Andrew Crossland, Associate Fellow, Durham Energy Institute, Durham University and Jon Gluyas Professor of Geoenergy, Carbon Capture and Storage, Durham University. In the past ten years the UK’s electricity mix has changed dramatically. Coal’s contribution has dropped from 40% to 6%. Wind, solar power and hydroelectric plants now generate more electricity than nuclear power stations, thanks to rapid growth. Demand for electricity has also fallen, reducing the country’s dependence on fossil fuels. Thanks to these three factors, the carbon intensity of Britain’s electricity has almost halved, from more than 500g of CO₂ per kilowatt-hour in 2006 to less than 270g in 2018. Progress has been so quick that a fully low-carbon power sector in Britain has transformed from a faint pipedream into a real possibility, according to the CEO of one of the UK’s “big six” energy companies. Indeed, the National Grid now expects to be able to operate a zero-carbon electricity system by 2025. Already approaching that milestone on windy, sunny days, the country’s first hours of 100% low-carbon electricity could soon be here – but staying at 100% throughout the year will be much more difficult to achieve. So what does the journey to decarbonisation look like? When the wind is weak and the skies dark, low-carbon sources provide less than 25% of electricity generation. On average, low-carbon technologies accounted for more than 45% of British electricity in 2018 – and almost half of that came from nuclear plants. Saying goodbye to fossil fuels quickly might mean accepting that the ever-controversial form of energy will play some role in the UK’s electricity mix in the medium term. Even with the aid of nuclear power, electricity consumption in Britain is set to increase dramatically in the coming decade. As electric cars continue their journey to the mainstream, traditional transport fuels will be replaced by electricity. The yearly energy demand of transport fuels is currently more than double the UK’s national electricity consumption. Similarly, plans to decarbonise the UK’s heat generation – currently 66% is generated by gas – by converting to electric heating systems will also place huge pressures on demand. During winter months, heat can consume more than three times the daily energy demands of electricity – and over a full annual cycle it constitutes 50% of total energy demand. Collectively, these factors will move the goalposts for 100% low-carbon electricity further and further away. The tens of billions of pounds already invested in low-carbon electricity is just the start of the UK’s journey to decarbonised energy. It also means seeking alternative, non-electric methods to replace fossil fuels in heat generation. Capturing waste heat from industrial processes, geothermal heat from the ground and heat extracted from water bodies could all limit demands on the electricity sector and make it easier to achieve more low-carbon heat and power. Southampton already heats much of its city centre geothermally – and many cities can and should follow suit. Recent work published by the BritGeothermal estimates that geothermal energy alone could meet the UK’s heat demand for at least 100 years.
The Conversation 9th April 2019 read more »