Towards a Net Zero Building Cluster Energy Systems Analysis for US Army Installations

Abstract

Abstract : U.S. federal agencies are required by law to eliminate fossil fuel use in new and renovated facilities by 2030, and to reduce overall facility energy usage by 30% by 2015 (EISA 2007). Army policy is to achieve 5 net zero energy installations by 2021, 25 net zero energy installations by 2031 and for all installations to achieve net zero energy status by 2058. The Army operates what are essentially small campuses, or clusters of buildings on its installations. The US Department of Energy (DOE) is focused on the national grid scale or on individual buildings, while the commercial focus is on retrofits to individual buildings. There is a lack of tools and there are only few case studies worldwide that address dynamics of energy systems at the community scale. The Army's future building energy requirements is a mixture of ultra-low and high energy intensity facilities. Achieving net zero energy economically in these clusters of buildings will require a seamless blend of energy conservation in individual buildings and building systems automation, utility management, and control, power delivery systems with the capability to offer integration of onsite power generation (including renewable energy sources) and energy storage. When buildings are handled individually each building is optimized for energy efficiency to the economic energy efficiency optimum and then renewables are added until the building is net zero. This process works for buildings with a low energy intensity process for its mission, such as barracks and administrative buildings. When the mission of the building requires high energy intensity such as in a dining facility, data center, etc., this optimization process either will not end up with a net zero energy building, or large amounts of renewables will be added resulting in the overall technical solution that is not cost effective.