Feature Article

Getting to Zero: The Frontier of Low-Energy Buildings

Despite the buzz about zero-energy buildings, just what zero-energy means and how to achieve it remain confusing at best. This article sorts out the confusion and sheds light on some of the stumbling blocks along the path to zero-energy.

The home of Otto Van Geet, senior mechanical engineer in the Site Operations group at NREL, is located at 9,200 ft (2,800 m) in Clear Creek County, Colorado, and is not connected to the utility grid. A highly efficient building envelope combined with a 1 kW PV system, active solar water heating, and passive solar design limit the home’s imported energy needs to a small amount of propane. A detailed report is online at www.nrel.gov/docs/fy04osti/32765.pdf.

Photo: National Renewable Energy Laboratory
Zero-energy has become a buzzword of the green building movement, used in advertising slogans, conference presentations, and technical papers. Despite the excitement over the phrase, however, we lack a common understanding of just what zero-energy means. And despite proclaimed achievability, few if any buildings can demonstrate that they in fact use zero-energy as defined by most practitioners. In this article, we explore the concept of zero-energy: what it means, why it matters, and, most important, how to get there.

 

Published October 1, 2005