Carbon capture has failed. So what should we do instead?

Drax and Eggborough power stations in England. Image: Pete Richman/creative commons.

For years, optimists have talked up carbon capture and storage (CCS) as an essential part of taking emissions out of electricity generation. Yes, build wind and solar farms, they have said, but they can’t be relied on to produce enough power all the time. So we’ll still need our fleet of fossil-fuel-burning power stations; we just need to stop them pumping carbon dioxide (CO₂) into the atmosphere.

Most of their emphasis has been on post-combustion capture. This involves removing CO₂ from power station flue gases by absorbing them into an aqueous solution containing chemicals known as amines.

You then extract the CO₂, compress it into a liquid and pump it into a storage facility – the vision in the UK being to use depleted offshore oil and gas fields. One of the big attractions with such a system is it could be retrofitted to existing power stations.

The big let-down

But ten years after the UK government first announced a £1bn competition to design CCS, we’re not much further forward. The reason is summed up by the geologist Lord Oxburgh in his contribution to the government-commissioned report on CCS published last year:

There is no serious commercial incentive and it will stay that way unless the state demonstrates there is a business there.

The problem is that the process is costly and energy intensive. For a gas-fired power station, you typically have to burn 16 per cent more gas to provide the capture power. Not only this, you end up with a 16 per cent increase in emissions of other serious air pollutants like sulphur dioxide, nitrogen oxides and particulate matter. Concerns have also been expressed about the potential health effects of the amine solvent used in the carbon capture.

You then have to contend with the extra emissions from processing and transporting 16 per cent more gas. And all this before you factor in the pipeline costs of the CO₂ storage and the uncertainties around whether it might escape once you’ve got it in the ground. Around the world, the only places CCS looks viable are where there are heavy state subsidies or substantial additional revenue streams, such as from enhanced oil recovery from oilfields where the CO₂ is being pumped in.

Well, say the carbon capture advocates, maybe another technology is the answer. They point to oxy-combustion, a system which is close to reaching fruition at a plant in Texas.

First proposed many years ago by British engineer Rodney Allam, this involves separating oxygen from air, burning the oxygen with the fossil fuel, and using the combustion products – water and CO₂ – to drive a high-pressure turbine and produce electricity. The hot CO₂ is pressurised and recycled back into the burners, which improves thermal efficiency. It has the additional advantage that CO₂ is also available at pressures suitable for pipeline transportation.

It is, according to some enthusiasts, the “holy grail” of CCS. Admittedly it looks promising, but I wouldn’t go that far. It’s not suitable for retrofitting existing power stations. With many existing stations viable for several decades, this will do little for immediate emissions. And you are still obtaining and moving fossil fuels in large quantities, with the resultant emissions along the way. Finally, my experience would indicate that there is always very significant cost growth with new technology scaled up to industry.

Number crunching

One UK post-combustion CCS project that was cancelled earlier this year was the joint-venture between SSE and Shell at the Peterhead gas-fired ation in northeast Scotland. It aimed to capture 10m tonnes of CO₂ over a 10-year period and store it 2km under the North Sea.

Let’s put this saving into context. The diagram below summarises the amount of power produced and used in the UK. It shows that the country uses 108 terawatt hours (TWhrs) of domestic electricity per annum.

 

UK electricity generation/consumption. All numbers are in terawatt hours (TWhrs). Image: DECC.

Of this domestic usage, 16 per cent goes to cooking. Boiling kettles makes up 34 per cent – that’s 5.9TWhrs per annum, the equivalent of a 670MW power station. Domestic kettle use is particularly inefficient as we regularly overfill our kettles. We could save at least half the energy if we boiled only what we need to make tea and coffee.

That would negate the need for 335MW of power. Now compare that to what CCS would have saved from Peterhead – 85 per cent of a 400MW gas turbine, or 340MW. Simply by not overfilling our kettles, we could remove about the same amount of CO₂. Unlike CCS, let alone oxy-combustion, we could do this immediately, for free, and cut our electricity bills and remove various air pollutants at the same time.

Of course, being kettle smart will only deliver a fraction of the UK’s required carbon reduction goals. It’s only about 3TWhrs out of the approximately 170TWhrs produced by gas-fired power in the UK each year. But it hopefully illustrates why energy efficiency is a much smarter way of reducing carbon and other harmful air emissions than CCS.


If we took the same approach to lighting, computer monitors, TVs on stand-by, running water and everything else, it becomes a very different proposition. If we could achieve the aim of a carbon-neutral house, we could shut down half the UK’s existing gas-fired power stations. And if industry and other non-domestic consumers made energy savings of the order of 20 per cent, that would bring down the gas-fired power requirement by a corresponding percentage.

Is 20 per cent realistic? As a chemical engineer with a 40-year industrial career, I am confident it is. Key areas to be considered would be pump and compressor efficiency, energy use in separation processes, combined heat and power, furnace fuel management, green concrete and energy integration.

Together with the government giving greater priority to renewable energy like offshore wind and solar, you have a viable plan for delivering the UK’s carbon goals. CCS may still have its place, but as a means of removing carbon emissions from burning things like wood and rubbish as opposed to fossil fuels. Suffice to say it looks more promising on that front.

The ConversationBut in short, it is time for governments to stop wasting time and money on technologies like CCS that aren’t working. They need to finally get serious about leading a major drive for energy efficiency instead.

Tom Baxter is senior lecturer in chemical engineering at the University of Aberdeen.

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

 
 
 
 

You’ve heard of trainspotters and planespotters. Now meet Britain’s growing army of busspotters

Some busspotters in action. Image: Damian Potter.

In the summer of 2014, with too much time on my hands and too little to do, I found myself in the middle of an incredibly active, 200+ person Facebook group. How I ended up here (record scratch, freeze frame) is a little too convoluted and stupid to explain – but what I found was a world that I a) could not have imagined nor b) had any clue even existed.

The group I tumbled into was what I now understand to be a very, very small example of a “busspotting” group – that is, a Facebook group full of dedicated bus enthusiasts which exists to share pictures of buses they see on the road. This group had members from all over the country, with a concentration on northern buses, and was predominantly filled with young, white men.

What I expected to see was a range over relatively interesting buses, holding some significance or another, that were tough to find in your average day-to-day life. This was, largely, not the case. What fascinated me was that the vast majority of the group was not focused on unique buses, new buses, historically significant buses, and so on – but simply on the average bus and or bus route you might take just to get around your city.

What was even more bizarre to me was that people from across the country were meeting up in small towns (Morpeth, Livingston, Stevenage) to take seemingly mundane bus rides to other equally small places (Washington, Gloucester, Grimsby). The busspotters would travel hours on end to meet at these locations simply to ride this bus, often for three or four hours, and experience a bus route they’d never been on before or one that they just particularly enjoyed.

Ooooh. Image: Damian Potter.

After a couple of weeks of silently watching and one semi-ironic post, I left the group. And, for the next three years, I gave barely a thought to bus enthusiasm, as no busspotter group/page/person crossed my path. Unlike similar enthusiasms like planespotting and trainspotting, it didn’t seem to me that busspotting had any significant following.

But, as is the way of these things, a weird thread on Twitter three summers later sparked my memory of my short time in this group. I wanted to see what busspotting was actually and about and if, in fact, it was still a thing.

So I spoke to Damian Potter, an admin on several popular busspotting groups, about what it’s like to be deep into the busspotting scene.

“I used to sit upstairs on double decker buses and 'drive' them, including the pedal movements!” Damian announced right off the bat, speaking of his childhood. “I've been driving coaches at home and abroad since I passed my PCV test in 1994. I've been driving for Transdev Harrogate and District Travel since 1998.”

Damian, as you might have gathered, has been a busspotter since his early youth. Now, at the age of 50, he manages four different busspotting Facebook groupsm, mostly based around the Harrogate area (Transdev Enthusiasts, The Harrogate Bus Company, iTransport Worldwide and Spotting Bus and Coach Spotters). Some of them have over a thousand members.

He also participates in busspotting IRL, travelling around the country participating in busspotting meet-ups and events and co-organising trips along different bus routes. When I asked him what busspotting was to him, he explained that it can manifest in different ways: some people focus on makes of bus and routes, other focus on particular bus companies (National Express is particularly popular). Of course, bus enthusiasm is not solely a British phenomenon, but busspotters can certainly be found in practically every corner of the UK.

“People tend to think that spotters hang around bus stations furtively, with a camera and some curly cheese sandwiches, but this isn't really the case,” Damian continued. That said, he also mentioned some particularly hardcore bus nuts who have been known to trespass on company premises to be the first to snap a picture of a new bus.

“They really do produce some brilliant pictures, though,” he added.


Although much of busspotting culture happens online, predominantly on Facebook, groups often have what are called ‘running days’ which involve meet ups having to do with particular routes. Damian mentioned one particularly popular day following the London Routemaster buses that happen periodically. Not only do these routes draw in enthusiasts, he noted, but also draw huge numbers of tourists who want to claim they’ve ridden on the original London buses.

“I reckon the general public miss the old Routemaster buses. There is only one 'heritage' route in London which still uses Routemaster buses and that's the 15 service between Trafalgar Square and Tower Hill.”

Despite this widespread interest in buses and bus history, though, busspotters often find themselves treated as the lesser of the motor enthusiasts. This became clear to me almost immediately when speaking to Damian, and continued to strike me throughout our conversation; without my saying anything sarcastic, malicious, or snarky, he became instantly defensive of his fellow enthusiasts and of his hobby.

When I asked him why he felt this immediate need to defend busspotting, he explained that people often ridicule busspotters and bus enthusiasm generally, arguing that bus drivers are the most common attackers. “However,” he noted, “if I bring a load of pictures into the canteen they're the first to crowd around to see bus pictures...”

Aaah. Image: Damian Potter.

Despite being perceived as an often-mocked hobby, bus enthusiasm is expanding rapidly, Damien claims. “The bus enthusiast culture is growing, with younger generations getting more involved.” Drawing in new, younger enthusiasts has become easier thanks to social media, as has creating real personal connections. Social media has made it easier for bus enthusiasm to not just stay afloat, but actually thrive over the last several years.

It’s so widespread, in fact, that a national competition is held every year in Blackpool to mark Bus Driver of the Year (Damian himself came in 34th out of 155 back in 2002). This event draws in everyone from the bus world – drivers, manufacturers, tour companies, and enthusiasts alike. Here is one of the many places where great friendships are forged and busspotters who’ve only known each other online can finally meet face-to-face. “Personally I have made some great friends through Facebook,” Damian told me. “I have even stayed over at a friend's house in London a couple of times.”

Busspotting may be less well-known than motor enthusiasms like planespotting and trainspotting, but that very well could change. Thanks to active social media groups and regular in-person meet-ups, people have been able to use busspotting forums as not only a way to find lifelong friends, but also spend more of their free time exploring their hobby with the people they’ve met through these groups and pages who share their enthusiasm. For all the flack it may receive, the future of busspotting looks bright.

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