SC Johnson Waxdale Plant - 6.4 MW CHP System - Case Study
LOCATION: Racine, Wisconsin
MARKET SECTOR: Manufacturing
FACILITY SIZE: 2.2 Million Square Feet
(1) 3.2 Megawatt Landfill Gas Turbine
(1) 3.2 Megawatt Natural Gas Turbine
FUEL: Landfill Gas and Natural Gas
DISTANCE FROM RENEWABLE FUEL SOURCE: 2/3 of a Mile
CHP GENERATING CAPACITY: 6.4 Megawatts
HEAT RECOVERY RATE: 40,000 lbs/hr Steam
HEAT RECOVERY SOURCE: (2) Heat Recovery Steam Generators (HRSGs)
Annual Operating Hours: 8,760
CHP TOTAL EFFICIENCY: >70%
PAYBACK: 6 years
2003 (Landfill CHP System)
In 2003, as part of SC Johnson’s ongoing commitment to protect the environment, a landfill gas-fired 3.2 MW Solar Centaur 40TM combustion turbine was installed at the SC Johnson Waxdale Plant, located in Racine, Wisconsin. The landfill gas is generated at a nearby landfill site, located 2/3 of a mile from the Waxdale plant. Designed and installed by Northern Power Systems, the 3.2 MW combined heat and power (CHP) system reduces fossil fuel electrical power demand while producing 17,000 lbs/hr of 150 psi process steam through a heat recovery steam generator (HRSG).
In 2005, SC Johnson added a second 3.2 MW Solar Centaur 40TM combustion turbine, fueled primarily by natural gas. The second turbine recycles the exhaust heat from the turbine through a HRSG and produces an additional 23,000 lbs/hr of process steam.
Today, the combined 6.4 MW CHP plant provides the base load of electricity for the 2.2 million square foot manufacturing facility while providing up to 40,000 lbs/hr of high quality steam for heating and manufacturing processes. The two turbines together achieve an overall energy efficiency of more than 70% (electrical and thermal).
As waste in landfills decomposes, a gas is produced consisting of methane (CH4), carbon dioxide (CO2) and other gases and compounds. Republic Service Kestrel Hawk landfill flared the generated gas.
As part of SC Johnson’s commitment to the environment, the company became a member of the Environmental Protection Agency’s (EPA) Climate Leaders Program. As a member, of this program, SC Johnson set out to reduce their greenhouse gas emissions at their U.S. facilities by 8% (absolute reduction) between the years 2000 and 2005. Being one of SC Johnson’s largest plants, the Waxdale plant was a prime candidate for an energy efficiency feasibility study. Several technologies were considered for the plant’s energy supply including wind and solar power, geothermal heat pumps, and landfill gas combustion for heating needs. Installing a CHP system that utilized nearby landfill gas proved to be the best solution for the Waxdale plant, providing the greatest impact towards the overall greenhouse gas reduction goal and realizing the biggest “bang for the buck”.
Satisfied with the first turbine’s installation, operation and performance, SC Johnson decided to install a second turbine, this one primarily fueled by natural gas, to produce more on-site clean energy. The second turbine, in combination with the first turbine, has reduced the overall plant emissions annually by 52,000 tons of CO2, saving 298 railcars of coal from being burned to generate electricity in Wisconsin annually. Also due to the installation of these two turbines, SC Johnson was able to exceed their U.S. emission reduction goal by achieving an absolute reduction by 17%.