The University of Nevada Builds DesertSol
Based in the desert, a place with abundant sunshine, the University of Nevada, Las Vegas, designed a home to harness the sun for energy, as well as capture rain for irrigation and cooling.
The team finished in 2nd place overall, only 3.5 points away from first place, which went to Vienna University of Technology in a very close Solar Decathlon competition. The team scored a few other event victories, receiving 1st place in Market Appeal and Energy Balance, 2nd place in Communications, and 3rd place in Engineering. The house produced more solar electricity than it used or needed. The overall cost of the house with the energy system and all the appliances was $298,600.
The Solar Decathlon truly tests a home’s performance. In order to receive a score in the Entertainment event, each team must host a dinner party and screen a film. This tests the home’s general electrical systems and the combined efficiency of the appliances. They aren’t sitting around saving electricity and using candles. They’re watching films on large screen TVs, baking chocolate cakes, making multi-course meals and leaving the lights on. It’s all powered by the sun. Here are UNLV’s Dinner Menus and Recipes. (32 page pdf with delectable looking pictures. There’s a good recipe for chocolate cake and braised beef flank steak stew.)
Since water transfers heat about 20 times more efficiently than air, the home used solar hot water, radiant floor heating. In addition, 30 photovoltaic panels, each with its own micro-invterter, lined the top of the home to supply it with electricity.
I took the opportunity to see the spacious-feeling 754 square foot home while it was open to the public.
- A weathered wood rain screen shades the building’s structure.
- Digitally fabricated retractable solar shade screens shield the hottest sides of the house in the summer and provide direct sun for warmth in the winter.
- A water feature captures water from the occasional desert downpour and uses it for irrigation and spot cooling on the outside deck with a cool tower, which uses less water than conventional misters.
- Folding doors open completely, allowing indoor activities to spill onto the outdoor deck space and doubling the square footage for entertaining.
- A home automation system ensures the house operates at peak efficiency and allows the lights, appliances, and thermostats to be controlled from an easy-to-use interface on a mobile device.
- Photovoltaic panels provide electricity and shade the outdoor living space.
- Solar thermal collectors provide radiant floor and water heating.
- Advanced structural design framing clad in reclaimed pre-weathered materials saves lumber and provides more insulation to the living spaces.
- A fire-protection sprinkler system combined with a potable water plumbing system ensures that fresh water is available each time a cold-water fixture is used and results in a non-stagnant sprinkler system.
- Layers of closed-cell, open-cell, and continuous rigid insulation ensure that the house is air-tight and highly heat-resistant and prevents thermal bridging.
Final Overall Scores
All of the teams learned a lot in the Solar Decathlon to design, build, finish, dismantle, transport, rebuild, compete in the competition and display the homes (with a smile, over and over and over again) to help educate the public.
They all had amazing, sometimes arduous, yet highly educational and rewarding experiences. The final score is a summation of task completion, monitored performance of the homes and jury evaluations within 10 events.
Features and technologies sections from solardecathlon.gov.
Visit the team’s website: solardecathlon.unlv.edu