Lessons learned in whole-building integrated energy efficiency

In 1990, Pacific Gas & Electric Company initiated a Research & Development project entitled the Advanced Customer Technology Test for Maximum Energy Efficiency (ACT(2)) to determine the maximum energy savings achievable in a customers' facility, at or below utility supply cost, using integrated packages of state-of-the-art energy efficient measures. The theory is that much more energy can be saved through the synergistic interaction of individual energy efficient measures, packaged expressly for that purpose, than would be realized if the measures were implemented individually. For example, a superior building shell and/or glazing will decrease the required size of an air conditioning system such that a smaller, more efficient system can be installed for the same or lower cost than the larger less efficient system. By combining the two energy efficient measures (glazing and a new A/C system), the resulting energy consumption is less than it would be if the measures were evaluated and implemented separately. Nine facilities were ultimately investigated as part of the project, both new construction and retrofit, residential and commercial, with one rear of pre-retrofit (retrofit sites) energy monitoring, implementation of the energy efficient measures and one year of post retrofit energy monitoring. Data collection was completed by the end of 1996. The evaluations of the sites were completed in early 1997. Energy savings ranged from 40% to 509/0 of baseline energy consumption for the retrofit projects to 70% of the projected energy consumption for the new construction sites had they been built to satisfy California's Title 24 energy standards. Although the pending electric industry deregulation has watered down the economic assumptions used, many valuable lessons were learned in the areas of implemented technologies, building and construction industry barriers and energy efficient measure installation techniques as well. This paper discusses some of the major lessons learned in the hope that these barriers and deficiencies can be overcome to create ultra-efficient buildings in the future.