National Renewable Energy Laboratory (NREL) - Innovation for Our Energy Future
News Release

New Design Tool Analyzes Cost of Operating a Building Over its Lifetime


Golden, Colo., August 2, 2002

Imagine being able to estimate the energy life-cycle costs of a new building by simply entering numbers into a software program. Thanks to the new Energy-10 design tool, this is now possible.

The new software - Energy-10 Version 1.5 - is an upgrade to the original program developed at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL).

The new Energy-10 contains seven upgrades including a discounted cash-flow evaluation of a building over its lifetime and a more powerful graphing package. The cash-flow evaluation of a building is determined and discounted to the present value taking into consideration such factors as the initial cost of construction, mortgage payments, annual electric costs and annual tax benefits. Costs can be estimated using simple scaling laws or users can supply their own cost estimates.

"Energy-10 allows the user to play 'what if' games while designing a building or home," said Energy-10 author Doug Balcomb, research fellow at NREL. "What if I change the windows? What if I add in energy efficient equipment? What if I let the daylight in and turn down the lights?"

Helping architects and engineers understand the energy implications of their work is critical in any strategy to reduce greenhouse gas emissions and global warming. The life-cycle cost feature helps the designer make the case for incorporating energy efficiency features by evaluating their cost effectiveness, which is usually very positive.

Energy-10 now has 2,061 registered users and has been licensed to 60 colleges and universities where it is being used as a teaching tool for architects and engineers.

Energy-10 allows an architect to watch a detailed simulation of how his building will use energy and shows ways to reduce energy consumption. The software simulates a year of hour-by-hour operations, a process that requires about one billion calculations in a few seconds and displays annual, monthly or hour-by-hour energy performance graphs.

The software incorporates detailed historical weather data for 239 locations around the country, expandable to 3,945 locations, enabling architects to accurately match their building with a site's weather patterns.

Energy-10 Version 1.5 is the result of collaboration among NREL, Lawrence Berkeley National Laboratory and the Berkeley Solar Group. It is being distributed by the Sustainable Buildings Industry Council (SBIC) in Washington, D.C., which also provides training workshops and user support. SBIC can be reached at 202-628-7400, ext. 210.

For more information, please contact NREL Public Affairs at (303) 275-4090 or email public.affairs@nrel.gov

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