When we think of renewable energy, we typically think of wind, solar, and hydroelectric energy sources. Should energy from landfill gas be added to this list? Currently, 36 states consider landfill gas to be a renewable energy source, and offer some financial incentive for its capture and use.
Incentives for landfill-gas-to-energy (LFGTE) projects are one of the most complex issues in solid waste management in the US (for a list of the posts we’ve written on this subject to date, look here; and for a summary of the issue, look here).
Does it make sense to call landfill gas a ‘renewable’ energy resource? While doing so might reduce the release of methane into the atmosphere (a good thing), it may also incentivize the continued placement of organic materials in landfills, thus discouraging composting or anaerobic digestion efforts.
What does it mean for landfill gas to be classified as ‘a renewable energy resource’ and who would benefit from this?
While there are still no federal regulations governing the amount of energy in the US that must come from renewable sources, 29 states, plus DC and 2 territories, have Renewable Portfolio Standards (RPS). Eight additional states have set Renewable Portfolio Goals (non-mandatory). Here’s a nice table (from 2004) describing most of them.
Most of these states’ goals say something like, “by 2020 30% of energy produced in this state will come from a renewable energy source.” Typically to qualify as producing renewable energy, utilities must obtain renewable energy credits (RECs**) from other eligible renewable resources. A REC (Renewable Energy Credit) can be purchased from someone who produces renewable energy (thus, for example, a coal power plant could purchase RECs equivalent to 30% of its energy output from a solar energy plant to meet a state-wide RPS).
By calling landfill gas a renewable energy resource, landfills have a financial incentive to construct landfill-gas-to-energy projects because they can sell their RECs to other utilities.
So should we consider landfill gas ‘renewable’? Collecting LFG for energy, rather than letting it seep out of landfills into the atmosphere reduces the release of greenhouse gases from landfills. However, calling LFG ‘renewable’ suggests that garbage ‘naturally’ replenishes itself… and while this does seem to happen in practice, the production of trash itself relies on an enormous amount of energy input (the energy that went into making, growing, and transporting all those products we throw away). You have to keep adding more trash to get more landfill gas. Another drawback of including LFG in the list of RECs, is that it may slow the development of technology to better utilize other sustainable energy sources. Energy from LFG is currently cheaper to produce than from solar or wind sources, and so long as both LFG and solar/wind can meet REC, there’s less incentive to improve solar or wind technologies.
A Catch-22. What do you think we should do?