Energy from Biosolids & Other Residuals
Examples of facilities generating energy from the management of biosolids & other residuals in New England & eastern Canada...
While New England and eastern Canada have relatively few anaerobic digesters at municipal wastewater treatment facilities in comparison to other regions of the continent, this region does boast some pioneers, including:
Vermont's Cow Power - The Foster Farm in Middlebury, Vermont, started generating electricity from cow manure in the 1970s and continue to do so today. Learn more here. More recently, Central Vermont Public Services has been pursuing "Cow Power."
Massachusetts Water Resources Authority / Deer Island Wastewater Treatment Facility - MWRA, which provides water and wastewater treatment services for Boston and surrounding communities, has utilized biogas from its egg-shaped anaerobic digesters at the Deer Island Treatment Facility since the 1990s. This renewable energy supply saves MWRA nearly $18 million in energy costs per year. The use of biogas is only one of many energy projects at MWRA; see further details here.
Essex Junction (VT) Wastewater Treatment Facility - This small wastewater treatment facility has been a pioneer in successful combined heat and power (CHP) from biogas at a small wastewater treatment facility. Learn more from this Northeast Clean Energy Application Center fact sheet.
Nashua, NH Wastewater Treatment Facility - Nashua's single egg-shaped digester with a combined heat & power (CHP) system went online in 2000. An engine generator uses the biogas to produce electricity for the facility and heat for the digestion process and to warm some of the facility's buildings.
Greater Lawrence (MA) Sanitary Treatment District / NEFCO Biosolids Facility - GLSD, which provides wastewater treatment for Lawrence, MA and several surrounding communities, installed anaerobic digesters in the 2000s. At the same time, a biosolids heat-drying facility was built; it uses the biogas to heat-dry biosolids to make fertilizer marketed by NEFCO and other vendors throughout New England and beyond. Learn more from this Northeast Residuals & Biosolids Conference presentation.
"The Five Farms Project" - The first of five planned on-farm anaerobic digesters in Massachusetts went online in Rutland in spring of 2011. It provides improved stabilization and management of the Jordan Farm's dairy manure, as well as source-separated organics. The project has been hailed by Governor Duval Patrick and others promoting renewable energy and greenhouse gas reductions. See NECN news coverage. Learn more from this Northeast Residuals & Biosolids Conference presentation.
Sainte-Hyancinthe (QC) Wastewater Treatment Facility - This municipal wastewater treatment facility in central Quebec began operations of the first of three planned anaerobic digesters in 2010, utilizing municipal wastewater solids to produce biogas which is then used to heat-dry the biosolids for use as fertilizer on area farms and provide heat for the digestion process. A BioCycle article provides details.
In 2011, the Massachusetts Department of Environmental Protection published a report on "Tapping the Energy Potential of Municipal Wastewater Treatment."
U. S. EPA hosts the Combined Heat & Power Partnership, which provides resources regarding the potential for renewable energy from biogas.
Recovering Energy from Thermal Processing of Biosolids and Residuals
Most of the wastewater solids produced in southern New England are incinerated. Most of these system have long included use of some of the waste heat for building heat. Some facilities are now installing advanced energy recovery systems, including electrical generators.
Greater New Haven (CT) Water Pollution Control Authority operates a steam turbine to generate electricity from the waste heat at its wastewater solids incinerator. Start-up testing in fall of 2009 demonstrated the equipment will generate ~400 kW at a feed rate of 30 dry tons of solids. Fifty dry tons produces 600 KW. Learn more from this Northeast Residuals & Biosolids Conference presentation.
In the late 2000s, Stamford (CT) Water Pollution Control Authority developed and piloted a downdraft gasification system using heat-dried biosolids from its wastewater treatment facility to produce a synthetic renewable gas fuel. With significant funding from the U. S. Dept. of Energy, the pilot project demonstrated the concept, but local funding was never approved for construction of the planned full-scale facility. Learn more at the project's legacy website.
Recovering Energy from Composting Biosolids and Residuals
The Greater Monction Sewerage Commission composting facility was designed and built with heat recovery piping embedded in the concrete beneath the active, fabric-covered, composting piles. The captured heat is used to heat interior work spaces and de-ice portions of the composting operations.
The Hawk Ridge Composting Facility in Unity, Maine, owned and operated by New England Organics, built a new office building in 2011; it and a maintenance shop are heated by process water from the composting operation.