The California Public Utilities Commission is pursuing zero net energy buildings in the commercial and retail sector as a way to increase energy efficiency and cut the future need for electricity. The move\u2014discussed during a public workshop at the commission June 5 and 6\u2014embraces the American Institute of Architect\u2019s \u201c2030 Challenge.\u201d That architectural strategy seeks to cut building energy use by 50 percent immediately, then starting in 2010 by another 10 percent every five years until new structures are \u201ccarbon neutral\u201d beginning in 2030. Today, buildings consume 48 percent of the nation\u2019s energy, according to Ed Mazria, Mazria Odems Dzurec partner and inventor of the 2030 Challenge. However, most of those buildings will be replaced or renovated over the next 30 years, he notes, opening an opportunity to cut energy use and greenhouse gas emissions dramatically. Net zero energy buildings are defined as those which are carbon neutral. They typically employ enough energy efficient design features, fixtures, appliances, insulation, windows, and photovoltaic panels that they can feed the grid as much energy as they draw when averaged over a year. Southern California Edison endorsed the concept, but pointed out that the biggest challenge will be to achieve zero net energy use on big buildings, particularly those in hot inland areas of the state. So what\u2019s involved in building a zero net energy building and will it work in hot desert areas? A National Renewable Energy Laboratory Study, Assessment of the Technical Potential for Achieving Zero-Energy Commercial Buildings, sheds light. The 2006 study found that by using \u201ccurrently available\u201d technologies and design features, 22 percent of new commercial buildings representing 23 percent of commercial building floor space nationally could achieve net zero energy use. In inland portions of California, 38 percent of commercial floor space could achieve the zero net energy use mark. These technologies include: -Covering half of roof space with solar panels; -Placing exterior fixed overhangs over glass on the south facing side of buildings; -Installing \u201csuper insulation and super windows;\u201d -Using centralized chilled-water-based air conditioning with advanced efficiency features and highly efficient gas heating; and -Installing the most efficient lighting systems available. The report said increases in the efficiency of photovoltaic panels, lighting, and the wide range of electronic devices used in buildings\u2014from appliances to computers\u2014will be needed to enable more commercial structures to operate as zero net energy buildings.