U.S. Army

EXECUTIVE SUMMARY [Continue to full document]

The purpose of the preliminary site assessment is to determine if Picatinny Arsenal has the desired characteristics to be selected for the "Demonstration of Natural Gas Engine Driven Air Compressors at Department of Defense Industrial Facilities" (NGEDAC) initiative. The NGEDAC initiative is managed by the U.S. Army Construction Engineering Research Laboratory (CERL) and is being implemented by TMS, Inc. and XENERGY, Inc. under Contract/Delivery Order Number DACA 88-98-D0007-0002. The site assessment was conducted by TMS/XENERGY personnel during the week of August 28th, 2000.

The preliminary assessment provides an overview of the facility's compressed air system, outlines potential areas for reducing system demand, evaluates the general economics of a gas driven system at the site, and identifies potential benefits or problems associated with implementing a gas driven system. The preliminary assessment concludes that the Picatinny Arsenal is a good candidate for additional consideration as a demonstration site.

Current air flow of the main system is approximately 925 acfm at a supply pressure of 80 psig with an annual energy cost of $100,000. This figure is a reduction of $25,000 that had been previously achieved by operating personnel who lowered the final discharge pressure to the system from 100 psig to 80 psig.

In moving forward, potential reductions in air leaks and the level of production air supplied during non-production periods could decrease air requirements by 500 acfm or an additional $42,000, leaving an annual energy bill of $58,000. Such a reduction level is realistic and will be verified by a leak study if the Picatinny site is selected for a Detailed Assessment Study.

Other demand-related aspects that will be investigated in a Detailed Assessment Study are the feasibility of shutting down the main system during non-production periods, closing off sections of the distribution system instead of repairing the associated leaks, and reviewing several cost saving opportunities associated with the Arsenal's subsystems for compressed air.

The Picatinny site demonstrates favorable economic conditions for implementation of a gas engine driven system. Such a system is estimated to save $32,000 annually in fuel costs based on an interruptible gas supply price of $3.41 per million Btu. The gas driven engine system would incur $11,000 in incremental annual maintenance costs based on a two-year maintenance contract for the gas system. The resulting net operating cost of the gas system is $21,000 less than the current electric system.

Preliminary estimate of the installed system cost for the gas technology is approximately $160,000. This estimate could vary up or down depending on specific installation conditions and/or desired equipment features. For example, an air-cooled engine feature would add about $4,000 to the system cost, but may be otherwise beneficial. System environmental emission levels are based on limits of 0.70 gm/bhp/hr for NOx and 0.48 gm/bhp/hr for CO.

The total estimated project cost does not include any potential electrical demand reduction rebates for which this project may qualify. This issue will be investigated during the Detailed Assessment Study and after the Arsenal has obtained approvals for the TMS Team to discuss such opportunities with the appropriate utility or state staff.

Other supply-related issues to be investigated in a Detailed Assessment phase include definitively firming final price of natural gas, addressing potential environmental issues that currently appear to be minimal, and finalizing the overall equipment requirements so price estimates can be formalized.

The Picatinny site has a number of other positive aspects that help make it a good demonstration site candidate. Gas supply is readily accessible. Physical space is available and plant modifications would be minimal. Experience and confidence gained by Arsenal staff and contractors in developing and operating the 2.2 MWe gas-fueled cogeneration system are a significant plus and may help reduce cost estimates for maintenance contracts for the gas engine compressed air system.

The Picatinny site provides for a fairly straightforward technology application and demonstration with a very manageable system size. It affords the Department of Defense an excellent opportunity to test operating a "gas/electric hybrid system." In addition, the Arsenal would be provided an opportunity to gain experience in using energy savings performance contracting (ESPC) vehicles for implementing the recommended system optimization improvements which are outside the scope of this NGEDAC project, but are essential in properly sizing the project's gas engine system and reducing the overall operating costs of Picatinny Arsenal.