The Energy Smart Guide To The 2011 Solar Decathlon

Our guest blogger is A. Siegel, of Get Energy Smart Now. The Solar Decathlon is running on Potomac Park off the National Mall until Oct. 2.

In the fifth Department of Energy Solar Decathlon in Washington, DC, 19 university teams are competing to build the best solar-powered house in 10 categories, each for 100 points, for a total of 1000 points. As with an Olympic Decathlon, the overall winner might actually not win any of the categories but simply be a top performer across all of them. The winning house:

— Is affordable, attractive, and easy to live in — Maintains comfortable and healthy indoor environmental conditions — Supplies energy to household appliances for cooking, cleaning, and entertainment — Provides adequate hot water — Produces as much or more energy than it consumes.

These are the 10 Solar Decathlon 2011 contests: the first five are judged by expert juries: Architecture, Market Appeal, Engineering, Communications, and Affordability. The second five are quantitatively measured: Comfort Zone, Hot Water, Appliances, Home Entertainment, and the all-important Energy Balance.


The most significant competition change from the past is the creating of a cost category which emphasizes affordability.

While cost considerations were part of “marketability” in the past competitions, this was not necessarily a serious element. One team discussed with me in 2009 how they had worked hard to have an audited cost estimate and then discovered that only a few other teams had made similar efforts. Whether correct or not, they were frustrated that, in their perspective, this was not a serious element of the competition analysis. This new category might well have driven the teams into designs that will be marketable at scale.

The 2011 Solar Decathlon Competitors

The Solar Homestead, Appalachian State University

TRTL — Technological Residence, Traditional Living, University of Calgary, Canada

perFORM[D]ance House, Florida International University

Re_home, University of Illinois at Urbana-Champaign

WaterShed, University of Maryland

Self-Reliance, Middlebury College

First Light, Victoria University of Wellington, New Zealand

enCORE, Ohio State University

Empowerhouse, Parsons the New School for Design and Stevens Institute of Technology

INhome, Purdue University

CHIP, The Southern California Institute of Architecture (SCI-ARCH) and California Institute of Technology (CALTECH)

E-Cube, Team Belgium, Ghent University

Y Container, Team China

FLeX House, Team Florida (The University of South Florida, Florida State University, The University of Central Florida, and The University of Florida)

4D Home, Team Massachusetts (Massachusetts College of Art and Design and the University of Massachusetts at Lowell)

Solar Roofpod, Team New York (City College of New York)

ENJOY House, Team New Jersey (State University of New Jersey and the New Jersey Institute of Technology)

Living Light, University of Tennessee

Unit 6 Unplugged, Tidewater Virginia (Old Dominion University and Hampton University)

The Solar Homestead, Appalachian State University

Inspired by traditional Appalachian settlements, the Solar Homestead is a six module building ensemble connected with a Great Porch. Some 8.2 kilowatts (kW) of bifacial solar cells shade the porch. Among unusual elements, the outdoor shower and kitchen speak directly to the concept of meeting ‘new homesteaders’ requirements associated with flexible space appropriate for office, additional bedroom, or otherwise. From my recollection, this is the first Decathlon house to offer a real option for three separate bedrooms and, by the way, two bathrooms (okay, 1.5 plus an outdoor shower). And, on the deck is a sink — think wet bar for entertaining or a second kitchenette for those in the small (120 square feet, including the half-bath) additional room. As part of its market concept, this house could be sold / marketed in pieces: e.g., that 120 foot space with an outdoor shower and mini-kitchenette might fit its own market niche.


My seven-year old wanted to have a picnic at the Solar Homestead and clearly identified with the girl in the video while my son salivated at ‘owning’ the independent ‘FlexUm’ space and wanted to watch a movie on the big screen. As for me, my first impression in a Decathlon opening is that this is an extremely livable space with many attractive features.

TRTL — Technological Residence, Traditional Living, University of Calgary, Canada

Calgary’s TRTL (pronounced “turtle”) stands out with a unique yet, in some ways, very traditional design. Targeted for Treaty 7 Native Peoples in Southern Alberta, it is not hard to see the tipi as the TRTL’s inspiration.

The TRTL’s design seeks to meet not just the ‘technical’ needs of powered living in the cold north (well, the “cold north” compared to the DC area) but also meet the cultural needs of Treaty 7 peoples marrying solar technology with the culture’s identification of the sun as a traditional source of energy and life.

The home has many features derived from traditional life (such as color palettes from traditional art), features local materials, and uses materials very appropriate for remote living (such as magnesium oxide-based structural insulated panels (SIPs) that are highly resistant to fire and mold). These features provide an answer appropriate to the shortfalls in providing Canada’s Native People’s with quality housing in some of the most forbidding areas of the world.


TRTL extends beyond its Treaty 7 partners to address issues faced by many native groups in Canada. Its features include:

— Materials and color palettes that reflect customary art and the natural environment

— Magnesium oxide-based structural insulated panels that are highly resistant to fire and mold

— An 8.3-kW photovoltaic system engineered for high performance in Alberta’s harsh winter climate.

The team claims that their design enables achieving 93 percent of the theoretical performance of its panels. This claim will be interesting to see. The review from both children: “Cool …”

perFORM[D]ance House, Florida International University

As you might understand when you watch the video, my seven-year old has nicknamed Florida International University’s perFORM[D]ance House the “wheelchair house”. Built to withstand hurricane-force winds, perFORM[D]ance house’s louvers can provide shading and privacy along with protection from hurricanes. (As I understand it, these are automatically controlled to deal with the changing environmental conditions — such as the sun’s rotation, etc — which will be interesting to explore with the team.) As with many of the entries, the house’s gardens serve as both a source of nutrition and as part of storm-water runoff control and water bioremediation (grey water).

The design relies heavily on passive design features (such as shading canopies and a white exterior for Florida’s hot sun) and has a weather station to provide data into the automation system to optimize home performance. Both of my children related this house to their aging grandparents, supportive of designing homes that will enable their residents to age gracefully.

Re_home, University of Illinois at Urbana-Champaign

The 2011 University of Illinois at Urbana-Champaign has a real challenge: the 2009 team came in a close second to Germany, really only losing because Germany’s feed-in-tariff system made a huge solar array panel sensible for the German market. On first glance, the UIUC teams looks to have done another magnificent performance with their answer to housing challenges

following a natural disaster: Re_home. The house consists of two modules that can be transported on one trailer for rapid response to disaster situations. The photovoltaic system can be installed flat on the roof prior to shipment. When the house reaches its destination, the panels can be lifted to the optimal angle for sun exposure and used immediately. The house, motivated in part by towns with pocket tornado disasters, is conceived holistically for meeting post-disaster needs. Very straightforward assembly, with the complicated work done in a modular factory, with no piping and ‘plug-and-play’ cross module wiring. Insulating and waterproofing the gaps between the two gaps looks straightforward enough for my ten-year old to handle competently. The Re_Home is a durable and extremely livable space that might be amazing to live in days after losing a home in a storm but which would be great to live in a decade later.

It does the sustainability path due justice. Among other things, the exterior paneling is an unusually sustainable choice (60% rice husks, 22% common salt, and 18% mineral oil) that can handle a multitude of finish options.

WaterShed, University of Maryland

The University of Maryland team is another challenged by a serious Solar Decathlon legacy with the 2007 UMD Leaf House truly a crowd favorite (especially in my household). Like many of the entries, the team is inspired by its region and its region’s particular challenges. In this area, the Chesapeake Bay is truly a centerpiece and one under challenge. Inspired by the Chesapeake Bay ecosystem, the WaterShed proposes solutions to water and energy shortages. Watershed is a clear statement of how a beautiful home can help preserve watersheds everywhere by managing storm water onsite, filtering pollutants from greywater, and minimizing water use.

And, when it comes to ‘thirst’, “the photovoltaic and solar thermal arrays, effectiveness of the building envelope, and efficiency of the mechanical systems make WaterShed less thirsty for fossil fuels than standard homes.”

Both my children thought the floor-to-ceiling window in the shower, overlooking the water reclamation system, was both beautiful and wondered about people looking in. (I’ve since learned that there is a floor to privacy shade option.) As for myself, I am looking forward to see UMD’s liquid desiccant waterfall version 2.0. The DC area is extremely humid and many households (including mine) actually run their air conditioning more as dehumidifier than for cooling. The liquid desiccant system provides a highly energy efficient path for dehumification while adding an attractive feature to the house’s interior. (The 2007 LEAF house had a waterfall desiccant systemwhich was beautiful.) As part of v 2.0’s upgrades, this is designed to work with solar thermal collectors, rather than fossil foolish energy, and thus should be an even more efficient path toward reducing air conditioning demand in humid climates. Hopefully the team will bring v 2.0 to market as my household certainly would think about installing one.

Self-Reliance, Middlebury College

Middlebury College’s Self-Reliance stands out for a number of reasons, in part due to this being a small, liberal-arts college without the ‘technical’ schools that are part of most other teams. In addition, Middlebury academic leadership truly seem to have embraced The Solar Decathlon as part of the curriculum. At many of the large universities, it is uncertain whether the student body is aware that their school is in this international competition. That is not the case with Middleburry (founding site of and academic home of climate activist Bill McKibben). Self-Reliance nudges against the competition’s 1000 square foot limit with its two-bedroom 990-ft2 house designed for a family of four. The exterior, absent panels, would look familiar in a New England landscape with its traditional gable roof. On the interior, its interior landscape has a green wall for growing plants which helps foster a healthier atmosphere. Its design includes stack effect ventilation, which pulls in cooler air toward the ground and vents out warmer air from the skylights.

My children, both, migrated to the concept of ‘owning’ the loft space for their toys and, well, perhaps bed. (Although my son wondered about rolling off even though he sleeps, already, in a loft bed.)

Self-Reliance will be integrated into the Middlebury curriculum with four students per semester to become its residents, expected to conduct community outreach projects related to the mission of the house. They will be encouraged to cook meals made with produce from the green wall and planters and to invite architects, authors, environmentalists, and other speakers to visit.

First Light, Victoria University of Wellington, New Zealand

First Light is called that because New Zealand is the first nation to receive the dawn each day. Inspired by the traditional New Zealand holiday home (the “Kiwi bach”), First Light’s design suggests a relaxed lifestyles with the outdoors and socializing central to living.

First Light’s simple lines and use of natural, low-maintenance materials transform an intriguing design into a beautiful reality. Unique among the houses, First Light’s deck doesn’t only go around the house but through it in a central section that can, if necessary, be closed off from the elements but clearly intended as mainly outdoor living. (Son’s reaction: smart. Daughter’s reaction: ‘can we live in it’.) The house’s insulation is also unique. Remembering that this is the New Zealand competitor, should you be surprised that they used sheep’s wool?When I visit, I hope I have the chance to see their approach to drying clothes in a cupboard that dries clothes by pumping solar-heated hot water through a heat exchanger. On the other hand, my children wish to see the shade covers for the ceiling.

enCORE, Ohio State University

enCORE is aimed a providing cost-effective answers to housing challenges in residential neighborhoods with average income perhaps lower than other urban areas around it. (Modeled on Columbus, Ohio, OSU’s home town.) Tightly designed, this 930-ft2 (86-m2) house provides functionality matching that of much larger homes. Consider, for example, the Murphy bed in the children’s bedroom that enables good floor space for playing in the day with a good size bed for sleeping.

Part of the affordability is, of course, life-cycle affordability achieved through serious energy efficiency — triple-glazed windows, super-insulated exterior, and maximization of natural light.

Empowerhouse, Parsons the New School for Design and Stevens Institute of Technology

Empowerhouse was developed in partnership with Habitat for Humanity of Washington, D.C., and the D.C. Department of Housing and Community Development. It will be moved to a DC community after the competition with the hope that the new residents will become community leaders on how afforadable green practices make sense in every day life.

In terms of design philosophy, here is the team’s description:

Empowerhouse embodies Habitat for Humanity’s vision that all people deserve safe, comfortable, affordable homes.

Empowerhouse certainly delivers on all three recognizing that on affordability, for example, its utility bills will be, roughly, $0 per year.The compact 1,000-ft2 (93-m2) one-bedroom structure showcases the whole-life approach while being sensitive to the existing urban fabric. The shape, building envelope, window placement, and shading were optimized through feedback from energy modeling. In addition, sustainable materials reduce maintenance costs and create a healthy environment.

My children both saw the light loft as a wonderful feature but wondered at building a home for ‘a family’ with only one bedroom.

INhome, Purdue University

INhome aims, clearly, to niche directly into the ‘traditional’

American housing market. Note to the right in the photo: did you notice the garage? That, I believe, is a Decathlon first: providing that space to charge your Chevy Volt with excess power off the roof.

While it would blend in, quite easily, in many Midwest communities, the solar panels aren’t the only design features pointing toward a more sustainable life. Visible elements include a self-watering biowall with vertically arranged plants while ‘hidden’ elements include a reliance on passive design to minimize the energy demands for heating, cooling, and lighting the home. Although the exterior of the INhome could blend in well in a typical Midwestern neighborhood, the house’s design includes many special features, such as:

  • A self-watering biowall with vertically arranged plants
  • Interior finishes that contain pre-consumer or post-consumer recycled content
  • A multi-process air purification system that removes airborne contaminants.

CHIP, The Southern California Institute of Architecture (SCI-ARCH) and California Institute of Technology (CALTECH)

CHIP stands out from its competitors and from traditional American architecture. While only one of two ‘efficiencies’ in the competition, CHIP’s exterior seems something more from Tatooine and its shape could be associated with landing craft from any number of sci-fi movies. Rather than putting insulating inside the structure and then having to drywall on top of it, the SCI-ARCH/CALTECH team chose to cover the outside with insulation. “Wearing its thermal performance “on its sleeve”” has advantages such as the video’s highlighted cost reductions which result from greatly eased installation and the creation of additional interior space where insulation normally would go. While the team sees, considering California cities’ high land prices, CHIP as an affordable dwelling with a small footprint that can be used as infill or placed in zoning that accommodates shared lots, the ease of transport and construction suggest that this could be a quite sensible (with, of course, battery backup) dwelling for remote areas.

E-Cube, Team Belgium, Ghent University

On first glance, as with 2009 Decathlon winner Germany, E-Cube evinced an ‘eh’ reaction. It is, after all, a cube. Yet Team Belgium’s targeted simplicity has won me over to a fan. To foster affordability, ‘do-it-yourself-ability’, and life-cycle flexibility, E-Cube seems is stripped of its nonessential components and finishes, leaving its structure and façade exposed to the interior. Conceived as an affordable building kit (think Sears house without the architectural flourishes) that can be assembled in days rather than months, visiting E-Cube feels like walking in a Meccano-set house.

The basic framing is off-the-shelf materials that are used for warehouses. Every exterior piece (windows, insulated panels, doors) is built to the same dimensions and can be interchanged. And, the Meccano nature extends to the inside: have another child and want another bedroom, it likely would only take hours to put together the pieces to add another room on the second floor (knowing, however, that this would sacrifice vertical space in the living room).

As to affordability, Team Belgium hopes — if nothing else — to win this contest as they have worked, hard, to create a cost-effective dwelling (for purchase, construction, living, and renovation/adaptation).

Y Container, Team China

Y Container uses six recycled shipping containers in a succinct Y-shaped solar house that could support a family or, as shown in the video, two non-spouse young professionals sharing a dwelling. Team China targeted a dwelling easy to transport, assemble, and expand which would provide the freedom to live anywhere with low costs and clean energy.

Everyone in my family loved the partitions and Murphy beds creating two bedrooms in tight spaces while I am intrigued by the automating venting in the roof and want to learn more about their energy systems.As for my daughter, Y Container is top of that seven year-old’s list for a visit at The Solar Decathlon. Considering China’s huge and mounting investments in solar energy, I am interested to see what Y Container features will truly ‘wow’ me.

FLeX House, Team Florida (The University of South Florida, Florida State University, The University of Central Florida, and The University of Florida)

FLeX House is a prototype for a prefabricated home that marries 21st century technology with traditional Florida design. The house, for example, is designed to open up in mild weather for passive cooling while using highly efficient active systems for periods of temperature extremes (hot and cold). This is a ‘hybrid open-and-closed’ building well married with Floridians’ indoor/outdoor lifestyles.

As with many other homes, transportability from centralized production to construction site is part of the design: one truckload can carry the house. And, in line with The Solar Decathlon and the ‘small house’ movement, FLeX House seeks to maximize space efficiency along with energy efficiency to provide affordable, functional, and comfortable living — despite the small total footprint.

FLeX House, with a 5 kW system, has one of the smaller arrays in the Decathlon suggesting a truer focus on affordability and using efficiency to minimize total electricity requirements. (Though, we should recognize the different regions … a Florida house requires fewer panels for the same output compared to a Canadian home.). And, with humidity challenges like or worse than the Maryland area, the FLeX House has a liquid desiccant system for dehumidification to reduce overall air conditioning loads that I will be interested to see.

4D Home, Team Massachusetts (Massachusetts College of Art and Design and the University of Massachusetts at Lowell)

The New England-inspired 4D Home inspired an ‘isn’t that an attractive house’ reaction which is a wonderful thing to have for breaking into traditional housing markets. (And, while I have yet to visit, that ‘isn’t that attractive’ (actually, ‘beautiful’) is the reaction in person and on the web.) As with all entries, 4D is extremely efficient, seeking to minimize active renewable energy requirements. Much of this, such as having the solar panels provide shade against summer sun, is essentially invisible to the average American — even as it so directly visible.

The house, designed with two bedrooms, can be easily reconfigured with sliding partition walls.

Solar Roofpod, Team New York (City College of New York)

Solar Roofpod responds to the fact that urban rooftops are largely under-used. Intended for existing mid-rise buildings, this concept puts a new dwelling on the roof: one that provides its own power and reduces rainwater runoff due to its gardens.The Solar Roofpod would be built in modules while providing purchases the ability to customize their ‘roofpod’ to their needs (number of bedrooms, solar orientation, otherwise …)To be fair to all, it is time to take a moment for honesty. This is one of my favorite entrants. Not because I want to live in the Solar Roofpod but because I see this as having one of the most straightforward paths to market while helping assist sustainable living for a family while addressing larger sustainable issues.

  • This has an immediate market if a major city (read New York) would not include structures like this in density calculations. (Have an existing apartment building, here is a path to add additional units without having zoning hearings …) Perhaps do this based on distance to the nearest subway station. Thus, rather than zoning questions about density, the only questions would be technical: can the roof handle it. (Informal discussions with the appropriate staff suggests to the team that would mean about 25–50% of New York City’s multi-family residences (with a flat roof) could handle these.) And, if this occurs, perhaps Mayor Bloomberg could spark a Selling New York competition for realtors seeking to sell these prime new penthouse units.
  • Simple fact: urban living is more sustainably, globally, than suburban living. This puts small-footprint housing in the middle of small-footprint living rather than fostering a ‘sustainable’ vision that relies on a couple gallons of gas car ride to get there from work.

ENJOY House, Team New Jersey (State University of New Jersey and the New Jersey Institute of Technology)

ENJOY House stands out from the competition with its concrete construction which shows that architecture is an art: it is in the eye of the beholder. My daughter is not enthused about the look while my son sees it as a ‘cool’ statement and is enamored with the floating roof. Both however, as with Team Florida, resonated with the design’s clear functionality with their aging grandparents in mind. The unusual roof design optimizes rainwater collection and the concrete construction creates a fast (and cost-effective) on-site construction (with pre-caste pieces trucked to the site). As for myself, I am intrigued by this house and will reserve judgment until I’ve had the chance to visit and speak with the team.

Living Light, University of Tennessee

Living Light is a very high-quality efficiency house whose form is inspired by the cantilever barns of southern Appalachia. In terms of actual living space, this is one of the smallest (if not smallest homes) because of the team’s intent: they will take Living Light on a tour throughout Tennessee, showing the reality of the promise of solar technology. Thus, this is designed to be easily transported (with the direct living space transported on one truck and additional transport for elements like decks and spare solar tubes. Along with more solar electricity capacity than likely required, this design element helped push up the unit’s price.

This design has many notable features. In terms of interior design space, my family loves the quality of finish and both of my children, on seeing the video’s discussion of how the kitchen and other elements can be masked, separately exclaimed “Mom would love that.”

In terms of technology, Living Light stands out for

  • Its North-South walls which are a dynamic double façade system made of alternating translucent and transparent panes and horizontal blinds. These work automatically with an energy recovery system to cool in summer and heat in the summer with great efficiency.
  • Use of Solyndra solar electricity tubes that capture sunlight across a 360° surface and convert it to electricity. (Thus, amid the Solyndra ‘scandal’, this serves as a very tangible reminder that the Solyndra product, on the most fundamental level, worked … even as market developments priced them out of business.)

Unit 6 Unplugged, Tidewater Virginia (Old Dominion University and Hampton University)

Unit 6 Unplugged is another home designed to meet local city housing needs. Architecturally based on the arts and crafts-style homes found throughout the center-city neighborhoods of Norfolk, Virginia, the house is set apart due to its solar power and more including its nearly floor-to-ceiling windows in the central living space. As for windows, Unit 6’s porch look to be truly appealing with motorized windows that allow it to be either an open porch or an enclosed sunroom enabling it to be a year-round part of living. (Both kids, by the way, found this to be fascinating and appealing.) In terms of technology, Unit 6 features something that most homes and businesses should have: window and door sensors that provide security system information and prevent the HVAC system from operating when either is open.

For Additional Videos see the great Solar Decathlon material at Planet Forward.