Skip Navigation to Main Content
Photo of Solar Decathlon Director Richard King being interviewed by a videographer.

Solar Decathlon Blog - Contests

Below you will find Solar Decathlon news from the Contests archive, sorted by date.

Technology Spotlight: Energy-Recovery Ventilation Systems

Monday, August 18, 2014

By Alexis Powers and Carol Laurie

Editor’s Note: This post is one of a series of technology spotlights that introduces common technologies used in U.S. Department of Energy Solar Decathlon team houses.

Good ventilation is vital for maintaining healthy indoor air quality. Houses built to modern energy efficiency standards, such as U.S. Department of Energy Solar Decathlon competition houses, are tightly constructed to allow very little outside air to leak in. As a result, odors, chemicals, particles, and humidity can become trapped, increasing indoor air pollution.

Energy-recovery ventilation systems provide tightly constructed houses with fresh air while minimizing energy loss. These systems rely on heat exchangers to efficiently transfer heat between indoor and outdoor air supplies. There are two types of energy-recovery ventilation systems: heat-recovery ventilators (HRVs) and energy-recovery (or enthalpy-recovery) ventilators (ERVs). An HRV uses fans to pull fresh air into a house while simultaneously exhausting stale air. In the winter, the heat exchanger transfers heat energy from the warmer outgoing air to the cooler incoming air to reduce the need for heating. In the summer, the system reduces the need to cool incoming fresh air by sending the cooler exhaust air past the warm intake stream. An ERV goes one step further by controlling indoor humidity as well as temperature. An ERV transfers water vapor along with heat energy to keep the interior humidity constant.

These ventilation systems can recover 70%–80% of the energy from a house’s outgoing air supply to help maintain a comfortable indoor environment.

Photo of a box-shaped energy recovery ventilator inside a mechanical closet.

Team Ontario used this energy recovery ventilator in its “ECHO” house. Energy recovery ventilation systems help maintain a comfortable indoor environment by recovering 70%–80% of the energy from the outgoing air supply. Credit: Carol Laurie, U.S. Department of Energy Solar Decathlon

Several Solar Decathlon 2013 teams incorporated energy recovery ventilation technologies into their competition houses. Norwich University provided continuous ventilation of its “Delta T-90” house by using a multiunit HRV system that was 92% efficient, ductless, and whisper-quiet. Team Ontario (Queen’s University, Carleton University, and Algonquin College), which received first place in the Solar Decathlon 2013 Engineering Contest, used an ERV in its “ECHO” house to dramatically reduce the energy needed to condition indoor air.

Photo of the exterior of a modern house.

Norwich University used a multiunit HRV system that provided continuous ventilation in its Solar Decathlon 2013 “Delta T-90” house. Credit: Jason Flakes/U.S. Department of Energy Solar Decathlon

Visit the Energy Savers website to learn more about energy-efficient ventilation systems.

Alexis Powers and Carol Laurie are members of the U.S. Department of Energy Solar Decathlon communications team.

 

 

 

What Makes a House a Home?

Thursday, August 14, 2014

By Carol Laurie

A house is just a building until people live in it. Then it becomes a home.

Although U.S. Department of Energy Solar Decathlon houses are not lived in during competition, Solar Decathlon visitors may ask themselves whether they could be comfortable homes when stepping through their thresholds.

Could I live here?

From a competition standpoint, this question is answered through the Home Life Contest, which measures how well each house accommodates comfortable living—including aspects such as sharing meals with friends and family, watching movies, and using a computer. The Home Life Contest also simulates taking a warm shower and spending time in a well-lighted space.

Photo of a man wearing a chef’s hat cooking at a stove, with people sitting at a table in the background.

Decathletes from the University of Nevada at Las Vegas host a meal for student dinner party guests during the U.S. Department of Energy Solar Decathlon 2013. Dinner parties are part of the Home Life Contest, which helps teams get to know one another while demonstrating how comfortable the competition houses might be to live in. Credit: Eric Grigorian/U.S. Department of Energy Solar Decathlon

For this contest, teams receive points for:

  • Hosting two dinner parties for neighboring teams
  • Hosting a movie night for neighboring teams
  • Turning on all interior and exterior house lights during specified time periods
  • Operating a television and computer during specified time periods
  • Producing 15 gallons (56.8 L) of hot water (110°F/43.3°C) from the shower in 10 minutes or less several times during the competition.

Teams plan their dinner party menus in advance, and each menu must feature food and beverages prepared in the house. (See the 2013 University of Las Vegas team’s menu for an example.) For the movie night, guests from neighboring teams watch a movie with the host team on its home theater system. Together, the dinner parties and movie night evaluate the functionality of each house while simultaneously providing an opportunity for competing students to get to know one another.

Completing these tasks brings teams together and provides an indication of whether each Solar Decathlon house could be considered a home.

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

 

 

 

Balance of Power: Solar Decathlon Contest Requires Energy Efficiency and Power Production

Thursday, July 17, 2014

By Carol Laurie

Not consuming energy is better than buying or producing it—even when that energy is generated by clean, renewable solar. That’s the message the U.S. Department of Energy Solar Decathlon 2015 is sending to decathletes through the Energy Balance Contest, which measures the energy each team house produces and consumes over the course of the competition.

The contest is divided into two subcontests: energy production and energy consumption. To earn full points in the energy production subcontest, teams must produce at least as much energy as they consume, achieving a net electrical energy balance of at least 0 kWh. Reduced points are earned for a net electrical energy balance between -50 kWh and 0 kWh. For the energy consumption subcontest, teams must limit their electrical energy consumption to 175 kWh over the course of the contest. This consumption level is significantly less than that of a comparably sized, newly constructed, code-compliant U.S. house.

Photo of a young man wearing an oven mitt and holding a pan of food above a stove.

Michael Kinard, a member of the University of North Carolina at Charlotte Solar Decathlon 2013 team, prepares traditional southern cuisine for dinner guests from other university teams. To achieve high scores in the Solar Decathlon 2015 Energy Balance Contest, teams will have to use energy strategically when completing competition tasks such as cooking and hosting dinner parties. Credit: Eric Grigorian/U.S. Department of Energy Solar Decathlon

“Teams will have to think carefully about energy use to score well in the Energy Balance Contest,” said Joe Simon, U.S. Department of Energy Solar Decathlon competition manager. “They will have to design houses that are extremely energy-efficient and will have to operate them intelligently.”

According to Simon, the Energy Balance Contest will require teams to complete all competition tasks—such as doing laundry, running the dishwasher, and hosting dinner parties—using approximately 60% of the energy consumed by the average house built today.

“Challenges presented by the Solar Decathlon through contests like Energy Balance require teams to establish strategic and sometimes creative strategies to win,” he said. “By encouraging innovation like this, the Solar Decathlon provides students with a unique and effective way of learning science, technology, engineering, and mathematics that prepares them for careers in clean energy.”

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

Solar Decathlon Village Powered by Microgrid and Sponsor Support

Wednesday, June 25, 2014

By Carol Laurie

Since the U.S. Department of Energy Solar Decathlon 2009, a temporary, ground-laid electrical grid (or “microgrid”) has connected Solar Decathlon houses with one another and the local utility. The village microgrid allows excess power generated by the houses’ solar electric systems to be sent back to the larger city utility grid and its customers. The microgrid also enables the competition houses to draw energy from the utility when consumption exceeds production.

In Solar Decathlon 2002, 2005, and 2007, Solar Decathlon houses were grid-independent and ran off batteries that stored the electricity generated by their solar photovoltaic systems. In 2009, competition organizers decided to connect the houses to the electrical grid to better reflect the typical residential configuration found today. By connecting each house to the local electric utility grid, the microgrid enables houses in the Solar Decathlon village to function the same way solar households throughout the United States operate.

 

Photo of a group of people talking next to an electrical box.

Byron Stafford (second from left), who served as the Solar Decathlon site operations manager from 2002 until 2013, consults with a team member from the City College of New York (right) about interconnecting the team’s house with the 2011 village microgrid. Stafford and his team of engineers transitioned the solar village from battery storage to grid power by installing the first Solar Decathlon village microgrid in 2009. (Credit: Carol Anna/U.S. Department of Energy Solar Decathlon)

Energy Balance Contest

The microgrid also changed the Energy Balance Contest, for which teams earn points based on their energy production and energy consumption. Before the microgrid, organizers measured the flow of energy in and out of battery storage during the competition. Now, the energy each house produces and consumes over the course of the competition is measured with a bidirectional utility meter.

When the sun shines, the solar system produces electricity that is used to power appliances, lights, mechanical systems, and even an electric car. If the system produces more electricity than the house needs, excess electricity flows from the house back into the microgrid and the larger utility grid. At night, or when the demand for energy exceeds the amount of energy being produced, the house consumes electricity from the grid.

In this way, the microgrid provides two-way power flow and enables the Solar Decathlon village to operate continuously regardless of available sunlight or household electricity requirements.

Powered by Sponsors

The Solar Decathlon depends on sponsors to provide the supplemental expertise and equipment needed to design, build, and operate the village microgrid.

For the 2009, 2011, and 2013 competitions, Solar Decathlon sponsor Schneider Electric provided microgrid design and engineering services as well as electrical distribution equipment required to safely and reliably connect the Solar Decathlon village to the local utility. In 2011 and 2013, Schneider Electric also provided a proprietary metering and data system that enabled online and onsite demonstrations of real-time electricity generation and consumption in the village.

The microgrid also depends on local utilities to enable interconnection of the main utility grid with the Solar Decathlon microgrid. Edison International (the parent company of Southern California Edison) provided this crucial sponsorship in 2013, and Pepco stepped up to the plate for Washington, D.C., events in 2009 and 2011.

Other microgrid sponsors include MicroPlanet, which sponsored voltage regulation equipment in 2013, and M.C. Dean, which installed the microgrid in 2011.

All of these sponsors worked together to provide a valuable addition to the competition.

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

Vienna University of Technology Wins Solar Decathlon 2013!

Saturday, October 12, 2013

By Solar Decathlon

Team Austria from the Vienna University of Technology has won the U.S. Department of Energy Solar Decathlon 2013.

Photo of the exterior of LISI.

Team Austria’s LISI house is the winner of the U.S. Department of Energy Solar Decathlon 2013. (Credit: Jason Flakes/U.S. Department of Energy Solar Decathlon)

The first-time U.S. competitor consistently wowed juries with its LISI house, after winning first place in the Communications Contest, second place in Market Appeal, and tying for third place in Engineering.  In measured contests, Team Austria received first place in both the Hot Water and Energy Balance contests.

University of Las Vegas Nevada took second place in the overall competition, and Czech Technical University received third place.

The winner of the Solar Decathlon is the team that best blends affordability, consumer appeal, and design excellence with optimal energy production and maximum efficiency.

Results for the final juried contest, Engineering, were announced today prior to the overall competition winners. Team Ontario (Queen’s University, Carleton University, and Algonquin College) placed first.

Photo of the Team Ontario house.

The Engineering Contest first-place winner is Team Ontario (Queen’s University, Carleton University, and Algonquin College). (Credit: Jason Flakes/U.S. Department of Energy Solar Decathlon)

“Team Ontario revealed a complete understanding of building science, a very good building envelope for the target climate, and excellent integration of passive and active strategies,” said Engineering Contest juror Kent W. Peterson of P2S Engineering. “We believe this team best demonstrated design excellence with optimal energy production and maximum efficiency.”

Second place in Engineering went to Czech Technical University from the Czech Republic. Three teams shared third place: Team Austria from Vienna University of Technology, The University of North Carolina at Charlotte, and University of Nevada Las Vegas

The Engineering Contest jurors evaluate each house’s energy-efficiency savings, creative design innovations, and the functionality and reliability of each system.

See the Solar Decathlon website for final scoring results.