This is an excerpt from EERE Network News, a weekly electronic newsletter.

August 07, 2002

NREL Updates Design Software for Energy Efficient Buildings

DOE's National Renewable Energy Laboratory (NREL) released an update of its popular Energy-10 software last week. The design program allows architects to watch detailed simulations of how their building will use energy and shows ways to reduce energy consumption. The software simulates a year of hour-by-hour operations and displays annual, monthly, or hour-by-hour energy performance graphs. It also helps analyze the contributions of approaches such as daylighting, passive solar heating, and natural ventilation.

The new Energy-10 Version 1.5 contains seven upgrades, including a discounted cash-flow evaluation of a building over its lifetime and a more powerful graphing package. NREL collaborated with DOE's Lawrence Berkeley National Laboratory and the Berkeley Solar Group to produce the update. See the NREL press release.

The Sustainable Buildings Industry Council (SBIC) distributes the Energy-10 software. See the SBIC Web site.

If the newest data from the 2000 U.S. census can be trusted, the United States needs more architects to use Energy-10. According to the census figures, only 47,069 U.S. homes were heated with solar energy in 2000, down from 54,536 homes in 1990. It's unclear, however, if people using passive solar energy may consider their homes to use no fuel for heating. In 1990, the census lists 543,907 homes that used no heating fuel; that rose to 731,506 in 2000. The census also appears to allow only one answer, which might prompt solar home residents to claim their backup heating source. See the 2000 census results on the U.S. Census Bureau Web site (PDF 40 KB). Download Acrobat Reader.

More data and comparisons to 1990 are available on the Census Bureau Web site under Demographic Profiles and in the American FactFinder section.