Tony Lodge: As the last pitheads disappear, a new dawn emerges for coal

Along with the slag tips and 
associated surface buildings to 
process, wash and transport the coal from pithead to power station, it is fair to say that the quest for coal and mining’s subsequent decline has left its mark; a pockmarked landscape and a deep social legacy stretching across many generations.

The closure this month of the 100-year-old Maltby Colliery, near Rotherham, represents a watershed in the long decline of coal mining in the UK.

Though modernised at great expense by the National Coal Board in the 1980s, Maltby has succumbed to geological problems which have made it uneconomic.

The pit started producing coal in 1913, the very year that British coal output peaked at a staggering 287 million tonnes. In the year before the 1984 coal strike, deep-mined output had fallen to 90 million tones.

A series of well-documented developments undermined the industry, including 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. For years, all governments had written off the industry’s losses and forced the electricity generators to buy British-mined coal, when imports were often cheaper.

But while traditional intensive deep mining will soon have reached its natural end in the UK as seams run thin and new coal faces cannot be financed, there is a new dawn for coal which is only just emerging to policymakers and a wider audience.

First, some fascinating facts which will raise eyebrows; vast tracts of the UK seabed 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 going through coal first. It is estimated that billions of tonnes of high quality coal lie within UK territorial waters.

But this coal has traditionally been considered to be “stranded”. It was not recoverable through traditional mining techniques, even though some Durham pits did mine along the coast. Similarly, vast coal reserves exist onshore but the seams were either uneconomic to reach or the conditions made mining impossible.

But this looks set to change. A new technique called 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.

UCG is a method of burning coal in situ (in the seam) to produce a synthetic gas, known as syngas. This can be used to generate electricity or supply industry.

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 have been scotched, first by the old National Coal Board/British Coal, 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 – UCG should be no more susceptible than conventional underground mining. Importantly, the process can leave pillars of unaffected coal to support the projects without subsidence, which was often a key failing of conventional coal extraction in the UK.

It is important to realise that UCG differs from shale gas in many positive ways. Shale gas is another fossil fuel that has been much touted for its abundance, aided by a recently discovered method known as 
hydraulic fracturing, better known 
as “fracking”. This controversial technique works by injecting a high-pressure liquid into shale rocks, 
which creates new channels for gas extraction. But this causes problems which the companies themselves acknowledge. The fracking liquid contains chemicals and the process 
can release locked-up stresses in the rocks, which can cause small earthquakes.

Slowly the cogs are turning to help deliver gas from stranded underground coal reserves. The 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 UCG in the UK are fully realised; it is a serious project. His Cluff Natural Resources has just been awarded two licences covering 111 hectares of Carmarthenshire and the Dee Estuary, on the North Wales/Merseyside border and that could just be the start.

The UK has become one the most gas-dependent states in the world. It is therefore critical that it develops as varied a gas supply chain as possible. With a rising tax on carbon emissions 
it is also important to burn cleaner 
fuels in order to lessen the impact of that tax on companies and the consumer.

The gas extracted from the UCG process can be stripped of its pollutants to deliver a very clean energy source and, ironically, it could be those now abandoned gas and oil platforms which provide the basic infrastructure to kick-start a new coal to gas industry in the UK.

One hundred years since Britain’s coal production hit its peak and new technology looks set to transform the way we use and view this valuable resource. The Government wants to use more gas to keep the lights on; it now needs to learn how coal has a vital role to play in its plans.