The client, a world-wide manufacturer and supplier of passive electronic components and interconnects, has a manufacturing facility in El Salvador comprised of eight factory buildings encompassing over 420,000 square feet. The campus is not a single consolidated campus; rather, various buildings throughout a neighborhood were acquired and modified over time. Over 300 employees work during a typical day. The campus spends over $12,000,000 in electricity and $800,000 in diesel each year. Our client desired to identify efficiency measures to reduce their energy costs.
Abraxas Energy Consulting performed an energy audit on the eight facilities at the AVX El Salvador campus. Initially, a utility bill analysis was conducted to establish a baseline for energy usage, to determine if alternate rates were available, and to identify any billing errors. Twelve months of bills for electricity and diesel were used to conduct the analysis. The generated baseline and utility costs were used to calculate potential energy savings. The utility analysis also showed that there was no correlation between monthly electricity consumption and weather or production output, and that diesel consumption remained relatively constant from month to month. Additionally, one month of 15-minute interval data was analyzed to determine which manufacturing processes were the most energy intensive.
While on-site, engineers investigated each facility’s lighting and mechanical systems including HVAC, building controls, refrigeration systems, and manufacturing processes. During the investigation, relevant information on each building’s existing condition was collected. The assessment included reviewing building and equipment data, interviewing site personnel, and observing energy related equipment operation. A list of energy conservation measures (ECMs) was produced that, when implemented, could reduce energy usage and costs. These energy saving measures were explained in a detailed report which included a description of the existing condition and measure description, in addition to associated installation costs, savings, and simple paybacks.
Altogether, Abraxas identified 24 ECMs totaling $1,986,261 in savings. The largest opportunities for savings were found in revising the AHU controls at each facility, and designing and implementing a combined cooling, heating, and power plant (CCHP). Other identified ECMs included lighting upgrades, control upgrades, installation of insulation in ovens and processing tanks, upgrading the cold storage room refrigeration system, and installing a solar photovoltaic system. Several low-cost or non-efficiency related operation and maintenance (O&M) measures were also identified and included in the report. O&M measures included relocating storage boxes in the warehouse cold storage rooms to improve air flow, replacing dirty air filters, removing broken or retired HVAC equipment, and sealing cracks or holes in building envelopes.
When implemented, the ECMs will save over $1,986,261 per year with a simple payback of 2.8 years. Total savings amounts to 12,610,138 kWh/yr in electricity, 1,199 kW/peak in electric demand, and 522,933 gal/yr in diesel. However, the campus is expected to consume an additional 1,057,283 gal/yr in propane due to implementing the CCHP and utilizing a propane-fired boiler. Water usage is also expected to increase by 21,135 kGall/yr by implementing the CCHP and installing a roof evaporative cooling system. Total energy savings results in a 6% reduction in energy use. All values were evaluated using spreadsheet calculations and bin simulations based upon standard energy savings estimating methods and known and assumed operating conditions.