Turnkey system
A fuel cell-based project had all the attributes Grossman was looking for—near-zero emissions, extremely low noise, excellent plant energy balance, high system efficiency, and operating simplicity. The main roadblock was the high capital cost, although that blow was softened by cash incentives offered by the California Public Utilities Commission (see "Building without a permit").
A few phone calls later, and after several months of tough negotiations with FCE, SNB ended up buying four, 250-kW DFC300A molten-carbonate fuel cells (Figure 1) that now supply most of the brewery's electrical load. The few kilowatt-hours of excess power that the system produces in winter months are sold back to Pacific Gas & Electric Co. (PG&E).
1. Beer in the making. Sierra Nevada Brewery uses four 250-kW fuel cells to supply the majority of its electrical needs. Heat-recovery units added to the basic system produce process steam, reducing the brewery's natural gas consumption. Courtesy: Alliance Power
To get the system up and running, SNB (www.sierranevada.com) hired Littleton, Colorado-based Alliance Power (www.alliancepower.com)—a firm experienced in fuel cell and gas turbine construction project management. Alliance then formed an ad-hoc affiliate—Alliance Chico Energy—to own the plant; procure the fuel cells; design, build, and integrate the plant with the brewery; operate the plant and sell its output to SNB at a fixed cost (minus the incentives); and handle the interconnection with PG&E. About all that SNB is responsible for is purchasing the natural gas needed to supply the fuel cells.
To supplement the brewery's existing 125-psi steam-supply system, the fuel cell plant design features heat-recovery devices that extract about 1 million Btu/hr of heat (Figure 2). Grossman is keen to point out that, although the fuel cell plant alone is rated at about 50% efficiency, the work of the heat-recovery devices pushes the overall system efficiency to 70%. Such efficiencies may be routine in the not-too-distant future for combined-cycle systems that mate fuel cells with unfired turbines, if FCE and the U.S. DOE have their way (see "Raising the plant efficiency bar").
2. Heat recovery. Energy from the exhaust of the fuel cells is used to produce 125-psi process steam, reducing the load on the plant boilers. Courtesy: Sierra Nevada Brewery
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