scientific literature language, is a significant difference.
I love this planet – that’s why I’m out driving around looking at it, instead of sitting in a sticks and bricks house, burning up too many of its resources. Plus, I have MUCH more fun this way 😉
edit: I forgot all about the natural gas i heated with back in my sticks and bricks house – you’d think if I paid $994 a year for something I’d remember it. I was probably paying lower than the current $1.33 per hundred cubic feet (CCF) back then, but even using the current rate, that’s 710 CCFs. 58 CCFs is one BOE, so that’s another 12.24 barrel oil equivalents I used to use and don’t anymore. that means my old BOE total is 52.38 compared to the present 26.26, which means i am using energy at 50.13% of my old rate.
Half. That’s easy to remember.