The environmental and public health case for British onshore shale gas
The arguments in favour of exploring Britain’s apparently vast shale gas resources have so far centred largely on the economic benefits: jobs, tax revenues and increased energy security. What we haven’t heard much about are the environmental or public health advantages. Here’s a brief summary.
Sour gas from Qatar
Qatari gas, which in 2013 accounted for 92% of natural gas imported in liquefied form, and 18% of total gas imports (GWh), is high in hydrogen sulphide (H2S), which means it needs more cleaning and that uses energy and chemicals – both there and again when it arrives here. H2S is a highly toxic gas too, and so extra care needs to be taken in handling sour gas to avoid dangerous leaks.
Liquefaction of gas
Turning natural gas into a liquid state for transport purposes is a very energy and CO2 intensive process. And, of course, it has to be re-gasified when it gets to its destination, consuming even more energy and creating more polluting emissions.
Carbon intensity compared to LNG
In their 2013 report, the former DECC Chief Scientist, Sir David McKay, and Timothy Stone concluded that carbon footprint of onshore shale gas would likely be in the range 200 – 253 g CO2e per kWh of chemical energy, which makes shale gas’s overall carbon footprint lower than the carbon footprint of Liquefied Natural Gas (233 – 270g CO2e/kWh(th)).
It is believed that as much as 6% of gas imported via pipeline from Europe is lost to atmosphere during transmission. Unabated methane is a much more potent Greenhouse Gas than CO2. Gas produced onshore in the UK, and closer to the customer, will help to avoid some of these losses.
Depleted shale gas wells could be repurposed into deep geothermal wells, with shale gas extraction acting as an enabler of renewables as this partnership shows.
Co-location of biogas plants
By sharing pipeline access and other infrastructure, shale gas operations could help to reduce the cost of AD deployment, increasing the availability of biogas for injection into the gas grid and again acting as an enabler of renewables.
Substituting for coal in electricity generation
Burning coal to generate electricity creates emissions of nitrogen and sulphur oxides (linked to acid rain and breathing difficulties); the release of gaseous mercury (a known neurotoxin) and naturally occurring radioactive material; harmful particulate emissions (linked to premature mortality rates); and huge amounts of CO2 (a contributor to climate change). Right now, up to 50% of UK electricity is supplied by coal-fired generation, and so substituting more natural gas would make for climate and public health improvements.
Despite the public angst in some quarters, the science is clear: domestically produced onshore shale gas, as a partial replacement for imported gas and used as a substitute for coal in electricity generation, means cleaner air and better hopes for the climate.