Biomass

Biomass Coal

Coal Gas

Gas Hydro

Hydro Interconnectors

Interconnectors Nuclear

Nuclear Oil

Oil Solar

Solar Storage

Storage Waste

Waste Wind

In 2008, each kilowatt hour of electricity generated in the UK adds 495 grammes of CO2 to the atmosphere (gCO2/kWh). This important metric – the “carbon intensity” of the electricity system – is to fall by nearly 60% by 2018. For now, electricity demand has been rising for decades and is close to record highs.

Although the face of the UK’s electricity system is starting to change, it is still dominated by large, centralised power plants – many of which were built decades earlier. Just 56 power stations burning coal, gas, oil or nuclear fuel account for the lion’s share of power capacity – shown in the stacked bar chart on the left – and generate the vast majority of UK electricity. Coal’s share of generation has halved since the dash for gas in the 1990s, but some four-fifths of UK electricity still comes from fossil fuels – with another 13% from nuclear.

Encouraged by the Non Fossil Fuel Obligation and then the Renewables Obligation, a sprinkling of renewable plants have begun to appear. There are now 552 larger renewable sites – mostly fuelled by hydro, wind and wastes such as landfill gas – and another 3,150 small installations, including 2,400 solar rooftops. [These small sites are aggregated to local authority level and are only shown on the map when they total at least 1 megawatt (MW).] Despite their numbers, renewables supply just 6% of the UK’s electricity.

In January, Medway Council approves a new coal-fired power station at Kingsnorth in Kent. If built, it would be the country’s first for 24 years. The “Kingsnorth six”, who scaled the chimney of the existing Kingsnorth plant to protest against the plans, are acquitted in September. A new Kingsnorth plant is needed, according to owners E.ON, to meet rising electricity demand and to replace old capacity as it retires. However, demand actually falls for the next decade.

January also sees the Labour government backing a new generation of nuclear power plants, with prime minister Gordon Brown saying the technology “can and will” help to meet climate goals. Evening Standard, 7 January 2008.

In May, the UK is hit by its worst blackouts for a decade after unexpected shutdowns including Sizewell B nuclear plant in Suffolk and the coal-fired Longannet in Scotland. Business secretary John Hutton tells that year’s Labour conference that new coal and nuclear plants are needed to “keep the lights on”. [The following month Hutton is reshuffled.]

During 2009, the carbon intensity of UK electricity falls 10% to 446gCO2/kWh, after nuclear plants return from a series of outages the previous year.

Along with falling demand due to the recession, coal’s share of the electricity mix shrinks to 27%. Another 50 large renewable sites are built, raising their number to 600 and their share of the electricity mix to 7%.

In October, energy firm E.ON postpones its plans to build a new coal plant at Kingsnorth in Kent, leading protestors to claim their “biggest victory” for the UK climate movement. E.ON blames its decision on weak electricity demand due to the recession, but says it is still competing for a share of government funding to build a CCS demonstration plant on the site. In December, the UN climate talks in Copenhagen end in “failure”. [This verdict is later challenged.]

In 2010, the carbon intensity of UK electricity rises marginally to 457gCO2/kWh as below-average wind and rainfall suppress renewable output.

In January, the Crown Estate announces the results of its “round 3” licensing for up to 32 gigawatts (GW) of offshore wind in nine development zones around the UK. The UK offshore wind fleet grows by two-fifths to 1.3GW. It had already become the world’s largest in late 2008.

Feed-in tariffs (FiTs) begin to support small-scale renewables from April, leading to a surge in capacity. The number of small wind, solar and hydro schemes leaps fivefold from around 5,000 in 2009 to 27,000 in 2010. By 2011, there are more than 200,000 projects supported by FiTs. Nevertheless, a government target to get 10% of UK electricity from renewables is missed, in part due to low wind speeds and little rain (the threshold goes on to be crossed two years late).

In 2011, the carbon intensity of electricity generated in the UK falls by 4% to 441gCO2/kWh. Renewables’ share of the UK mix climbs to around 10% as wind output jumps by more than half. In March, the Treasury publishes its “levy control framework” on limiting the low-carbon electricity subsidies that are added to consumer bills. The framework is later used as justification for subsidy cuts, even as its internal logic starts to crumble.

In April, the 1,000MW “BritNed” electricity interconnector opens between the UK and the Netherlands. It joins the 2,000MW link to France, which opened in 1986, and a 500MW link between Great Britain and Northern Ireland.

In 2012, the carbon intensity of UK electricity generation leaps by 10% to 484gCO2/kWh, as market prices drive a switch from gas to coal. The dirtiest fossil fuel generates 39% of the UK mix, up from 30% in 2011 and its highest share since 1996.

In January, Conservative backbencher and anti-wind campaigner Chris Heaton-Harris organises a letter to the prime minister demanding a “dramatic” cut in subsidies for “inefficient and intermittent” onshore wind. It is signed by more than 100 other MPs, mostly also Conservatives. The coalition government is “at war” over onshore wind for much of the year, with Conservative energy minister John Hayes sparking front pages in the Daily Telegraph (“Death knell for wind farms”) and the Daily Mail (“Minister signals end of the wind farm”). Sunday Times, 25 November 2012

In February, Oldbury nuclear power plant closes down after 44 years. The site in Somerset was the world’s oldest operating nuclear plant, having opened in 1967.

In October, a report for the “libertarian” US thinktank the Reason Foundation reflects a widespread talking point by arguing there is a 10% “practical upper limit” to the share of electricity generated by windfarms. The report, later republished with the free-market UK thinktank the Adam Smith Institute, cites barriers including the need for storage and a “decrease in grid reliability”. UK wind goes on to comfortably surpass this supposed limit in 2015, without incident.

In December, two major power plants close after choosing not to upgrade to meet EU air pollution rules under the Large Combustion Plants Directive. One is the 1.9GW Kingsnorth coal plant in Kent, where protestors had scaled the chimney in 2007. The other is the oil-fired 1.3GW plant at Grain, also in Kent. They are followed by four more closures during 2013, totalling 5.1GW.

Around the same time, two large gas plants are completed: a 2.2GW site at Pembroke on the coast of south Wales and a 1.3GW station at West Burton in Nottinghamshire. The latter is occupied by “No Dash for Gas” protestors, delaying the start of operations into 2013. The new sites join four other large gas plants that had opened in 2010. These are the Severn Power site in Wales, Staythorpe C in Nottinghamshire, Langage in Devon and the Grain combined heat and power scheme in Kent. These take the total of new gas capacity to 8.4GW opened in the space of just three years. (Some 8GW of large new gas plants had opened in the decade to 2010.) The government’s new “gas generation strategy” says up to another 26GW of new gas-fired power stations could still be needed by 2030 “in part to replace older coal, gas and nuclear plant as it retires”. The strategy – unveiled by chancellor George Osborne while energy and climate change secretary Ed Davey is at a UN summit in Doha – is linked to support for fracking and says as much as 37GW could be needed if climate goals are relaxed. This level of new gas is branded “completely incompatible” with UK carbon budgets by the head of the CCC, who does however support the 26GW scenario. [Only one large new gas plant goes on to be built by 2019.]

In 2013, the carbon intensity of UK electricity generation falls to 452gCO2/kWh after another sharp increase in output from the country’s expanding fleet of windfarms.

There are now more than 1,000 large renewable energy schemes across the UK – double the number in 2008 – and nearly half a million small sites, mostly solar rooftops. With nuclear, a third of UK electricity is now low-carbon.

In April, the UK’s carbon price support is introduced at £5 per tonne of CO2 for emissions from the power sector, paid in addition to the cost of the EU Emissions Trading System. At least initially, it is disliked by industry, consumer and green groups. Moreover, despite the measure raising their costs relative to gas-fired power stations, coal plants retain a 35% share of the UK mix in 2013. Indeed, many gas plants sit idle across Europe, or have been temporarily taken out of service (“mothballed”). Weak demand and the rise of renewables is hitting utility firm profits. Since 2008, the top 20 European utilities have lost “half a trillion euros” – or half their value.

Later in April, the UK’s largest power plant at Drax in Yorkshire converts one of its six units to burn biomass wood pellets instead of coal. It goes on to convert four of the six units to use the fuel, which is kept dry in giant golf-ball shaped storage domes. That year, former coal plants at Ironbridge in Shropshire and Tilbury in Essex are also running on biomass. They close soon after.

In July, prime minister David Cameron opens the world’s largest offshore windfarm, the 630MW London Array in the Thames estuary. It holds the title for five years.

At the Labour conference in September, opposition leader Ed Miliband says rising household energy bills should be frozen, an idea Cameron brands as “Marxist”. (His Conservative successor, Theresa May, goes on to adopt a similar policy.) Later in the year, a Sun front page splash suggests Cameron has his own solution to rising bills: “Get rid of the green crap.” His government cuts support for the energy efficiency measures that have helped limit increases, leading to a 90% fall in the rate of improvements. The Sun, 21 November 2013

The Liberal Democrat conference votes in favour of a new generation of nuclear power plants. Lib Dem energy and climate secretary Ed Davey had said it would be “reckless” to oppose new nuclear in the face of a warming planet. The next month, the government signs a deal with French energy giant EDF to build the Hinkley C new nuclear plant for £92.50/MWh. It will be the UK’s first new nuclear plant since Sizewell B was completed in 1995. In December, the Energy Act 2013 receives royal assent, enacting the coalition’s “electricity market reforms” of competitive auctions for low-carbon power and a capacity market to secure supplies.

In 2014, the carbon intensity of UK electricity generation drops 11% to 401gCO2/kWh – a record low – as coal’s share of the mix falls back below 30%.

There are just 13 large coal or oil-fired power stations remaining in the UK, down from 19 in 2008. Renewables now supply a fifth of UK electricity – more than nuclear for the first time – from more than 600,000 small installations and 1,400 larger sites.

In 2015, the carbon intensity of electricity drops by 17% to 332gCO2/kWh as coal continues to decline. Renewables increase their share to a record quarter of the overall mix – overtaking coal for the first time – and there are now nearly 800,000 sites around the UK running on wind, solar, hydro, biomass or wastes. This pushes low-carbon electricity up to 46% of the UK mix.

During the year, another five major power plants totalling 8GW close down rather than invest to meet EU air pollution rules. These are the oil-fired Littlebrook D in Kent and coal plants at Lynemouth in Northumberland, Longannet in Scotland, Ironbridge in Shropshire and Ferrybridge C in Yorkshire. (Lynemouth is later converted to burn biomass.)

In 2016, the carbon intensity of UK electricity drops by nearly a quarter to 256gCO2/kWh after coal-fired generation drops by two-thirds. Gas generation fills the gap with its only significant year-on-year increase of the decade, but remains well below levels seen between 2008 and 2010. The decline of coal means it generates less of the UK’s electricity than wind for the first time. The idea of giving “subsidy free” contracts to windfarms loses momentum after being described in a Sunday Telegraph frontpage splash as “the great wind farm tax ‘con’”. It is never implemented. The Sunday Telegraph, 14 February 2016 In March, the newly formed National Infrastructure Commission says the UK could save up to £8bn a year by 2030 if it embraces the “smart power revolution” overtaking the energy sector, as ageing power stations retire to be replaced by low-carbon sources of electricity.

In April, Carbon Brief analysis reveals the first-ever day where the country’s solar panels generate more electricity than coal. This is quickly followed by the first week, month and half year where solar outstrips coal.

In 2017, the carbon intensity of UK electricity generation falls to 226gCO2/kWh as coal output continues its rapid decline.

For first time, low-carbon sources generate more than half the UK total, Carbon Brief analysis reveals. This is double their contribution in 2009, when 73% of generation was from fossil fuels. Coal and gas generation both decline, offset by a large increase in the output from windfarms as their capacity rises by a fifth.

In 2018, the carbon intensity of UK electricity generation falls again to just 207gCO2/kWh – a reduction of nearly 60% compared to 495g in 2008 and more than half since 484g in 2012.

There are just seven coal plants remaining in the UK supplying less than 5% of the electricity mix. Gas generation has been ever-present and meets nearly 40% of UK demand – but its output has declined, too, falling 25% since 2008. Nuclear still supplies around a fifth of the total. Coal capacity has shrunk from 32GW in 2008 to just 12GW, with another 2GW set to close in 2019. In contrast, the UK’s wind and solar capacity has exploded. Solar has gone from being close to zero in 2008 to 13GW, while wind has increased six-fold from 3.6GW to nearly 22GW. The capacity of the country’s gas and biomass power plants has also gone up by around 5GW each. Meanwhile, more than 700 megawatts (0.7GW) of battery storage capacity has been built in the space of two years, with another 220MW in the pipeline.

In 2008, just 56 major power plants burning coal, oil, gas or nuclear fuel generated the vast majority of UK electricity and the roughly 500 large renewable sites around the country contributed only 6% to the mix. Now, there are nearly 3,000 large renewable schemes and more than 800,000 small sites, collectively generating more than a third of the mix.

In March, the iconic chimney stack at the former Kingsnorth coal plant in Kent is demolished, a decade after it had been scaled by anti-coal protestors. Later in the year, the 660MW Walney offshore windfarm opens off the coast of Cumbria, overtaking the London Array to become the world’s largest.

The Committee on Climate Change, the government’s official climate adviser, publishes two significant reports. One suggests the UK should “move away” from the large-scale burning of biomass to generate electricity, once existing subsidy contracts for sites such as Drax in Yorkshire and Lynemouth in Northumberland expire in 2027. The other says it could be cheaper to build new renewables in the 2020s than to keep running existing gas plants.

Meanwhile, the National Infrastructure Commission says a “quiet revolution” in renewable costs means government should prioritise wind and solar, alongside energy efficiency, as it looks to the low-carbon economy of the future. In June, the government agrees a “sector deal” with the nuclear industry, which commits to “reduce the cost of new nuclear build projects by 30% by 2030”. [It does not say what this is compared to.] In November, business secretary Greg Clark gives a speech proclaiming the imminent “end of the trilemma”. The trilemma was the idea that electricity supplies can meet only two out three competing priorities: cheap, secure or low-carbon. This trade-off will be “well and truly over” by the mid-2020s, Clark says, as “green power will be the cheapest”. The shift in rhetoric continues when Clark explains to parliament in early 2019 why the Wylfa new nuclear plant in Wales will not be going ahead despite strong continued government support for the technology. Clark says: “The economics of the energy market have changed significantly in recent years. The cost of renewable technologies such as offshore wind has fallen dramatically…The challenge of financing new nuclear is one of falling costs and greater abundance of alternative technologies, which means that nuclear is being outcompeted.” In the first half of 2019, Great Britain extends its record for running without coal-fired electricity, first to one week, then two weeks, then 18 days in a stretch.

The past decade of transformation in the UK’s electricity sector is a prelude to much greater change in the years to come, as the country moves towards the zero-carbon grid that will be needed to meet a recommended long-term climate goal of reaching net-zero emissions by 2050. Since 2008, electricity demand has fallen to its lowest level in decades, thanks to energy efficiency policies and other factors, easing the transition away from fossil fuels. Nuclear has held steady while renewables have come of age, now generating a third of UK electricity. Coal has all but disappeared. Gas continues to be an essential part of the mix, even as it too has declined.

By 2025, the UK’s last coal-fired power station will have closed and by the 2030s all but one of the UK’s existing nuclear plants is due to have retired. Only one new nuclear plant – Hinkley Point C in Somerset – is currently being built. Meanwhile, some 1GW of onshore windfarms could retire by 2030 and would need to be “repowered” with new turbines or their output replaced elsewhere.

Some 15GW of gas-fired power stations were built before 2000 and are also likely to have retired by 2030. On the other hand, some 30GW of new gas is under development, though much of this remains unconfirmed. Either way, to meet the UK’s climate goals, gas generation will have to decline from its current 40% share down to around 25% of the mix or below.

The gap left by nuclear and fossil fuels will mainly be filled by renewables – chiefly, via the government’s favoured choice of offshore wind. The government-industry offshore wind sector deal has pledged to meet a third of UK electricity demand in 2030, with projects costing less than fossil fuel generation by 2020. This deal, as well as CCC projections, see offshore wind capacity topping 30GW by 2030, with the first new projects already contracted and shown on the “future” map.

A proliferation of new undersea interconnectors will link the UK with other markets, helping to balance supply and demand, even as output from wind and solar plants varies across hours, months and seasons. Some 14GW of new links are planned or already under construction, to countries including France, the Netherlands, Denmark and Norway.

Battery storage sites are also set to quickly expand in the years ahead, from some 0.7GW today to more than 3GW in the early 2020s – with nearly 5GW having already received planning permission, according to trade body RenewableUK.