In this time of heightened concern about our environment, 7News is proud to be a part of an exciting breakthrough in television weather radar! Now KMGH-TV has “plugged into the Sun” to power it's weather radar, Chief Meteorologist Mike Nelson and the 24/7 Weather Center Team can look at the sky everyday and forecast, not only the weather, but energy savings and a cleaner environment.

That’s because solar-electric systems that use the renewable energy of the sun to produce electricity – like the 2-kilowatt solar-electric system recently installed by the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) at the 7NEWS weather radar site -- are pollution free and offset the amount of electricity needed from the utility grid.

Solar-electric systems – also called photovoltaic systems or PV – convert the sun’s light directly into electricity. They work anytime the sun is shining. More electricity is produced when sunlight is more intense – high noon, for example – when rays strike the solar cells directly. In Colorado, where Nelson says the sun shines more than 300 days a year, solar-electric systems are highly effective. But even on cloudy Colorado days, a solar system will work at 25% of its capacity or better.

The 7NEWS weather radar solar system was made possible through a partnership between KMGH-TV and NREL to demonstrate the reliability and efficiency of clean solar power. NREL researchers, working on solar energy technologies in Golden, Colorado. for the past 28 years, have made significant progress on development of solar cells that are better, more efficient and cheaper to manufacture.

The Department of Energy invests in solar research to improve America's security, environmental quality, and economic prosperity through public-private partnerships that bring reliable and affordable solar energy technologies to the marketplace, according to its Web site.

“With Mike Nelson’s help, this demonstration project will educate consumers and students about the sun’s power to create the weather and to generate electricity,” said Kerry Masson, director of public affairs for NREL.

An NREL team of Byron Stafford, John Thornton and Bob Hanson designed and installed the 7NEWS weather radar solar system.

The first step was calculating how much power was needed to operate the radar and its support systems. Senior engineer Byron Stafford measured the daily maximum amount of electricity used and came up with 10.4 kilowatt hours a day – a little more than four 100-watt light bulbs would use if they were turned on for 24 hours. (A 100-watt light bulb uses 2.4 kilowatt hours/day.)

A series of eight solar panels was assembled into an 8 ft. X 25 ft. system and mounted on poles next to the radar tower. The system was connected to an inverter, which coverts the electricity from the solar system from direct current (DC) electricity to alternating current (AC). Then it was connected to the Xcel Energy power grid.

During the day, the solar system reliably generates electricity without noise or air pollution. The radar uses the electricity it needs and the rest is sent into the utility grid when energy demand is at its daytime peak. At night, the radar runs on grid power. Through an agreement with Xcel Energy, the TV station is credited for the excess power it generates.

At the end of the year, “this system will probably generate more electricity than it uses,” said Stafford.

“The radar system itself is energy efficient and that was a good place to start our energy calculations,” said NREL principal engineer John Thornton. “As a general rule, it’s more effective to add a solar-electric system after you have reduced your energy consumption as much as possible.”

“For example, if you want to add a solar system to your home, first invest in good insulation, efficient lighting, appliances and windows. That reduces the overall electrical use before you install a solar-electric system,” Thornton said.

More information about solar energy and solar technologies is available from the U.S. Department of Energy and the National Renewable Energy Laboratory website. Consumers interested in exploring how to add solar-electric systems to their homes can get information here.

To learn more about all renewable energy technologies, stop by the NREL Visitors Center located at 10513 Denver West Parkway, Golden, CO. Hours are 9 a.m.-5 p.m. Monday – Friday. Special programs and tour information is available here. The National Renewable Energy Laboratory (NREL) is the U.S. Department of Energy’s primary laboratory for renewable energy and energy efficiency research and development.

(To see how a solar cell works, go to this website.)