Abraxas Energy Consulting was contracted by Northrop Grumman to conduct an ASHRAE Level 2 audit, an in-depth analysis of boilers and compressed air systems, as well as a submetering feasibility study throughout seven buildings (including manufacturing, lab, office, and storage spaces) at their Elkton, Maryland campus. The Elkton campus includes 180 buildings, covering more than 600 acres.
Before the first site visit, utility data and existing building documentation were reviewed for a better understanding of how the facility currently functions. The on-site assessment included reviewing building and equipment data, interviewing site personnel, observing energy-related equipment operation, HVAC systems, lighting, building envelope, and water/plumbing systems. The boiler analysis and compressed air analysis involved going through the building automation system (BAS) and reviewing trend data from the past year. Buildings and key processes were also evaluated for possible submeter installations.
Abraxas identified 23 energy and water savings measures, which included installing variable vacuum speed stations, replacing dry-type transformers with DOE-16 rated transformers, multiple compressed air repairs and improvements, updates to the BAS and HVAC systems, and many more. Once implemented, the ECMs will result in an annual cost savings of $96,000, with a simple payback of 2.6 years. Overall energy and water savings include 751,619 kWh per year in electricity, 48,589 therms per year in natural gas, 109 kGal per year in the sewer, and reducing their peak load by 42 kW.
The compressed air analysis specifically looked at energy-saving measures such as waste heat recovery, installing zero-loss condensate drains, and scheduling and optimizing the operation of the current systems. One of the most notable recommendations was for an air compressor serving three of the plant’s autoclaves. The compressed air analysis showed that some of the autoclave heat cycles do not use any compressed air, but the compressed air system was running any time the autoclaves were operating. The autoclaves are operated by programmable logic controllers (PLC). This measure recommends having the PLC control not only the autoclaves but also the compressed air supply. Installing a programmable isolation valve on the compressed air line and having that be controlled by the PLC will ensure that compressed air will only be used when needed. Once completed, this upgrade will save nearly $14,000 per year in energy costs.
At the time of the audit, many of the buildings at the Elkton, Maryland facility were on the same master electrical meter. Abraxas worked with Northrop Grumman to develop a plan for installing forty-two submeters throughout the facility to better understand how and where energy is being consumed. Abraxas provided calculations and scopes of work for each contractor that would be required for installation. Drawings were also completed showing where each proposed new submeter was to be installed.