Solar Decathlon Review, day 3: Our Favorites
by Matthew Bushey, September 30, 2011
This Sunday, October 2nd is the final day for public viewing of the 19 student-built solar-powered homes of the Solar Decathlon on the National Mall. The excitement is building as the points are adding up and a winner is coming into focus. Tomorrow, Saturday Oct 1st, the winner will be announced, the team that has accrued the most points across the 10 categories in fields such as architecture, engineering, energy and affordability.
Many of the houses incorporate some of the technologies and green design strategies that I described in yesterday’s post
, but the best houses are the ones that bring it all together beautifully. Here are 3 of our favorites:
LIVING LIGHT by the University of Tennessee
This house is based on the cantilever barns of Southern Appalachia, with an open plan anchored by a dense core at each end. But the real intelligence is in the envelope.
The all-glass north and south elevations consist of a 16” thick double-façade system, with a fixed plane of glass on the exterior, alternating fixed glass and full-height casement windows on the interior, and internal blinds. In the winter, the air space within the south-facing façade collects heat that is directed to an ERV, supplying the home with preheated air. In the summer months, the system works in reverse, drawing fresh air from the north façade by the ERV and pre-cooling it before it hits the ductless mini-split units. Exhaust air is directed through the south façade to cool the cavity and reduce heat gain.
Energy is generated from a 10.9 kW rooftop array of cylindrical PV panels. Look closely: those are cylindrical tubes that make up the canopy over the south façade. Thin-film PVs are wrapped around these tubes, collecting sunlight from any angle. There is no need to worry about the correct angle of the panels here, since the cylinders absorb sunlight from all directions.
You can get more info on the University of Tennessee solar house from the project website, livinglightutk.com
, including some great detailed descriptions and explanations of the smart façade, roof top array, and more, at: livinglightutk.com/smartsystems/
WATERSHED by the University of Maryland
This house is all about the conservation and management of our water resources. Coming from the Chesapeake Bay area, the students of the University of Maryland drew inspiration from the 64,000 square mile Chesapeake Bay watershed and have designed a house that addresses the storm water issues that threaten this fragile ecosystem.
The form of the house is defined by two rectangular modules with a split-butterfly roof. A 9.2 kW solar PV array covers one side, and a green roof tops the other. Rainwater is captured from the roof and directed to a series of captured wetlands, where the water is naturally filtered by plants until it can be pumped out for reuse as irrigation water. Greywater from the shower is also directed to the constructed wetlands for reuse.
Finishes include thermo-treated exterior wood siding of poplar and ash, and recycled concrete countertops.
This is the 4thtime the University of Maryland has competed in the Solar Decathlon, and their experience is paying off: as of this writing, they are currently in 1stplace.
More information on WaterShed can be found at the University of Maryland project website, 2011.solarteam.org
SELF RELIANCE by Middlebury College
This is the first year that a Vermont school is competing in the Solar Decathlon, and as a Vermont architect, I’m happy to say that Middlebury College has put up an impressive first showing.
The Middlebury house, dubbed Self Reliance, is a modern take on the traditional Vermont farmhouse. It hits so many of the themes we all associate with the Vermont lifestyle: natural materials, sustainable food production, and family-friendly spaces.
Wood floors were harvested from Sugar Maple trees on the Middlebury campus. The kitchen floor and island countertop is made of local Vermont slate. And the children’s bedroom furniture is made by our friend Lincoln Brown of Modern Vermont.
While most of the other houses on the Mall covered every possible surface with spray foam insulation, Middlebury came out firmly against the stuff and instead went with a completely cellulose-insulated envelope. They explained their approach this way: “Conventional insulations such as fiberglass or spray-in foam contain particles hazardous to all forms of life. They are also non-biodegradable and require tremendous amounts of oil and energy to process. On the other hand … Cellulose insulation is safe, low-energy, cheap, and – most importantly – natural.”
Self Reliance is focused on personal, sustainable food production. A greenhouse wall in the kitchen is not much more than a system of shelves for growing potted vegetables and herbs, but it is centrally located and promotes home-grown healthy eating. By making this such a prominent feature of the house, the students are trying to highlight the connection between local food production and energy use.
This is a very family-friendly house, designed for a family of four, with a division of public and private spaces. Most of the other schools seem to struggle with the space constraints of the competition, designing homes under 1,000 square feet with murphy beds, movable walls, and multi-purpose spaces. Many don’t even have real bedrooms. The Middlebury house actually has TWO bedrooms, and a play loft accessible by a metal ladder.
Middlebury is doing very well for this being their first time in the Solar Decathlon. They scored 4th in the prominent Architecture category, and came in 1st place for “Home Entertainment”. This is one of those categories that aims to show that these are real, livable homes, so the students had to throw a movie night and 2 dinner parties. They probably won due to the delicious localvore meal they prepared, which their guests praised as being very “Vermonty”.
On Wednesday, Metropolis Magazine called Self-Reliance one of “the two most striking projects at the Decathlon”. They described it as “a warm and straightforward modern version of a traditional New England home that beautifully uses native Vermont materials.”
Congratulations to the Middlebury team and to all the teams at the Solar Decathlon, and good luck tomorrow as the grand prize winner is announced!