Ameresco & Department of Energy Savannah River partnered together to install three biomass fueled energy plants. The main plant is a 20 megawatt steam power plant and the other two smaller plants are thermal heating plants. All three facilities are located on the Department of Energy Savannah River Site (SRS). These facilities were developed and financed under an Energy Savings Performance Contract (ESPC), which utilizes energy and operational savings to fund the capital investment and operations cost over the performance period. Ameresco was fully responsible for the design, installation, oversight, management, safety, environmental compliance, and continues to be responsible for the operations and maintenance of the Biomass Cogeneration Facility. This is the largest biomass facility installed under ESPC in the federal government.
The facilities have the capacity to combust 385,000 tons of forest residue annually. In the first year alone, the energy and operation cost savings at SRS is in excess of $34 million.
Clean biomass and bio-derived fuels (such as tire derived fuel and untreated pallets) is the primary fuel source for all of the new boilers. Biomass is used to fuel two steam boilers capable of producing 240,000 lb. /hr. of high-pressure steam and to power a steam turbine capable of generating up to 20 MW of electricity. The smaller thermal plants provide biomass-produced steam for the areas’ heating and industrial processes. These plants satisfy winter steam requirements for both domestic heat and process steam and is fueled solely with biomass wood chips, utilizing fuel oil as backup source of fuel.
Key benefits of the SRS biomass project include:
• Over 2,000,000 MBtu/yr. of thermal renewable energy production and a minimum of generation of 77,000,000 kWh of green power
• Annual Energy Reductions of approximately 500,000 MBtu/yr.
• No-cost Renewable Energy Credits retained by the DOE SR
• Support of the South Carolina Biomass Council Goals
• Decrease of water intake from the Savannah River by 1,400,000 kgal/yr., supporting water conservation efforts in the region
• Reduction of 400 tons/yr. of Particulate Matter (PM) emissions
• Reduction of 3,500 tons/yr. of Sulfur Dioxide emissions
• Reduction of 100,000 tons/yr. of Carbon Dioxide emissions
The smaller heating plants include the main boiler systems and live bottom trailer fuel storage. The Biomass Cogeneration Facility includes the biomass boiler systems, the steam turbine generation system, and the facility auxiliary systems as well as the site infrastructure within these boundaries. The Facility has been designed, built, and tested per industrial/commercial codes for cogeneration facilities. The main components of the Facility are listed below:
• Fuel Yard – Material Unloading & Storage and Delivery System
○ Biomass Fuel Chip unloading system
○ Fuel Storage Area
○ Transfer conveyors
○ Fuel Screening System
○ Tire Derived Fuel Storage & Unloading Area
○ Whole Log Chipping System & Storage
• Water Treatment System – Water treatment system to treat river water for use in boilers as well as cooling tower for condensing turbine
• Boiler Systems – (2) Boiler Island from metering bin, water side and flue gas side, pollution control devices and stacks
• Chemical Treatment System – Chemical skids, injection skids for cooling tower and boiler treatment
• Steam Turbine Generator System & Turbine Cooling System – (1) steam turbine and generator & Cooling Tower with cooling tower pumps
• Emergency Generator System – (1) back diesel generator
• Plant Control System – Master SCADA system which integrates all systems and balance of plant equipment I/O into one control system