Why, you may well ask, is an item on the coal-fired power generation in the UK accompanied by a picture (left) of JMW Turner’s famous 1838 oil painting ‘The Fighting Temeraire tugged to her last Berth to be broken up’?  Well, for an explanation you will have to read this item through to its end…!

Between 22:05 on the evening of Thursday 20th April and 23:00 the following evening, the UK experienced its first full day in 135 years in which its electricity generation ‘mix’ didn’t involve combusting a single tonne of coal.  A National Grid spokesperson described this a “a watershed moment in how our energy system is changing”, although did add that while the UK transitions to a low-carbon energy system, coal will remain an important source of energy.

Coal has been a part of the UK electricity generation mix since 1882, when the world’s first public coal-fired power station was opened at Holborn Viaduct in London (this a year after Godalming in the UK became the first town to provide a true public electricity supply scheme – in that case based on hydroelectric power).  However, the Holborn Viaduct steam station, like the Godalming hydro station, could not compete on price with town gas for lighting, and closed in two years later.  However, despite this faltering start, coal soon became the fuel of choice for generation, accounting for virtually 100% of UK electricity generation up until the mid-1920s, and only falling below 90% from 1965 with the early nuclear power plants coming on-line.  Coal-fired generation maintained its lead until natural gas use briefly exceeded coal use in 1999.  Subsequently, the share of electricity generation from coal and gas has tended to fluctuate under the influence of the relative prices of these fuels and the availability of other sources such as nuclear, but coal had declined to a 22% share in 2015 (with gas at 30%, renewables approaching 25% and nuclear at 21%), and fell to just 9% of the mix in 2016 (the year in which the UK government announced its intention to close the remaining unabated coal-fired power stations by 2025).  This situation seems very far removed from the late-1970s/early-1980s, when UK electricity generation sourced from coal reached its peak, with nearly 250TWh of electricity being produced annually from coal-fired stations.

The “watershed moment” on 21st April of over 24 hour’s electricity generation without coal, was clearly the result of a number of factors – lower electricity demand (normal on a Friday in the UK, and in a week following the Easter holidays) and a large amount of wind and nuclear power – but these moments will clearly become more common and then the norm over the coming years.  By the afternoon of 21st April, CCGTs were supplying 47% of the country’s electricity, wind turbines 18%, nuclear power plants 18%, solar PV generation 10% and biomass-fired stations some 6%.
It was interesting to read the press coverage of this event, with many commentators celebrating it.  I must say that as an ex-(coal) mining engineer with a career involved in clean coal technologies and carbon capture and storage, I found this a sobering moment.  Yes, the landmark helped to push UK carbon emissions down to some of their lowest levels since the late 1800s, but I was left wondering what might have been if the UK had pressed forward with a new generation of supercritical coal-fired plants, implementing CCS, and continuing to undertake collaborative RD&D on ‘700degC’ ultra-supercritical steam conditions – at least we might then have a clear roadmap for developing CCS technology for all that gas-fired power generation…

And so back to ‘The Fighting Temeraire’.  Art experts and historians alike have written much about explored the symbolism intended by Turner in his famous painting.  The obsolescence of sail power (conveyed by the sunset behind HMS Temeraire as she is towed towards her final berth in Rotherhithe’s breaking yards, and the becalmed gaff-rigged river boat and the square-rigger and other sailing ships beyond) and the commencement of the new industrial era (represented by the steady progress of the paddle-wheel steam tug and the gleaming sliver of the waxing moon casting its silver beam on the river).  Progress.  That said, Turner’s patriotic feelings and sense of regret are also palpable – the stately splendour and ghostly colours of the old warship that had proved so valuable at Trafalgar a third of a century earlier in contrast to the dirty tugboat belching black clouds from its tall smokestack towing HMS Temeraire towards her final berth in Rotherhithe’s breaking yards.

I feel much the same about the changing UK electricity scene.