Britain now generates twice as much energy from wind as from coal

Burbo Bank wind farm, in the river Mersey. Image: Getty.

Just six years ago, more than 40 per cent of Britain’s electricity was generated by burning coal. Today, that figure is just 7 per cent. Yet if the story of 2016 was the dramatic demise of coal and its replacement by natural gas, then 2017 was most definitely about the growth of wind power.

Wind provided 15 per cent of electricity in Britain last year (Northern Ireland shares an electricity system with the Republic and is calculated separately), up from 10 per cent in 2016. This increase, a result of both more wind farms coming online and a windier year, helped further reduce coal use and also put a stop to the rise in natural gas generation.

Great Britain’s annual electrical energy mix 2017. Author calculations from data sources: National Grid and Elexon.

In October 2017, the combination of wind, solar and hydro generated a quarter of Britain’s electricity over the entire month, a new record helped by ex-hurricane Ophelia and storm Brian.

Great Britain’s annual electrical energy mix 2017 per month (note: nuclear and gas not shown). Author calculations from data sources: National Grid and Elexon.

Since that record month, large new offshore wind farms have started to come online. Dudgeon began generating off the Norfolk coast, as did Rampion, which can be seen from Brighton town centre.

In all, Britain’s wind output increased by 14 terawatt hours between 2016 and 2017 – enough to power 4.5m homes. To give a sense of scale, this increase alone is more than the expected annual output from one of the two new nuclear reactors being built at Hinkley Point C.

Not only is offshore wind growing fast, it is also getting much cheaper. When the latest round of government auctions for low-carbon electricity were awarded last year, two of the winning bids from offshore wind developers had a “strike price” of £57.50 per megawatt hour (MWh). This is considerably cheaper than the equivalent contract for Hinkley Point of £92.50/MWh (in 2012 prices).

Rampion wind farm begins about 13km offshore from Brighton. Image: Dominic Alves/Flickr/creative commons.

Although these wind farms won’t be built for another five years, this puts competitive pressure on other forms of low-carbon electricity. If there is to be a nuclear renaissance, or if fossil fuels with carbon capture and storage are to become a reality, these industries will have to adjust to the new economic reality of renewable energy.

Britain is using less electricity

Overall demand for electricity also continued its 12-year downward trend. More of the electricity “embedded” in the products and services used in the UK is now imported rather than produced at home, and energy efficiency measures mean the country can do more with less. This meant Britain in 2017 used about as much electricity as it did way back in 1987 – despite the considerable population growth.

At some point this trend will reverse though, as electric vehicles and heat pumps become more common and electricity partly replaces liquid fuels for transport and natural gas for heating respectively. One major challenge this brings is how to accommodate greater seasonal and daily variation in the electricity system, without resorting to the benefits of fossil fuels, which can be pretty cheaply stored until required.

Electricity generated in Britain is now the cleanest it’s ever been. Coal and natural gas together produced less than half of the total generated. Britain’s electricity was completely “coal free” for 613 hours last year, up from 200 hours in 2016. This position would be wholly unthinkable in many countries including Germany, India, China and the US, which still rely heavily on coal generation throughout the year.

Great Britain’s annual electrical energy mix - fossil fuels drop below 50 per cent for first time. Author calculations from data sources: National Grid and Elexon.

However, the low level of coal generation over 2017 masks its continued importance in providing capacity during hours of peak demand. During the top 10 per cent hours of highest electrical demand, coal provided a sixth of Britain’s electricity. When it matters most, coal is relied on more than nuclear, and more than the combined output from wind + solar + hydro. Additional energy storage could help wind and solar meet more of this peak demand with greater certainty.

Looking forward to this year, we would be surprised if wind generation dropped much from its current levels. Last year wasn’t even particularly windy compared to the longer-term average, and more capacity will be coming online. Equally, it would be surprising if solar and hydro combined produced significantly less than they did last year.

It is therefore inevitable that another significant milestone will be reached this year. At some point, for several hours, wind, solar and hydro will together, for the first time, provide more than half of Britain’s electricity generation. This goes to show just how much a major power system can be reworked within a decade.


The ConversationThe data used in this article is based on the Energy Charts and Electric Insights websites, which allow readers to visualise and explore data on generation and consumption from Elexon and National Grid. Data from other analyses (such as BEIS or DUKES) will differ due to their methodology, particularly by including combined heat and power, and other on-site generation which is not monitored by National Grid and Elexon. Our estimated carbon emissions are based on Iain Staffell’s research published in Energy Policy, and account for foreign emissions due to electricity imports and biomass fuel processing.

Grant Wilson, Teaching and Research Fellow, Chemical and Biological Engineering, University of Sheffield and Iain Staffell, Lecturer in Sustainable Energy, Imperial College London.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

Here’s why we’re using a car wash to drill into the world’s highest glacier on Everest

Everest. Image: Getty.

For nearly 100 years, Mount Everest has been a source of fascination for explorers and researchers alike. While the former have been determined to conquer “goddess mother of the world” – as it is known in Tibet – the latter have worked to uncover the secrets that lie beneath its surface.

Our research team is no different. We are the first group trying to develop understanding of the glaciers on the flanks of Everest by drilling deep into their interior.

We are particularly interested in Khumbu Glacier, the highest glacier in the world and one of the largest in the region. Its source is the Western Cwm of Mount Everest, and the glacier flows down the mountain’s southern flanks, from an elevation of around 7,000 metres down to 4,900 metres above sea level at its terminus (the “end”).

Though we know a lot about its surface, at present we know just about nothing about the inside of Khumbu. Nothing is known about the temperature of the ice deeper than around 20 metres beneath the surface, for example, nor about how the ice moves (“deforms”) at depth.

Khumbu is covered with a debris layer (which varies in thickness by up to four metres) that affects how the surface melts, and produces a complex topography hosting large ponds and steep ice cliffs. Satellite observations have helped us to understand the surface of high-elevation debris-covered glaciers like Khumbu, but the difficult terrain makes it very hard to investigate anything below that surface. Yet this is where the processes of glacier movement originate.

Satellite image of Khumbu glacier in September 2013. Image: NASA.

Scientists have done plenty of ice drilling in the past, notably into the Antarctic and Greenland ice sheets. However this is a very different kind of investigation. The glaciers of the Himalayas and Andes are physically distinctive, and supply water to millions of people. It is important to learn from Greenland and Antarctica, – where we are finding out how melting ice sheets will contribute to rising sea levels, for example – but there we are answering different questions that relate to things such as rapid ice motion and the disintegration of floating ice shelves. With the glaciers we are still working on obtaining fairly basic information which has the capacity to make substantial improvements to model accuracy, and our understanding of how these glaciers are being, and will be, affected by climate change.

Under pressure

So how does one break into a glacier? To drill a hole into rock you break it up mechanically. But because ice has a far lower melting point, it is possible to melt boreholes through it. To do this, we use hot, pressurised water.

Conveniently, there is a pre-existing assembly to supply hot water under pressure – in car washes. We’ve been using these for over two decades now to drill into ice, but our latest collaboration with manufacturer Kärcher – which we are now testing at Khumbu – involves a few minor alterations to enable sufficient hot water to be pressurised for drilling higher (up to 6,000 metres above sea level is envisioned) and possibly deeper than before. Indeed, we are very pleased to reveal that our recent fieldwork at Khumbu has resulted in a borehole being drilled to a depth of about 190 metres below the surface.

Drilling into the glacier. Image: author provided.

Even without installing experiments, just drilling the borehole tells us something about the glacier. For example, if the water jet progresses smoothly to its base then we know the ice is uniform and largely debris-free. If drilling is interrupted, then we have hit an obstacle – likely rocks being transported within the ice. In 2017, we hit a layer like this some 12 times at one particular location and eventually had to give up drilling at that site. Yet this spatially-extensive blockage usefully revealed that the site was carrying a thick layer of debris deep within the ice.

Once the hole has been opened up, we take a video image – using an optical televiewer adapted from oil industry use by Robertson Geologging – of its interior to investigate the glacier’s internal structure. We then install various probes that provide data for several months to years. These include ice temperature, internal deformation, water presence measurements, and ice-bed contact pressure.


All of this information is crucial to determine and model how these kinds of glaciers move and melt. Recent studies have found that the melt rate and water contribution of high-elevation glaciers are currently increasing, because atmospheric warming is even stronger in mountain regions. However, a threshold will be reached where there is too little glacial mass remaining, and the glacial contribution to rivers will decrease rapidly – possibly within the next few decades for a large number of glaciers. This is particularly significant in the Himalayas because meltwater from glaciers such as Khumbu contributes to rivers such as the Brahmaputra and the Ganges, which provide water to billions of people in the foothills of the Himalaya.

Once we have all the temperature and tilt data, we will be able to tell how fast, and the processes by which, the glacier is moving. Then we can feed this information into state-of-the-art computer models of glacier behaviour to predict more accurately how these societally critical glaciers will respond as air temperatures continue to rise.

The ConversationThis is a big and difficult issue to address and it will take time. Even once drilled and imaged, our borehole experiments take several months to settle and run. However, we are confident that these data, when available, will change how the world sees its highest glacier.

Katie Miles, PhD Researcher, Aberystwyth University and Bryn Hubbard, Professor of Glaciology, Aberystwyth University.

This article was originally published on The Conversation. Read the original article.