U.S. Department of Energy's Solar Decathlon | Powered by the Sun

Solar Decathlon 2013

Solar Decathlon Village Energy Balance

The U.S. Department of Energy Solar Decathlon 2013 used a small power grid, or microgrid, to distribute energy safely and reliably among the competition houses and to the utility grid.

Graphs of the energy produced by Solar Decathlon 2015 team houses. Cumulatively, the houses produced 6,208 kWh of electricity and consumed 4,159 kWh, for a net energy production of 2,049 kWh. This is an equivalent carbon offset of planting 112 trees or avoiding 3,684 miles driven in an automobile.

When the sun was shining, the solar electric panels on the houses produced energy that was used to power appliances, lights, mechanical systems, and electronics. Excess energy flowed from the houses, through the microgrid, and to the Orange County community when more energy was generated than consumed.

If there was little or no sunshine, the utility could deliver energy to the Solar Decathlon village without an interruption in service. This allowed the houses to continue functioning at night, when skies were cloudy, or when the demand for energy exceeded the energy produced by the houses.

How much energy did the houses produce?

The display above shows the relation between energy produced and available sunshine.

  • Energy Produced by the Houses — The blue bars in the graph show how much energy (in kilowatt-hours) was converted from sunlight into electricity by solar panels on the team houses.

  • Solar Radiation — The curved orange lines in the graph indicate the sunshine available (in watts per square meter) in Irvine for conversion into electricity by the team houses.

  • Weather Forecast — The local weather affects how much energy the houses produce. If it is sunny, the houses have access to lots of sunshine to convert to solar energy. When the sky is cloudy, the houses have less sunlight to convert, so they generate less electricity.

Did the houses generate more energy than they used?

To find out, look at the graphics above.

  • Cumulative Energy Production — This section shows the total energy produced by the houses and the energy the houses consumed for daily operation. Net energy is determined by subtracting consumption from production. If the value for net energy is a positive number, the houses produced more energy than they used during the competition.

  • Equivalent Carbon Offset — Solar Decathlon houses use clean, renewable energy from the sun instead of carbon dioxide-emitting sources such as fossil fuels.

    • Number of Trees Planted — Because trees remove carbon dioxide from the atmosphere during photosynthesis, the carbon impact of the houses is similar to planting the numbers of trees shown.

    • Vehicle Miles Offset — Clean energy produced by the Solar Decathlon houses has offset the equivalent amount of carbon dioxide generated by driving a vehicle in California this many miles.