Coal mine methane (CMM) or mine gas is the damaging greenhouse gas released from coal seams during and after mining operations. Methane is released into the atmosphere when coal is mined and continues to emit long after mining operations are abandoned. In the UK, there are over 1,000 disused coal mines and DEFRA research supports the industry view that these mines are responsible for substantial UK greenhouse gas emissions.
According to estimates in two DEFRA* reports on CMM emissions prepared by environmental consultants White Young Green in 2005, the largest abandoned coal mines in the UK emit over 60,000 tonnes of methane per year, equivalent to approximately 1.4 million tonnes of CO2. The consultants modelled future mine methane emissions and showed that these will continue beyond 2050. They concluded that “It is clear that recent closures and closures in the near future are likely to make significant step increases in the total emissions for the next 5 to 10 years”.
The cumulative total emissions which could be captured during this time-frame is estimated at nearly 30 million tonnes of CO2 equivalent. This means that 1.3 million tonnes of pure methane will emit to the atmosphere unless energy capture schemes are installed on all the abandoned mine sites reported by DEFRA. If all this methane were converted into electricity, the cumulative total to 2050 works out at 45,000 GWh, equivalent to the output of a small gas fired power station.
Alkane has six mine gas capture plants operating in the UK and one in Germany. The company’s inventory of UK licences and mines is currently being reviewed in the light of the recent higher electricity prices, coal bed methane (CBM) potential and to complete plans for a 5 year drilling and development programme. In addition, the company is planning to increase output capacity at existing sites where gas reserves are proven and these additional developments will be completed as soon as practicable.
The following Alkane Energy UK Limited sites with an installed capacity of 16.61MW are currently in operation saving the equivalent of around 560,000 tonnes of carbon dioxide per year.
| Site | Location | Capacity (MW) | Max CO2 mitigation (tonnes) |
|---|---|---|---|
| Bevercotes | Nottinghamshire (UK) | 4.05 | 138,155 |
| Joarin | Gelsenkirchen (DE) | 1.0 | 34,112 |
| Mansfield | Nottinghamshire (UK) | 3.7 | 126,216 |
| Sherwood | Nottinghamshire (UK) | 0.66 | 20,467 |
| Warsop | Nottinghamshire (UK) | 1.35 | 46,052 |
| Wheldale | West Yorkshire (UK) | 4.5 | 153,054 |
| Whitwell | Derbyshire (UK) | 1.35 | 46,052 |
| Total | 16.61 | 564,108 |
Converting this into emissions saved using the British Airways carbon savings calculator it is equivalent to a reduction in emissions from 3 return flights a day from Heathrow to New York or 115,000 cars off the road for a year.
- Projected Methane Emissions from Abandoned Coal Mines in the UK - White Young Green for DEFRA Ref: Report/E005832\SK\Final\Dec 2005\V2
- Development of a Methodology for Estimating Methane Emissions from Abandoned Coal Mines in the UK – WYG for DEFRA Ref: Report/D5559/Sk/May 2005/Emissions/V3
