Natural gas has the potential to reduce carbon emissions
Emissions from shale gas lower than coal and imported natural gas from outside Europe
Flaring and venting are only used when absolutely necessary
The use of natural gas extracted from shale reservoirs has significant potential to reduce the UK’s overall carbon emissions.
Recent reductions in the UK’s carbon emissions have been largely due to the displacement of coal-based power generation in favour of natural gas. In 2011, this accounted for 35% of the UK’s primary energy consumption compared to just 16% for coal.
However, plenty of scope still remains to reduce the UK’s reliance on coal. DECC figures show that in 2012, coal power overtook gas to become the biggest single source of UK electricity generation.
How does shale gas compare to other fuels?
Not only does the burning of natural gas to produce energy release around half the carbon emissions of coal, but a highly regulated UK onshore industry can ensure that shale gas extraction has the potential to produce lower emissions than natural gas imported from outside Europe.
While shale gas resources in the UK can be hooked up to the National Grid soon after production, the long distances involved in transporting gas from outside Europe increase the opportunity for additional emissions.
What are fugitive emissions?
Fugitive emissions are gases that can escape into the atmosphere during industrial production processes and during transport. These emissions can also occur in numerous other industrial practices, such as mining and at landfill sites.
Fugitive Emissions in Hydraulic Fracturing (Fracking)
Some commentators believe that the release of methane during the hydraulic fracturing process could counteract the benefits derived from lower carbon dioxide emissions from natural gas.
However, there is no scientific consensus on this issue. A report by AEA Technology produced for the European Commission in July 2012 concluded that “the majority of studies suggest that emissions from shale gas are lower than coal…” suggesting that greenhouse gas emissions would be reduced in the UK by replacing coal with gas based energy generation.
Flaring and Venting
- Flaring is the controlled burning of natural gas.
- Venting is the controlled release of natural gas without burning.
Both flaring and venting release greenhouse gases, sulphur dioxide (SO2) and methane into the atmosphere.
The oil and gas industry takes great care to avoid flaring and venting natural gas wherever possible.
Not only are these harmful to the environment, but natural gas is valuable both economically and as an energy resource. Therefore, it is in the best interests of operators to be as efficient as possible so that they can deliver as much natural gas as possible to their customers.
Flaring is primarily used as a safety mechanism at oil and gas facilities to remove gas safely prior to plant maintenance, or if there is a problem with the facility. In some cases, very small amounts of natural gas are flared if it is not economically viable to build a pipeline or other infrastructure to make use of it.
What has happened in the United States?
The recent experience in the USA shows how shale gas can help countries like the UK meet their carbon demands:
- Between 2005 and 2010, carbon emissions in the USA fell by 403 million tonnes, at a time when electricity production from natural gas rose by 62%
- This coincided with a reduction in the USA’s reliance on coal for its energy needs, with electricity net generation from coal falling by 25% between 2007 and 2012
- This helped the USA to reduce its carbon emissions to a 20 year low in the first quarter of 2012, achieving approximately 70% of the CO₂ emission reductions targeted under the Kyoto Agreement.
Natural gas is also being used as a transport fuel, now powering 19% of public transport buses, helping to reduce carbon emissions and improve air quality still further.