Columbus, Ohio, Increases Sustainability While Saving Energy Costs

The City of Columbus, OH, designs a state-of-the-art energy system to convert excess biogas into renewable energy

8-10 MT eCO2/year

reduction in greenhouse gas emissions (equivalent of 1,600-2,000 cars removed from the road)

$1.0-1.5M

per year in energy cost savings

The Columbus Green Community Plan is a 15-year strategic plan designed to make the City of Columbus, OH, a more sustainable, greener place to live. The plan contains objectives that include a focus on climate change, energy, the built environment and community engagement. The city hired Arcadis to deliver a sustainable power system at the Jackson Pike Wastewater Treatment Plant (JPWWTP) to help meet these objectives.

Currently, the city operates anaerobic digestion at JPWWTP, a sustainable process that breaks down biodegradable waste to produce a methane-rich biogas. When the digesters produce more biogas than the plant can recycle, excess biogas is flared into the atmosphere.

In anticipation of upcoming changes to EPA regulations, the city chose to discontinue incineration of its biosolids. The change resulted in less utilization of its available biogas and consequently more flaring. The city hired Arcadis to design and install a cogeneration system that will convert the excess biogas into electricity and heat – renewable energy – that powers and heats the plant, an environmentally-friendly alternative to using coal or natural gas.

A combined heat and power (CHP) generator, integrated into the electrical system, will burn the excess biogas in a gas engine. The process ultimately minimizes the need for flaring and reduces the plant’s impact on the environment. Surplus heat captured during the cogeneration process will be recycled and used to meet the plant’s process and building heating needs. Improvements made at the JPWWTP are slated to help the city achieve many of its energy goals. The city’s use of renewable energy represents a significant step forward in building a community with thriving social, environmental and economic structures.

“Using biogas to fuel the engines is significantly more efficient and environmentally friendly than using coal power or natural gas, and it will strengthen our city’s sustainability going forward,” said Todd Krenelka, Columbus Department of Public Utilities. “The city has a strong interest in fully using our resources, and this project meets multiple objectives within Columbus’ Green Memos.”

Preliminary investigations estimate the new system may save the city approximately $1.0-$1.5 million per year in energy costs. Additional benefits include a reduction in annual greenhouse gas emissions equivalent to 1,600-2,000 cars being removed from the road.

Example of a CHP engine installation at Cedar Creek Water Pollution Control Plant, Nassau County, Long Island, NY.

Outcomes

8-10 MT eCO2/year

reduction in greenhouse gas emissions (equivalent of 1,600-2,000 cars removed from the road)

$1.0-1.5M

per year in energy cost savings