This report is the second of a two-part study by Berkeley Lab of a DER (distributed energy resources) system at Navy Base Ventura County (NBVC). First, a preliminary assessment of the cost effectiveness of distributed energy resources at Naval Base Ventura County (NBVC) Building 1512 was conducted in response to the base s request for design assistance to the Federal Energy Management Program (Bailey and Marnay, 2004). That report contains a detailed description of the site and the DER-CAM (Consumer Adoption Model) parameters used. This second report contains sensitivity analyses of key parameters in the DER system model of Building 1512 at NBVC and additionally considers the potential for absorption-powered refrigeration.The prior analysis found that under the current tariffs, and given assumptions about the performance and structure of building energy loads and available generating technology characteristics, installing a 600 kW DER system with absorption cooling and recovery heat capabilities could deliver cost savings of about 14 percent, worth $55,000 per year. However, under current conditions, this study also suggested that significant savings could be obtained if Building 1512 changed from its current direct access contract to a SCE TOU-8 (Southern California Edison time of use tariff number 8) rate without installing a DER system. Evaluated on this tariff, the potential savings from installation of a DER system would be about 4 percent of the total bill, or $16,000 per year.

This paper reports the findings of a preliminary assessment of the cost effectiveness of distributed energy resources at Naval Base Ventura County (NBVC) Building 1512. This study was conducted in response to the base's request fordesign assistance to the Federal Energy Management Program. Given the current tariff structure there are two main decisions facing NBVC: whether to install distributed energy resources (DER), or whether to continue the direct access energy supply contract. At the current effective rate, given assumptions about the performance and structure of building energy loads and available generating technology characteristics, the results of this study indicate that if the building installed a 600 kW DER system with absorption cooling and heat capabilities chosen by cost minimization, the energy cost savings would be about 14 percent, or $55,000 per year. However, under current conditions, this study also suggests that significant savings could be obtained if Building 1512 changed from the direct access contract to a SCE TOU-8 (Southern California Edison time of use tariff number 8) rate without installing a DER system. At current SCE TOU-8 tariffs, the potential savings from installation of a DER system would be about 4 percent, or $15,000 per year.

While demand for electricity continues to grow, expansion of the traditional electricity supply system, or macrogrid, is constrained and is unlikely to keep pace with the growing thirst western economies have for electricity. Furthermore, no compelling case has been made that perpetual improvement in the overall power quality and reliability (PQR) delivered is technically possible or economically desirable. An alternative path to providing high PQR for sensitive loads would generate close to them in microgrids, such as the Consortium for Electricity Reliability Technology Solutions (CERTS) Microgrid. Distributed generation would alleviate the pressure for endless improvement in macrogrid PQR and might allow the establishment of a sounder economically based level of universal grid service. Energy conversion from available fuels to electricity close to loads can also provide combined heat and power (CHP) opportunities that can significantly improve the economics of small-scale on-site power generation, especially in hot climates when the waste heat serves absorption cycle cooling equipment that displaces expensive on-peak electricity. An optimisa-tion model, the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed at Berke-ley Lab identifies the energy bill minimising combination of on-site generation and heat recovery equipment for sites, given their electricity and heat requirements, the tariffs they face, and a menu of available equip-ment. DER-CAM is used to conduct a systemic energy analysis of a southern California naval base building and demonstrates a typical current economic on-site power opportunity. Results achieve cost reductions of about 15 percent with DER, depending on the tariff. Furthermore, almost all of the energy is provided on-site, indicating that modest cost savings can be achieved when the microgrid is free to select distributed genera-tion and heat recovery equipment in order to minimise its over all costs.

This report describes an investigation at Ernesto Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) of the potential for coupling combined heat and power (CHP) with on-site electricity generation to provide power and heating, and cooling services to customers. This research into distributed energy resources (DER) builds on the concept of the microgrid (mGrid), a semiautonomous grouping of power-generating sources that are placed and operated by and for the benefit of its members. For this investigation, a hypothetical small shopping mall ("Microgrid Oaks") was developed and analyzed for the cost effectiveness of installing CHP to provide the mGrid's energy needs. A mGrid consists of groups of customers pooling energy loads and installing a combination of generation resources that meets the particular mGrid's goals. This study assumes the mGrid is seeking to minimize energy costs. mGrids could operate independently of the macrogrid (the wider power network), but they are usually assumed to be connected, through power electronics, to the macrogrid. The mGrid in this study is assumed to be interconnected to the macrogrid, and can purchase some energy and ancillary services from utility providers.