Overview
California State University, Northridge (CSUN) has established itself as one of the nation's leading academic institutions in taking action to reduce global warming. To help the university meet its goals for greater energy independence, cost management and increased use of green power, CSUN called on P2S to help with the installation of an ultra-clean fuel cell power plant— within a combined heat and power application.
Challenge
CSUN’s drive to fund this project was due to the CSU’s Policy Statement on Energy Conservation, Sustainable Building Practices, and Physical Plant Management for CSU and the California Assembly Bill AB32, The Global Warming Solutions Act. P2S worked with CSUN physical plant management team and CSUN professors and students to develop the design/build plans for the project.
Fuel cells are among the cleanest, most reliable sources of power generation today. They provide continuous high-quality power 24 hours-a-day, with ultra-low emissions and quiet operation. The heat byproduct can be used in cogeneration applications that can heat or cool buildings. Even more, fuel cell power plants lower the demand for power from local utilities, further reducing greenhouse gas emissions that would have been produced by generating the electricity at conventional power plants.
Action
P2S served as the engineer of record and developed the civil, mechanical and electrical design for the facility. CSUN physical plant staff constructed the plant. The CSUN physical plant management team provided project management. All work was completed within a one-year time frame.
The 1-MW, natural gas-fed Direct FuelCell (DFC) 300MA plant, manufactured by FuelCell Energy Inc., includes four fuel cells and supplies 18% of the campus’ electricity needs. Furthermore, it allows the campus to build its infrastructure more quickly to serve new building construction.
The fuel-cell plant has been married to a 2,000-ton satellite chiller plant built in the adjacent reconditioned 1957 steam plant. P2S also designed this project. The power generated by the fuel cells drives two variable speed, 1,000-ton chillers. The fuel-cell plant connects and operates in parallel with the campus’ high voltage infrastructure and the local utility grid. A barometric thermal trap was provided to recover waste heat. Nicknamed “The Birdhouse” because of its appearance, it gathers the multiple waste-heat streams from each of the four fuel cells, where the waste heat exits at 650°F to 750°F. The waste streams are mixed and then drawn through the barometric thermal trap where the waste heat travels across the first-stage heat-recovery coil giving up most of its heat—dropping to 170°F. The heated water is then fed into the existing underground campus heating hot water loop that provides heat to campus buildings.
A separate loop, taken from the exhaust heat, passes over the latent heat-recovery coil until reaching a condensing temperature of 140°F. This loop continues to the nearby student union where it heats domestic hot water and swimming pool water.
Another significant innovation is the plan to recycle the carbon dioxide, a byproduct of the natural-gas reformer that extracts hydrogen in the fuel cell cycle, from the fuel cells’ waste heat, thus contributing another sustainable element to the fuel-cell plant. While most carbon-dioxide savings are credited to the fuel cells’ non-combustion fuel-reformation process and the plant’s high efficiency, the exhaust is still relatively rich in carbon dioxide. So, trace amounts of carbon dioxide entrained in the condensing steam, forming a 5.0-pH condensate, are used for research at the campus greenhouse and for landscape irrigation. A distribution system pulls side stream flows of condensate at selected volumes from the recovery chamber and direct them over the roof of the satellite chiller facility to the nearby greenhouse.
As part of the university’s future carbon-dioxide-enrichment research program the condensate, rich in carbon dioxide, will enrich plant growth through photosynthesis. In conjunction with the 2,000-ton satellite plant, the university will create a subtropical rain forest in a corner of the campus— just a few hundred feet from the fuel-cell plant and satellite chiller facility. A second side stream of condensate will be directed through a diffusion distribution system through the rain forest microclimate to provide irrigation and enhance photosynthesis.
Results
- The fuel cell and chiller plant provides Cal State Northridge annual net energy cost savings (electric and thermal) of $235,000 with a net combined savings of $14.5M over 25 years
- The plant generates approximately 8,333,000 kilowatt hours of electricity annually—approximately 18 percent of the campus' base-load power requirements
- Produces 22 billion British Thermal Units (BTUs) of thermal energy per year in the form of usable hot water—enough energy to heat and cool 45 large homes in a harsh climate for an entire year
- Rates a combined heat and power efficiency of 83 percent, meaning that proportion of the energy stored in its fuel is captured and recovered -- either as electricity or usable thermal energy. For perspective, the U.S. electrical grid today has an efficiency of fewer than 40 percent
- Produces virtually no NOx, CO, SOx, volatile organic compounds or particulate emissions; while the average U.S. fossil fuel power plant produces nearly 25 pounds of these emissions per megawatt hour, the DFC fuel cell produces just 0.1 pounds of these emissions
- Reduction of over 100 tons of harmful emissions annually
- Reduces greenhouse gas emissions by 69 percent—compared to greenhouse gas emissions generated by California's electrical grid portfolio of hydro, coal, natural gas, nuclear and renewable sources
- The facility eliminates the emission of more than 6,400 tons of CO2 into the environment per megawatt year
- The client was pleased with the results and innovation from the design/build approach to the project and the interaction between P2S and CSUN physical plant, CSUN professors and CSUN students throughout the entire design process
