An Open-Source Core and a House That Unfolds Among Innovations at Solar Decathlon

Student teams showcase energy-efficient home designs at the 2013 Solar Decathlon

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Tekla Perry: Hi, this is Tekla Perry for IEEE Spectrum’s “Techwise Conversations.”

College students, as we all know, have lots of energy—energy enough to stay up all night and still get to class during the day. If you could harness that energy, you could power a small city. Well, we haven’t quite figured out how to do that, but what if you took some of that energy and put it toward building solar-powered, energy-efficient, attractive, and cost-effective houses? Some innovative things just might happen.

That’s the intent of the Solar Decathlon, a program run by the U.S. Department of Energy that challenges teams of college students to create solar houses. They have two years to design and build their entries—and then they have to take them apart, truck them to the competition site, and reassemble them for judging.

The teams of the 2012–2013 Solar Decathlon competed for sunlight and the judges’ attention last month in California’s Orange County Great Park in Irvine. Solar Decathlon director Richard King was there. He holds a physics degree from the American University and has been with the U.S. Department of Energy since 1986. He created the Solar Decathlon in 1999 and has run it ever since.

Hi, Richard. Welcome to the podcast.

Richard King: Hello. I’m delighted to be here.

Tekla Perry: So let’s jump to the finish line: Who won?

Richard King: Team Austria. It was the Vienna University of Technology, which came all the way over from Europe. They designed and built an exquisite house that was really designed for kind of a vacation home for a single couple. It was exquisitely built; the craftsmanship was wonderful. They focused on a lot of wood products inside the house to be kind of carbon neutral. It just stole the judges away. It also performed quite well, so it eked out a narrow, narrow win over the other teams.

Tekla Perry: So let’s go back to when this whole competition got started. How did that come about?

Richard King: The Solar Decathlon got started in the year 2002, was our first competition. But you’ve got to back up to 1999, when we had the idea. We had developed at the U.S. Department of Energy very robust and reliable solar panels and solar photovoltaic products, but they weren’t being sold in the marketplace that well. And so I just really felt that we needed to get out of the R&D mode and get more into the education and the outreach side of things to really make the market grow.

But I’m a physicist. I needed help from the architects. I really felt that if we could design houses that were really cool, really awesome, looked really nice, as well as being reliable, then people would be more accepting of them and the market might grow.

So I went to the university community, challenged the schools of architecture and engineering to take a clean sheet of paper: “You guys, start from scratch, design a home, and let’s see who can design the best one, make a competition out of it.” So it ended up being just such a win-win, because now we’re educating young professionals who–our schools, our universities, are the innovators, and the great ideas, and they in turn can help educate the professional community that, “Hey, there’s a new building product in town: Solar systems can be used to help you build a house,” and to get them integrated in it.

And lastly, it made a spectator sport out of it, so to speak. Let’s not just design these on paper. Build a house, a full-scale house, bring it to a central spot, and open it up to the public. Let the homeowners go in. Let people go inside and see these houses, see how they work, and break down those barriers, that, yes, it does look good. Yes, it can supply all the energy we need from sunlight without sacrificing lifestyles. These are modern homes with everything you would want in them. It’s just been a win-win ever since. People come out in droves to see them, and students get educated, and everybody gets educated.

Tekla Perry: How many houses did you have this year?

Richard King: We had 19 show up, although we started with 20 homes. In the first competition, we had 14 pioneering schools who came to the National Mall and set up. Ever since, we’ve moved it up to 20 teams—always been 20, don’t want more, don’t necessarily need less. So 20 schools signed up, and we had one school drop out a month before the thing. So those students got educated, that house is still built on campus, but they ran out of money at the end to bring it all the way to California.

Tekla Perry: And these came from all over the world?

Richard King: Yes, we opened up internationally. We had two Canadian teams, and we had two European teams.

Tekla Perry: You gave awards in a number of categories, not just the overall winner, and one of those was engineering, which I saw went to Team Ontario. Can you tell me about that design?

Richard King: The decathlon gets its name from 10 contests, and how do you evaluate a house? How do you measure a house for performance? We sent juries through—architects for architecture, engineers for engineering, there’s market appeal, and also communications.

When the engineers go through, they look for design excellence. Is the whole house integrated well? Are the systems picked out to work reliably together? Things of those natures. So, yeah, this house was just very well designed. Everything fit. It was Team Ontario, correct? Yeah, the judges felt they took an extra measure of professionalism in that house. It was one of my favorites. I loved that house.

Tekla Perry: So as you walked through the various entries, and I’m not just talking about the winning ones, I’d love to hear about some innovative elements that really struck you, that was, “Wow, I can’t believe they thought of that,” or “It was a really striking invention that they had there.”

Richard King: There were a lot of them. So the one that stands out, certainly from the popular side of things, was the SCI-Arc/Caltech—so that’s the Southern California [Institute] of Architecture, SCI-Arc, teaming with Caltech. And they put their house on rails. They had it open up and create this big interior space, and it was movable. They could—they had controls in the house to do this.

One of the design challenges of the Solar Decathlon, because they are relatively small houses—they are between 600 square feet and 1000 square feet, so they have kitchens and living rooms and bathrooms and a bedroom, quite livable space, but yet one of the objectives is to create a larger feel to the house, because it is a relatively small house. So SCI-Arc/Caltech decided, “Let’s take a square box, cut it down the middle, and open it up.” They had a telescoping solar system on the roof that would just slide in and out and stay up over as a kind of a canopy, and they had kind of a garden set up underneath the house, so as it opened up, you could just walk around and stand like you would on a porch, only it was on the interior of the house. So everybody lined up to watch the house move, open and close, and then they’d go inside. That was just intriguing. I will leave it to see how it works in the future, how practical it was.

So let’s get down to some good innovation. You know, we saw solar shingles on the Stevens house for the first time. I’ve been waiting for a house to do that, so it was good to see that. We had University of North Carolina in Charlotte; they used geopolymer concrete, so that was a way to reduce the amount of carbon in concrete. University of Kentucky had a safe room, which I really thought was pretty neat. So their house was kind of designed—you know, they’re from the interior of the United States; we’ve had some pretty drastic tornadoes out there, and so disaster relief is high on the minds of a lot of those people. And their house had a safe room, which they made their bathroom, with reinforced walls and doors, a bulletproof window in it, and it’s a place where you can go, on a house that doesn’t have a basement or shelter down below, go into this room and shut the door and be quite safe, so that was kind of intriguing.

Stanford University designed their house with a core center to hold the HVAC system, all the plumbing, the hot water tank, all their controls, which is like a premanufactured core, that then a house could be designed around. And so their concept, being from Silicon Valley, is that you could order this core and go and design a house around it depending on where you are, how large your family is, how many rooms you need, how many stories you need, but yet this core is a standard item, and it would be modular, and it would help reduce the cost and make modular home building easier, cheaper, and have yet flexibility. They also had some really smart controls within their house that let people, when they turned on and off, whether it was lights or appliances, they kind of immediately knew how much energy they were about to use, or going to turn on or turn off, things like that.

Tekla Perry: When I looked at the photos from the competition, I was struck by how gorgeous so many of the houses were. I guess in the past I would think of energy-efficient homes as maybe not quite having so many windows, when you think of the straw bale house and yurts back a ways ago. So, were there a lot of new materials, new technologies, that have come out in the past few years that have made this possible, that have allowed the designs to be more flexible?

Richard King: In the very first competition, you hadn’t even heard of triple-paned window. Now with that technology that gets the R-value up higher, you can put more glazing in your house and still keep it relatively energy-efficient. So, I saw a lot more windows—more than in the past, I think. And again, it’s part of the way the houses are small, and they want to really open up the outdoors to it. And, of course, passive design really lends itself to making a lot of windows in your house, especially on the south side, so we did see a lot of that.

What we also saw was teams using their solar system as shading devices to help—“All right, let’s put more windows here, but we don’t want that glaring sun to come in in the summertime on the south side.” So there were probably four or five of the homes that actually made a separate rack for their solar system, so it actually extended over the back of the house and provided shade—on their back porch, but also for the south-facing windows. So that was kind of a trend. I was impressed too with more open houses and also the quality of the houses.

Tekla Perry: So are you already gearing up for the next competition?

Richard King: Yes, we are. As we speak, the FOA, a funding opportunity announcement, is out on the street to request proposals from teams, because we want to give them two years for the next competition, which will be in 2015.

Tekla Perry: Okay, well, thank you.

Richard King: Hey, you’re welcome.

Tekla Perry: We’ve been speaking with Richard King from the U.S. Department of Energy about the Solar Decathlon, a biennial competition that wrapped up its latest round last month. For IEEE Spectrums “Techwise Conversations,” I’m Tekla Perry.

This interview was recorded 6 November 2013.

Audio engineer: Francesco Ferorelli

Segment producer: Tekla S. Perry

Photo: Jason Flakes/U.S. Department of Energy Solar Decathlon

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