Earlier this week I profiled my friend Dave's greenly remodeled house. (Take a look [0].) Today, Dave tells us about some of the decisions he made in the process, and why sailing is the key to green living.
How did you get started with green thinking?
In 1999, I was a recovering dot-commer. I bought a boat, sailed around, and that’s sort of how I got into the green stuff. Living on this little power island – I had solar electrics and wind, I was living on really limited tankage, like 36 gallons of diesel, and 100 gallons of water. So I learned about photovoltaics [1] and wind [2], and how to manage an energy budget. I had been reading A Roadmap to Natural Capitalism [3] that year, and I thought it was really cool, so I started stalking Amory Lovins [4] – at a conference in 2000, I stood up at the Q&A and asked him for a job. I ended up getting an internship at Rocky Mountain Institute [5], met all the green building gurus, and joined the Natural Capitalism consulting practice – the book had just come out and the phone was starting to ring with people asking, “How are we going to implement all this?”
What was the house like when you bought it?
It was originally built in 1999. Most of the house was already built when we bought it in December 2005. (We moved in February 2007). We refinished the floors in water-based finishes, we painted every surface, and we put all these systems in – solar, AC, heating. The house was already really well thought out for daylighting. During the day, you don’t need to turn on the lights at all. Mark Burget built it; he used to run the Nature Conservancy [6] in Colorado. This was his dream house; he did a lot of original design for it: the greenest and most durable that he could come up with from the Nature Conservancy mindset. Which meant certified hardwoods, lots of recycled materials and durable materials, but no energy efficiency whatsoever.
Why did you decide upgrade the energy efficiency?
It sounds a little paranoid, but we like the security. Since my fiancee Helen and I have a little bit of extra resources now, we like the idea of buying all our energy supply up front. I mean, we’ve been getting boiling water with the [solar-vacuum-tube-and-tank setup [6]]. It’s a $40,000 setup, once you factor in the [800-gallon, custom fabricated] storage tank, pumping, tying it into our hot tub; we didn’t do it on the cheap. But we feel really good about paying for it up front, because now we’re totally unexposed – essentially totally unexposed – to energy cost fluctuations. And we’ve been able to unplug from the addiction to natural gas, which is just not sustainable. We’re not burning anything anymore. So there’s that environmental thing, but I think the energy security is the biggest aspect. If you can do it now, buy it all up front, because there’s a lot of uncertainty.
In addition to the energy security aspect, what are some of the payoffs for you?
You know, our project manager for the house was a guy named Drew Lindsey; he’s in his mid-20s. All this green stuff we‘ve been talking about – low-VOC or no VOC paints, sustainably sourced materials – all these conversations we’ve been having with him, he got really into it, so he joined Boulder Green Building Guild [7], started doing a LEED [8] course, and now he’s bringing all this into conversations he’s having with his other clients. That’s a big impact.
With things like the solar photovoltaic awning [8], we wanted integrate it so you could see it. Is it “impress your friends”? Well, probably, a little bit. And I think it adds some function, it adds some beauty. But we also want to put the signal out there. We do a lot of fundraisers here – Global Fund for Women [9], Global Greengrants [10] – or even just parties or movie nights: We want to show the world that solar works, that it’s not a big deal, that it can be cool-looking. We want to get that conversation going.
It is a cool awning.
This is only the second installation in the U.S. of this type of panel – the other guy is one of the authors of Amendment 37 [11]. The solar cells are sandwiched in clear glass, which lets enough light through to allow daylight but cut some of that direct solar loading of the office space. The cells are two-sided, so whatever light does get through and is reflected back gets picked up on the bottom as well. It’s like a solar calculator – you don’t need direct sun, you just need light.
Essentially what we did was install an uninterruptible power supply [12] in our workshop/studio, where all the important stuff happens: all our computers, Internet, servers, all that is backed up on that circuit. There are six batteries stored there. And we pulled a couple of critical wires over from the main house: the fridge, the pumps for the heating system and the solar. So if the grid goes down, you’ve got solar battery backup for the studio that’s automatic, with all the critical circuits backed up.
Have you run the numbers on your system?
I finally ran a scenario in PV Watts [13] to get a more accurate estimate for our PV system output, and the "85 percent" of our house's load I had originally told you is optimistic but, well, still possible.
A conservative estimate of our PV system output (calculated for our latitude and longitude, weather, tilt of panels, etc.) is about 4,300 kWh per year. This would correspond to about 91 percent of our lowest electric bill. But here's the real kicker: We've added a few new pumps to move hot water and filter the hot tub, and while they're as efficient as possible, they'll probably tip us over the highest estimate for electricity use, even though I've been aggressively changing out lightbulbs to CFL [14]s, et cetera.
So I'm thinking our PV array will cover somewhere around 40 percent of our loads this year. Alas, it's time to get really serious about dropping electric loads further, and probably add a PV array on the back of the property – to the tune of another 3 kilowatts – if we are really going to be net-zero [15].