Understanding Zero-Energy Buildings

set a research goal of making commercial zero-energy buildings (ZEBs) marketable by 2025. 1 In concept, a ZEB has greatly reduced energy loads such that renewable energy can supply the remaining energy needs. This immediately begs some questions: " This is a far stretch from our current energy-efficient buildings—is it even possible? " " Are there examples out there that are even close? " To address these questions, the National Renewable Energy Laboratory (NREL) conducted an assessment of the commercial sector to evaluate the technical potential for meeting this goal based on possible technology improvements for 2025. NREL also evaluated seven low-energy commercial buildings to determine with respect to their ability to meet a zero energy goal. 2