The EPA has now gathered input to reduce emissions from the nation’s gas turbine power plants. The initiative zeroes in on enhancing technology at combustion sites —integrating battery storage, solar power, and upgrading equipment efficiency through retrofits. However, the elephant in the room is the crucial need to address the gas supply itself.
Beyond technology improvements at the power plants, there are three ways to significantly reduce CO2e emissions across the value chain of a gas-turbine power plant: 1) using biogas, also referred to as RNG (renewable natural gas); 2) adopting certified natural gas; and 3) utilizing CCUS (carbon capture, utilization and storage) technologies.
Biogas is natural gas produced by anaerobically digesting organic matter, such as animal or municipal solid waste in landfills. It is considered carbon neutral, and in some cases, carbon net negative, as it involves the combustion of methane that would otherwise have been released into the atmosphere. However, using biogas has downsides. Its gathering and transmission are less efficient than traditional natural gas, and it is not nearly as plentiful. As a result, the price is much higher – as much as $20 more per MMBtu than fossil gas.
Certified natural gas is the same as natural gas but is produced according to strict protocols, with verified emission rates and practices audited by third-party verifiers. As of writing this, over 30 percent of gas produced in the US is certified to be 80 – 95 percent lower in methane intensity than the national average. Because repairing leaks can be relatively affordable, and gas is saved (i.e., it doesn’t leak out into the atmosphere) certified natural gas can be very cost-effective. At production levels of 22+ bcf per day, certified gas is plentiful, and the premium is just a few cents per MMBtu.
Carbon capture, utilization, and storage (CCUS) consist of a group of technologies that can be implemented at the point of combustion to capture CO2 combustion emissions before they are released into the atmosphere. CCUS technologies are in various stages of development and field operation. The table below summarizes the pros, cons, and relative costs of each concept:
| Pathway | Pros | Cons | Relative Costs |
| RNG/Biogas | – Carbon neutral – Non-fossil fuel | – Difficult to scale – Expensive | – Very high added operating cost |
| Certified gas | – Plentiful – Lower methane intensity – Infrastructure in place – Affordable | – Not carbon neutral | – Very low added operating cost – Potentially eligible for IRA tax credits (45V) (regulations still under review) |
| CCUS | – Can reduce or eliminate carbon emissions occurring from combustion | – High capital cost – Requires suitable geology or pipelines for storage – May incur power penalty – Some types of CCUS technologies still in design or pilot phases | – Potentially eligible for tax credits (45Q) (regulations still under review) or sell captured CO2 |
The EPA must prioritize the consideration of upstream emissions and the impact of fuel choices in its strategy for the U.S. gas turbine power plant fleet. The selection of fuels is pivotal in achieving the dual objectives of reducing greenhouse gas emissions—particularly upstream methane leaks—and ensuring low-cost energy solutions for ratepayers. Despite existing limitations on requiring certified gas, the EPA should lead the charge in raising awareness about the critical issue of upstream methane leaks and advocate for the adoption of accessible and cost-effective alternatives that can effectively tackle these challenges. By doing so, the EPA can drive meaningful progress in our national efforts to combat climate change while safeguarding affordable energy for all.