Assessment of the Technical Potential for Achieving Zero-Energy Commercial Buildings

Brent Griffith, Paul Torcellini, and Nicholas Long, National Renewable Energy Laboratory
Drury Crawley and John Ryan, U.S. Department of Energy

Keywords

Abstract

The U.S. Department of Energy’s (DOE) Building Technologies Program has adopted the goal of making zero-energy commercial buildings (ZEBs) marketable by 2025. The National Renewable Energy Laboratory (NREL) conducted an assessment of the entire commercial sector to evaluate the technical potential for meeting this goal with technology available in 2005 and projected forward to possible technology improvements for 2025. The analysis looked at the technical feasibility of ZEBs, limitations in market penetration and utility grid structures notwithstanding.

The core of the evaluation was based on creating 15-minute, annual simulations based on 5,375 buildings in the 1999 Commercial Buildings Energy Consumption Survey Public Use Data and the current ANSI/ASHRAE/IESNA Standard 90.1-2004. These baseline-building models were then used to develop alternate ZEB scenarios by applying sets of available technologies and practices and projected improvements after 20 years.

The results show that the ZEB goal is technically achievable for significant portions of the commercial sector. Using today’s technologies and practices, the technical potential is that 22% of the buildings could be ZEBs. With projected 2025 technologies, the technical potential is that 64% of the buildings could be ZEBs. If excess electricity production could be freely exported to the grid, then with the projected 2025 technology in every building, the commercial sector could generate as much as 37% more energy than it consumes. The results suggest that the ZEB goal is feasible for the sector as a whole and that research should be implemented to overcome hurdles to achieving the goal.