Tony Lodge: A brand new role for coal

Scotlands last deep coal mine closed at Longannet in 2002. Picture: Ian Rutherford

Not very long ago the Fife, Lothian, Lanarkshire and Ayrshire coalfields were producing high grade coal for power stations and Scottish industry. Colliery winding gear was a symbol of Scotland’s rich mineral resources. The quest for coal and mining’s subsequent and troubled decline has left its mark, a deep social and industrial legacy stretching across many generations.

The closure in 2002 of Scotland’s last deep mine, Longannet, on the north side of the Firth of Forth, was a watershed as access to deep coal seams finished. Coupled with the more recent troubles at opencast operator, Scottish Coal, these events illustrate the slow but sure decline of a once mighty industry which today faces a perfect storm of declining markets and ever tightening pollution rules.

A series of well documented developments fatally damaged the mining industry. These included the threat from cheap coal imports and alternative energy sources like atomic power and gas. In reality it was the need for coal mining to face market forces and try to compete economically, without government subsidy, which forced its contraction.

But whilst traditional intensive deep mining in the UK will soon have reached its natural end, as seams run thin and new coal faces cannot be financed at the remaining English deep pits, there is a new dawn for coal which is only just emerging to policy-makers and a wider audience. It represents huge potential for Scotland; with this new technology, not one tonne of the black stuff needs reach the surface. First, some fascinating facts which will raise eyebrows. Vast tracts of the UK seabed and coastal waters are floored by deep coal seams. When the oil pioneers of the 1960s and 70s were prospecting for “the prize”, they were consistently surprised to see their drilling gear initially going through thick coal seams. It is estimated that billions of tonnes of high quality coal lies within UK territorial waters.

But this coal has typicallly been seen as “stranded”. It was not recoverable through traditional mining techniques, even though some Durham pits did mine the seams under the sea, though in difficult conditions. Similarly, vast coal reserves exist onshore but the seams were either uneconomic to reach or the conditions made mining impossible.

The frustration of stranded coal now looks set to change. A new technique called deep underground coal gasification (UCG) can allow the UK to exploit these vast coal reserves and produce bountiful energy, without any of the environmental impacts associated with traditional mining.

Deep UCG is a method of burning coal in situ (very deep in the seam) to produce a synthetic gas, known as syngas. This can be used to generate electricity or supply industry onshore. First, two boreholes are drilled into underground coal seams, either onshore or offshore. A pressurised oxidant is pumped into one borehole which is ignited, partially burning the coal and emitting syngas, a mixture of hydrogen, methane, carbon monoxide and carbon dioxide, which travels up the second well to be processed.

Repeated attempts in the UK at trialling a system suffered a lack of leadership, first by the old National Coal Board, which refused to offer decent sites for European trials in the early 1990s. In terms of seismic shocks or small earthquakes – a major concern for some who follow the shale gas debate – deep UCG should be no more susceptible than conventional underground mining. Importantly, the process can leave pillars of unaffected coal to support the projects without any subsidence, which was often a key failing of conventional coal extraction across the Scottish coalfields.

Slowly the cogs are turning to help deliver gas from stranded underground coal reserves. The UK government has awarded 18 licences for UCG trials in the UK. Long-standing mining entrepreneur, Algy Cluff, risks being crowned the new “King Coal” if his plans to develop deep UCG in the UK are fully developed; it is a serious project. His Cluff Natural Resources has just been awarded an important 3,600 hectare UCG prospect licence in the Firth of Forth, near Kincardine. This area has been described as ideal for UCG by Heriot-Watt University, mainly because of its large and high quality coal resources and proximity to local gas-hungry customers.

Importantly, unlike shale gas fracking, UCG does not possess any of the same characteristics in that no injection of chemicals or fracturing of the underground rock takes place. Also, where shale “frackers” are effectively prospecting, UCG developers have a vital advantage: they know where the coal is and where the most appropriate coal seams are situated as a result of Coal Board surveys carried out years ago. UCG must now receive the same tax break as that given to shale.

Scotland is to become more dependent on gas for the generation of its electricity in future. As the last Scottish nuclear plants close at Hunterston (2016) and Torness (2023), and older coal plants like Cockenzie are replaced by gas plants, it is clear that Scottish energy policy will become based around more renewables but with gas acting as the main baseload generator of electricity. Scotland’s biggest power plant at Longannet will probably be replaced by gas when it closes; it is now 40 years old. So gas looks set to replace traditional nuclear and coal plants.

It is therefore critical that Scotland develops as varied a gas supply chain as possible to mitigate any overdependence on foreign gas and erratic import prices. Cheaper fuels and, because of new carbon taxes, cleaner fuels, reduce fuel poverty and make energy intensive industry more competitive.

One hundred years since Scotland’s coal production peaked at 43 million tonnes, new technology looks set to transform the way we use and view this valuable resource. Political leaders want us to use more gas to keep the lights on; it now needs to learn how coal, and Scottish coal, has a vital role to play in its plans.

• Tony Lodge is a research fellow at the Centre for Policy Studies (CPS). He is author of Clean Coal – A Clean, Secure and Affordable Alternative published by the CPS