How do you identify the measured contest captain on each U.S. Department of Energy Solar Decathlon team? Listen for words such as datalogger, monitored performance subcontest, and database-driven scoring application.

These students focus on maximizing the points their teams earn in the five measured contests:

• Comfort Zone
• Hot Water
• Appliances
• Home Entertainment
• Energy Balance.

To be successful in measured contests, the decathletes must strategize. For some measured contests, they must complete tasks such as washing a load of towels and operating a home entertainment system for a set time. A group of observers keeps detailed logs on their task performance that are later translated into scores. For other measured contests, the competition houses are equipped with sensors that measure factors such as humidity and temperature. An instrument called a datalogger keeps track of the data points and sends this information to a central database every 15 minutes.

The datalogger in Team New Zealand’s house is competition-ready. (Credit: Alexis Powers/U.S. Department of Energy Solar Decathlon)

“The equations in the rules define how we take information from the dataloggers and observer logs and calculate a score,” says Mike Wassmer, the scorekeeper and assistant competition manager of Solar Decathlon 2011. These algorithms translate a sea of data into a final score for each measured contest.

To follow your favorite team’s progress in the measured contests, visit the scoring pages on the Solar Decathlon website. Then tell all friends about it—and make sure to spice up your conversation with words such as observer logs and central scoring database.

Alexis Powers is a member of the Solar Decathlon communications team.

One of the 10 contests in the U.S. Department of Energy Solar Decathlon 2011, Energy Balance measures the net energy each house produces or consumes over the course of the competition. 

The Energy Balance Contest simulates how most residential solar electric systems work today. Each team house is equipped with a bidirectional utility meter that enables power flow to and from the electric utility. When the sun shines, the house’s solar electric system produces electricity. If the system produces more electricity than the house needs, the excess electricity flows backward through the meter to the grid.  At night, when the solar electric system is not producing electricity and the refrigerator is running, for example, the house consumes electricity from the grid, and the meter runs forward. To achieve a zero meter reading at the end of the competition, the solar electric system has to produce as much energy as the house consumed.

These photos of the Team Tidewater Virginia smart meter, taken on opening day, indicate the team had generated 5 kW hours of electricity in the first hours following the start of the competition. (Photo from Lachlan Fletcher, Studio 18a)

“In 2011, we changed the rules to reduce the incentive for producing a surplus amount of energy,” said Richard King, Solar Decathlon director.  “Instead of awarding bonus points for excess electricity generation, like we did in the 2009 competition, we are rewarding teams for producing only what they need.”

Having a rainy day like today changes the dynamics of the teams’ strategies. All the teams have planned on one or two days of cloudy weather out of the 10-day competition. When a cloudy day comes on the first day, it becomes very strategic to try to predict how many other cloudy days loom ahead.

“A key to success will be having a good weatherperson on the team,” Richard said. “If a team feels confident that the weather will become sunny, it’s easier to strategize whether to conserve energy or operate the house normally.”

If you want to see the teams’ strategies, watch the Hot Water, Appliances, Home Electronics, and Comfort Zone contests to see if the students are holding back on expending energy.

Carol Anna is the communications manager of the U.S. Department of Energy Solar Decathlon.