By Drs. Robert & Sonia Vogl
President and Vice President, Illinois Renewable Energy Association
Some methods of keeping more energy dollars in our communities include local foods, energy efficiency and renewable energy. Sewage treatment plants use a substantial amount of energy operating their facilities, so they provide excellent opportunities for improving energy efficiency and installing renewable energy systems. Making those improvements can also increase the security of the energy supply for these vital services. Using renewable energy sources can help the utilities meet their renewable portfolio standards.
The specific amount of energy used at a wastewater treatment facility will vary by the size of the plant and the daily average of wastewater being treated. Also important are the characteristics of the incoming water from households, businesses and industries.
On average, it is estimated that 30 percent of the overall operating cost of a treatment plant is attributable to energy costs. In turn, 50 percent of the energy consumed at the plant is used in the aeration process, where biological treatment breaks down organic wastes.
At the West Water Reclamation Facility in Kane County, high-efficiency turbo blowers were installed to cut electrical consumption and reduce routine maintenance. Energy savings of 231,500 kWh/year amount to a cost savings of $18,520 per year.
Modification of the activated sludge treatment facility reduced the amount of air required in the aeration tanks, producing an additional savings of 144,900 kWh/year and an additional $11,592 per year in operating costs.
A $45,168 grant from the Illinois Clean Energy Community Foundation helped fund the Kane County project.
The Illinois Department of Commerce and Economic Opportunity is encouraging facilities to install similar energy-efficient equipment by utilizing reimbursement funds in combination with the Illinois Environmental Protection Agency State Revolving Fund and funds from the Illinois Clean Energy Community Foundation. For additional program information, go to http://www.illinoisbiz.biz/dceo/Bureau/Energy_Recycling/.
In Galena, Ill., the wastewater treatment plant for roughly 3,000 people has been equipped with a 368 kW solar array. It is estimated to provide 480,000 kWh of electricity and avoid 920,000 pounds of greenhouse gas emissions over the 40-year life of the project.
A $908,000 grant from the Illinois Clean Energy Foundation funded 60 percent of the project’s cost. Local officials estimate their share of the cost of the project should be recouped in about seven years. The $120,000 per year electrical costs of operating the water reclamation plant are expected to be reduced to about $50,000 to $60,000 per year. The solar installation will provide about half of the electrical needs of the facility.
The project involved cooperation with Galena officials, Eagle Point Solar and Jo-Carroll Energy, a regional electric co-operative.
A similar project is under way in Rochelle, Ill., with an initial installation of 26 kWh system at the water reclamation district with the potential of adding additional capacity in the future. Funds from the Clean Energy Community Foundation will facilitate the project’s development.
Targeting sewage treatment plants for energy efficiency and PV installations has local financial and environmental benefits. Another potential benefit is that by combining efficiency, solar electricity and co-generation units using methane produced from human waste along with supplemental natural gas supplies, sewage treatment plants could operate as microgrids, increasing local energy security.
Drs. Robert and Sonia Vogl are founders and officers of the Illinois Renewable Energy Association (IREA) and coordinate the annual Renewable Energy and Sustainable Lifestyle Fair. E-mail email@example.com.
From the March 26-April 1, 2014, issue