Technology Description

NZEI is the product of an Army-funded applied research program that melds the experience gained in conducting energy projects on Army installations with advanced analytical methods for optimizing complex energy systems at a community level. Once installation data has been set up, the system identifies types of buildings by category code and era of construction. NZEI proposes and analyzes appropriate packages of EEMs using automated runs of the EnergyPlus whole building energy simulation package. Simulation runs are conducted on a back-end server farm, and results are stored for future reuse, making NZEI faster and more responsive as more installations are analyzed. Data from these simulations is combined with EEM cost estimates to generate cost-savings curves.

Optimized individual buildings are analyzed with decentralized systems (business-as-usual) or they can be connected to co-generation or renewables serving either the individual building or a cluster of buildings. This option requires a different (higher or lower) level of investment compared to the cost of decentralized boilers and chillers for single buildings and that of larger renewable generation equipment, but will result in significant fossil fuel reduction due to use of waste heat accompanying electricity generation. This heat can be used to satisfy heating, cooling, and domestic hot water needs of the building cluster or exported to another building cluster. The amount of waste heat generated will determine the optimal level of the building insulation and its loads. When the boundaries of the analysis go beyond a single building, the waste heat can be used for the building clusters under consideration, and the decision on the level of building insulation (and other EEMs) must be made based on a mix of buildings (new and old) and on other potential uses of waste heat. When biomass or biogas is used as a fuel, the connected buildings become net zero with respect to fossil fuel consumption. Typically, when buildings are connected to combined heat and power (CHP) plants, they do not require additional thermal energy from renewable energy sources but may require additional electrical power.