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Introduction
In 2003, only 3 percent of electrical power in Pennsylvania came from renewable sources. The following year, legislators in the state hoped to increase that percentage by enacting the Alternative Energy Portfolio Standard (AEPS). While it may not be renewable in the eyes of Pennsylvania, coal mine methane (CMM) was included in AEPS. There are some drawbacks to CMM, but there are certainly positives as well. Capturing and using CMM can provide additional revenue to mine operators when the gas is sold. It can also provide an alternative fuel for vehicles. This Fact File explains what CMM is, how AEPS works, and the subsequent Alternative Energy Credits (AEC) that resulted from it all.
Background
Methane is a naturally occurring hydrocarbon gas that can exist underground. It is lighter than air, colorless, odorless, and flammable. Coal mine methane (CMM) refers to the methane released from coal and the surrounding rock strata from mining actions. This methane in mines poses a safety risk due to its explosiveness when mixed with air. Underground coal mines account for most methane emissions from coal mining in the United States and worldwide. Less substantial sources of CMM come from surface mines and post-mining actions, like storage and transportation.
Before using CMM, it must be captured by drainage and/or ventilation systems and transported to the surface. In the United States, most recovered CMM is sold to natural gas pipeline systems. Common uses of CMM around the globe include:
- Power generation
- District heating
- Boiler fuel
- Sales to natural gas pipeline systems
CMM can also be used for coal drying, a heat source for mine ventilation air, vehicle fuel, manufacturing feedstock, or a fuel source for fuel cells.
Even though Pennsylvania classifies CMM as an alternative energy, there are still many environmental risks associated with this energy source. Methane is the second most significant greenhouse gas following carbon dioxide. It is 28–36 times more powerful than carbon dioxide on a mass basis over a 100-year period.
Coal mine methane and alternative energy portfolio standards
Pennsylvania was the first state to define CMM as an alternative energy fuel in its AEPS. This was signed into law via Act 213 on November 30, 2004 by Governor Ed Rendell. The AEPS does not distinguish between renewable and alternative energy resources. All the sources are classified as alternative energy. For reference, renewable energy resources include sources like solar-electric, solar thermal energy, wind power, hydropower, geothermal energy, fuel cells, and biomass energy and biologically derived fuels. But alternative energy source classification differs from state to state. Eligible technologies include demand-side management, waste coal, CMM, and coal gasification.
The AEPS requires each electric distribution company and electric generation supplier that sells electricity to clients in Pennsylvania to supply 18 percent of its electricity from alternative energy resources by May 2021. Of that total percentage, 8 percent percent of the electricity must be from Tier I energy sources. This tier includes electric generation resources such as wind, biomass, coal mine methane, low-head hydro, and a special subcategory for solar photovoltaic generation. The other 10 percent needs to be from Tier II sources. This tier includes generation from resources like waste coal, distributed generation, and a subcategory for conservation that includes demand side management, demand response, energy efficiency, large-scale hydro, and coal gasification.
Pennsylvania Alternative Energy Credits
Act 213 established a commodity unique to Pennsylvania called an Alternative Energy Credit (AEC). Basically, an AEC is the proof that a certain amount of energy has been saved or that a certain amount of alternative energy has been produced. An AEC is defined as being equal to 1,000 kWh (kilo-watt hours). When a qualified Tier I or II facility has produced 1,000 kWh, the owner of the rights to the credits or their designee must post the mandatory information into a digital information tracking system called the Generation Attribute Tracking System (GATS). GATS goes on to assign a certificate number for every AEC. The certificate number is used to track present and upcoming ownership.
Applicable laws & regulations
Act No. 213 of 2004 – Alternative Energy Portfolio Standards Act – Enactment
Related definitions
“Biomass” means any organic material that has stored sunlight in the form of chemical energy, like plants, agricultural crops or residues, municipal wastes, and algae.
“Fuel cells” mean any electrochemical device that changes chemical energy in a hydrogen-rich fuel directly into electricity, heat, and water without combustion.
“Gasification” means a technological process that can convert any carbon-based raw material like coal into fuel gas, also known as synthesis gas.
“Greenhouse Gas” means a unit of greenhouse gas, including carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, and nitrogen trifluoride.
Keys to remember
It is important to note that while Pennsylvania classifies CMM as a Tier I fuel, this does NOT include commercially developed coal bed methane (CBM). CBM refers to methane that is found in and extracted from coal seams. It is formed during the coalification process. This is the conversion of organic plant material into coal. CBM is broadly thought of as an “unconventional” source of natural gas. Although CMM is like CBM in that it is a subset of the methane found in coal seams, it refers specifically to the methane found within mining areas (e.g., within a mining plan). CBM on the other hand, refers to methane in coal seams that will never be mined. Because CMM would be released through mining actions, the recovery and use of CMM are considered emissions avoidance.
Real world example
The U.S. Department of Energy (DOE) is always looking for ways to reduce methane emissions in the oil, gas, and coal industries. On December 2, 2021, the DOE announced that $4,366,015 would be awarded to a company based out of Wayne, Pennsylvania to develop technology to reduce methane from coal mine shafts. Their technology uses a noble metal catalyst to combust the dilute methane in coal mine ventilation systems. This was one of 12 projects awarded funding to help in methane reduction. The future of alternative and renewable technology is changing rapidly, always with the aim of improving not just emissions from methane but all emissions.