West Lafayette WWTP

At a Glance
• System Configuration: 2 × C65 Grid Connect Capstone Biogas Microturbines with Unison Solutions gas conditioning
• Annual Generation: >1,000 MWh/year of clean, renewable electricity
• Thermal Output: 860,000 BTU/hr of recovered hot water for anaerobic digester heating
• Financial Impact: ~$100,000 / year in direct utility savings plus revenue from tipping fees
• Fuel Source: Co-digested biogas (fats, oils, grease [FOG], food scraps, and sludge)
• Sustainability & Service: Member of EPA Green Power Partnership; commissioned in 2009 and serviced by Veristar since 2020


The Challenge
Operating a 9 MGD activated sludge facility, the West Lafayette Wastewater Treatment Plant in Indiana faced high continuous electrical demand and heavy heating loads for its anaerobic digesters. To align with environmental goals as an EPA Green Power Partner and lower municipal operating budgets, the city sought to replace 50-year-old digesters and eliminate dependence on legacy natural gas boilers by converting organic waste streams into clean on-site power and heat.


The Solution
A 130 kW Combined Heat & Power (CHP) system featuring two Capstone C65 biogas microturbines was paired with Unison Solutions gas conditioning equipment to utilize methane generated from the co-digestion of sludge, food scraps, and fats, oils, and grease (FOG).
• Waste-to-Energy Power Generation: Produces over 1,000 MWh of clean electricity annually on-site, supplying approximately 15% of the plant's total electrical needs and offsetting expensive local utility rates.
• Digester Thermal Integration: Captures 860,000 BTU/hr of exhaust waste heat to maintain optimum anaerobic digester temperatures, completely displacing natural gas boiler reliance.
• FOG Co-Digestion Optimization: Co-digesting FOG and food waste more than doubles biogas production while creating an additional municipal revenue stream via grease hauler tipping fees.
• Low-Maintenance Biogas Reliability: Utilizes air-bearing microturbines with a single moving part, delivering quiet, reliable, and clean power generation from variable biogas inputs.


The Results
• $100,000 Annual Savings: Significantly lowers treatment plant operating overhead through combined electricity cost avoidance and natural gas reduction.
• 40% Natural Gas Reduction: Drastically reduces fossil fuel consumption by substituting waste exhaust heat for boiler gas burn.
• EPA Green Power Member: Serves as a flagship municipal sustainability project, converting local waste into renewable energy.
• Long-Term Operational Support: Serviced continuously by Veristar since 2020, ensuring sustained equipment performance and reliable long-term uptime.