What is underground coal gasification?
Underground coal gasification (UCG) is an unconventional technique for extracting gas that does not involve fracking (hydraulic fracturing). Instead, oxygen is pumped from an onshore facility into underground coal seams offshore. The coal seams are ignited, producing synthetic gas, also known as 'syngas', which is pumped back to the surface onshore.
In the UK there are several UCG projects still at the exploration phase.