Abraxas Energy Consulting conducted an energy assessment for Bremerton Naval Hospital in Bremerton, Washington in August 2013. There are 5 buildings in the scope of this project at this facility: a 24,799 square foot building which 3rd floor will serve as a dental clinic (B-506), three health clinics of 29,868 square foot, 32,801 square foot and 32,780 square foot respectively (B-940, B-2010 and B-2050), and a 17,425 square foot health and education center (B-2850). The goal of the audit was to assist Bremerton in identifying and developing energy investment initiatives that achieved the federally required energy reductions.
The energy assessment was performed in two phases, a Preliminary Assessment (Phase 1) and a Scoping Energy Assessment (Phase 2). Phase 1 consisted of a utility bill audit which established a baseline for energy and water usage and facilities benchmarking using energy Star Portfolio Manager. Twelve months of bills for water and gas, and electricity were used to conduct the audit. This generated a baseline for the energy/water/gas usage and utility costs, which was used in calculating potential energy savings. Energy Star scores ranged from 21 for one of the health clinics to 51 at the dental clinic and the goal after implementation of conservation measures was to reach a score of 75. The calculated HDDs and CDDs provided insight to potential energy conservation measures.
The second phase used on-site visits with the purpose of identifying and quantifying cost-effective energy efficiency measures, water conservation practices and renewable energy measures. During the on-site inspection all the relevant information on the existing building conditions was collected. This on-site assessment included reviewing building and equipment data, interviewing site personnel, observing energy related equipment operation, and conducting some limited site measurements. Based on the inspection and calculations fourteen ECMs were recommended, as well as a list of administrative and operational measures that could be also implemented.
The largest opportunity for savings was found on eliminating unnecessary runtime of HVAC systems by scheduling occupied and unoccupied setpoints in the existing EMS system of the three health clinics. Other ECMs found, affecting all or some of the analyzed buildings, were lighting upgrade and controls, adjustment of server room thermostats, installation of flow regulators on restroom faucets, PC management software installation, time and temperature control of the hot water pump , and installation of electronic valves and programmable thermostats for the hot water radiator. Studies were also conducted into the feasibility of co-generation, renewable energy sources and retro-commissioning. These were preliminary assessments and based on the results, co-generation and renewable energy sources were not found to be cost effective, but retro-commissioning of some of the systems was found to be cost effective and even critical to fully realizing the savings for many of the recommended efficiency measures. So even though a full retro-commissioning is not recommended, the implementation of some individual measures is highly encouraged. The existing and proposed annual energy usage and cost for this project are shown below.
When implemented, the ECMs will save over $57,062 per year with a simple payback of 1.2 years. The list of measures is prioritized by simple payback such that short term investments are expected to be implemented first and longer term investments implemented last. Some interactive effects are accounted for in the calculation of energy savings such that if a different implementation sequence is followed the savings realized will vary to a degree. Total savings for electricity is 511,398 kWh/yr, for gas the savings is 467 Therm/yr, for steam/hot water savings is 505 MMBtu/yr and for water savings is 143 MGal/yr. Total energy savings results in a 22% reduction in energy intensity. All values were evaluated using bin simulations and spreadsheet calculations based upon standard energy savings estimating methods and known and assumed operating conditions. Various incentives were identified through utility companies and various federal programs.