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Email19th Overall
October 26, 2007
Cornell returned in 2007 having had one previous Decathlon under its belt. In 2005, it placed second overall.
The team at Cornell came up with the concept of the "Light Canopy" for this year's competition. Knowing that not everyone who wants a solar house can afford one, the team took an add-on approach. Its canopy is a steel frame made of off-the-shelf steel that can be customized to fit over any house, regardless of its current roof shape or orientation to the sun. Most houses on the National Mall cost well over $250,000 to build, but the Cornell house could be mass-produced for around $16,000 dollars -- with the biggest expense being the panels themselves.
"We hope that our strategy can be employed in places like developing nations or disaster zones ... areas where the grid doesn't exist or has been destroyed," said Bryan Wolin, a senior science communications major. The canopy itself would take only one day to install over a pre-existing building. The short installation time makes it a viable solution for the areas that are off the grid.
The canopy had 69 solar panels, each 110W, made by GE-- for a total of 7.59 kW. Wolin said that the whole system is rated at 11 percent efficiency, but the actual is closer to 8 percent. The panels were coupled with Concorde Battery Corporation PVX-9150T lead-acid batteries. The energy generated was controlled by OutBack Power Systems FLEXware system components.
Also on the canopy were evacuated tubes, by Sunda Seido, that were large enough to heat two hot-water tanks. One of these tanks was used for domestic hot water and the other was used to run hot water through coils in the duct system. These coils served as the heating system for the house.
In New York State, the minimum R-value for a home is R-25. By using SIPs, with an R-value of 40, the team was able to decrease energy usage by 75 percent.
Cornell's' house already has been bought for $150,000 and will be permanently installed in Connecticut as a guest home.