Switch to Direct Thermal
When landfill gas (LFG) volume is sufficient for a project, but electricity generation is no longer feasible, switching to a direct-use project may be a viable option if there is an onsite or nearby thermal need.
Examples
The Jackson County Green Energy Park in North Carolina puts 40 cubic feet per minute (cfm) of LFG to use in various ways—greenhouses, blacksmithing, glassblowing, a metal foundry and more. Since 2006, the Park has had a significant impact on the local economy and offered students, professionals and tourists the opportunity to see LFG being used as a fuel.3
In 2009, Crow Wing County, Minnesota, began combusting 30 cfm of LFG in a boiler to heat a maintenance building via an in-floor heating system. This onsite use of LFG reduced the facility’s use of natural gas by 70 percent.4
J.J. Brunner Landfill in Pennsylvania has used its LFG to evaporate leachate on site since 2005. For 10 years, the site used a submerged combustion evaporator, but switched in late 2015 to a concentrator technology that uses waste heat from the flare. The new system provides more than 95 percent reduction in leachate volume.5
Criteria:
- Customer within five miles of landfill has a consistent thermal demand.
- Customer is willing to pay green gas premium for the project to be economically feasible given low fossil natural gas prices.
Pros:
- An onsite demand for heat or hot water pairs well with an LFG supply.
- A direct thermal project can often use a lower LFG flow rate than a typical electricity project.
- LFG does not generally require any additional treatment beyond what was required for an electricity project.
Cons:
- Since fossil natural gas prices are low, the economics of this project type may be a challenge unless the renewable aspect of LFG can intrigue potential customers.
- If LFG is used on site, the combustion device may need to be retrofitted.
Economic Considerations:
- Cost ranges for a 1,000 or 3,000 standard cubic foot per minute (scfm) project:
- Retrofit costs for a boiler can range from $120,000 to $516,000, depending on the level of retrofit needed.2
More Information:
- LFG Energy Project Development Handbook Chapter 3. Project Technology Options, EPA LMOP
- Adapting Boilers to Utilize Landfill Gas, EPA LMOP
References
1 U.S. EPA. Landfill Gas Energy Project Development Handbook. Chapter 4. Project Economics and Financing. July 2021. https://www.epa.gov/lmop/landfill-gas-energy-project-development-handbook.
2 U.S. EPA. Landfill Gas Energy Project Development Handbook. Chapter 3. Project Technology Options. July 2021. https://www.epa.gov/lmop/landfill-gas-energy-project-development-handbook.
3 U.S. EPA. LMOP Project Profile: Jackson County NC Green Energy Park. https://www.epa.gov/lmop/landfill-gas-energy-project-data#jackson.
4 U.S. EPA. LMOP Project Profile: Crow Wing County Small Onsite Boiler Project. https://www.epa.gov/lmop/landfill-gas-energy-project-data#crow.
5 U.S. EPA. LMOP Project Profile: J.J. Brunner, PA Leachate Evaporation. https://www.epa.gov/lmop/landfill-gas-energy-project-data#brunner.