Critical Load Renewable Energy Microgrid
Marine Corp Logistics Base, Albany GA
Long Term Islanding Microgrid
Marine Corps Logistics Base, Albany (MCLB) is home to the Marine Corps Logistics Command, the Marine Depot Maintenance Command, and Maintenance Center Albany (MCA). MCA is a production plant that repairs or remanufactures Marine Corps ground combat and combat support equipment and other similar types of equipment. Electrical supply to this facility is critical since the mission of the facility is dedicated to supporting the warfighter by providing high quality and timely services to its tenant commands. Any outages to either electrical or thermal energy can severely disrupt production and mission objectives.
MCLB’s energy goals are to provide its service members and their families, and civilian employees, a safe, reliable, and secure workplace with energy usage that meets Presidential and Congressional mandates and reduces greenhouse gas emissions while increasing its use of alternative energy sources. Increased energy surety and resiliency, using environmentally sound resources, is MCLB’s ultimate goal.
PowerSurety principals, working as employees of Chevron USA Inc. at the time, led a business organization and the project team that developed, designed, built, financed, and operated a unique Public-Public-Private-Partnership-based (P4) methane-derived landfill gas-to-energy (LFGE) combined heat and power (CHP) microgrid project at MCLB Albany. The project increased energy security and reliability, brought renewable energy generation to 22 percent of total energy consumed, and provided islanding capability for onsite mission critical loads. In addition to accomplishing the above, and at the same time, the project team was able to lower operating costs for the facility; a significant and remarkable achievement.
Due to the project’s unique technology approach, commercial structure, operational impacts, and risk profile, PowerSurety principals guided the development team through the project’s planning, development, engineering, economic and cost/pricing analysis, structured financing, and contract negotiation/award processes over a multi-year period.
MCLB Albany is also home to the U.S. Department of Navy’s first renewable methane-derived LFGE CHP microgrid project that resulted from a Public-Public-Private Partnership (P4) involving three government agencies and one private sector company. The project was developed under the U.S. Department of Energy’s (DOE) Energy Savings Performance Contracting (ESPC) program with two federal agencies, DOE and the U.S. Department of Defense; one local government agency, Dougherty County, Georgia; and Chevron USA Inc.
In order to provide renewable fuel to the new onsite CHP microgrid that would serve mission critical loads, Dougherty County entered into a methane off-take agreement with MCLB Albany. Instead of flaring excess landfill-derived methane as they’d previously been doing, Dougherty County elected to reduce its greenhouse gas emissions by capturing and diverting the methane for a beneficial purpose that also served to create a new revenue stream for the County.
Landfill gas (LFG) is provided from Dougherty County’s landfill, located adjacent to the Base, with a compression and dehydration station located on County property at the landfill. The subsurface LFG pipeline that Chevron funded, designed, and built, transports methane from the compression station to the new CHP plant located on MCLB property approximately four miles away. The facility contains a dual-fuel Jenbacher reciprocating engine generator, a stack heat recovery steam generator, two dual-fuel boilers, and the switchgear necessary to convert the LFG into energy for the MCA facility, which is MCLB’s largest energy consumer.
Customer requirements for islanding capabilities for both thermal and electrical energy during outage events led to configuring the 6 MW total CHP (4 MW thermal and 2 MW electrical output capacity) into an MCA-wide microgrid. The CHP utilizes LFG as its primary fuel source and is backed with natural gas.
Thermal energy is supplied as steam to an MCLB central plant to offset the standalone natural gas-derived generation of steam for distribution throughout the installation. Biogas is used in a combination of boilers and a heat recovery steam generator (HRSG) to afford MCLB maximum flexibility for fuel switching. This Multi-Fuel / Multi-Unit / Multi-System strategy maintains availabilities of thermal energy supplied to critical loads at high levels. Thermal generators consist of two 12.5 MMBtu boilers and one 5.5 MMBtu HRSG in addition to the existing boiler plant, which remains intact for purposes of system redundancy. Biogas boilers have fuel mixing capabilities to accommodate steam production with varying ratios of biogas and natural gas.
The project also provides ancillary energy surety benefits since it displaces 19 percent of the Base’s purchased natural gas and electricity, and also reduces the Base’s energy intensity by 16 percent. This reduction in baseline energy use, combined with microgrid-enabled distributed generation, provides for increased energy security and reliability. The renewable energy microgrid can operate in parallel with the utility grid or in island mode, and can run using either straight LFG or with an LFG-natural gas blend. In the event of an electrical grid outage, the generator can operate on 100 percent natural gas, providing onsite power to support critical requirements and loads. Additional details for the project are shown below:
CHP Microgrid System Features
- Electrical Generation: 1.9 MW
- Thermal Generation: 3,100 PPH
- GE Jenbacher Reciprocating Engine w/ Heat Recovery
- Environmental Benefits: GHG Reduction by 19,200 TPY
- Simple Payback: 14 Years
- 150 BHP Johnston Boilers
- Webster Burners
- Fuel: Landfill & Natural Gas
- Emissions Control: LEANOX Combustion Control
- Efficiency: 50%