CAT’s Paul Allen joined the International Network For Sustainable Energy (INFORSE) in Denmark to share the latest Zero Carbon Britain research on a global platform. The 25th anniversary meeting brings together organisations from across the world to explore the transition to sustainable energy, community power and the development of new initiatives and projects.
Imagine a world where we have broken our ties with fossil fuels… Our towns and cities are awash with innovative practical projects that are rebuilding our relationship with food, energy, transport and buildings, openly supported by the wider economic and political systems. Such innovation has unleashed all kinds of co-benefits, from cleaner air to better diets, more jobs and income arising across the local area.
John Butler reports from the latest module of the MSc Sustainability and Adaptation courses at CAT. John is a student on the MSc Sustainability and Adaptation in the Built Environment course. He normally blogs on his site http://thewoodlouse.blogspot.com/ and you can follow him on Twitter @the_woodlouse.
The March module of CATs Sustainability and Adaptation MSc was part B of Energy Flows in Buildings. Part A (in February) introduced us to ideas of thermal comfort and its relation to heat transfers from the human body to its surroundings. This was tied to the implications of maintaining that thermal comfort, and the impact on energy use. We learnt about calculating U-Values (used as a standard measure of the thermal efficiency of a building element), and daylighting: making best use of natural daylight in a building and calculating the resulting energy savings.
Part B expanded on this getting into more detail about limiting the flows of energy through a building, whilst addressing issues around ventilation and movement of moisture. A sustainable building should maintain a comfortable environment – comfortably warm in winter, comfortably cool in summer, ideal humidity levels, good air quality – with minimal energy input, and without moisture ingress causing degradation of the building fabric. Throughout the week different elements of possible means to achieve this were discussed.
A recurring theme throughout the week was retrofit – upgrading the thermal efficiency of existing buildings to reduce their energy use and related CO2 emissions. The most commonly stated best-estimate is that around 80% of existing houses will still be in use by 2050; the potential contribution to reduced energy use and emissions from such a large number of buildings is huge, but presents a challenge. There are advantages and disadvantages to various approaches, from aesthetic considerations (eg: changing the appearance of a building when externally insulating it), to practical (eg: loss of space when internally insulating), to technical (eg: the risk of condensation forming at the meeting of new insulation and existing structure if it is not carefully considered). Planning and conservation concerns can also influence or restrict choices for retrofit.
There are also issues and trade-offs surrounding choice of insulation materials – the most highly efficient materials may have a greater overall environmental impact than some less efficient materials. Some are more breathable (open to passage of moisture vapour) than others, which can have both positive and negative implications, depending on application.
Another recurring theme was the need to account for future changes to our climate in both retrofit and new build. In particular, too much emphasis on designing to conserve heat could lead to overheating further down the line when atmospheric temperatures increase. Careful attention to placement of glazing and shading to control solar gain can help address this, allowing direct sunlight in to provide warmth in winter when the sun’s path is lower, and sheltering the building from the most intense direct sunlight in summer when the sun is higher.
The role of thermal mass in regulating internal temperatures was discussed in a number of lectures. Depending on climate and design, thermal mass may hang on to winter day-time heat, releasing it within the building through the night – or assist cooling by absorbing excess heat in summer, if combined with effective ventilation to purge that heat at night. Used inappropriately thermal mass may add to overheating, so its use must be considered carefully.
A practical in the second half of the week provided a demonstration of heat loss through unplanned ventilation (ie: draughts). This was linked to the need to provide controlled ventilation (whether through opening windows or via mechanical ventilation), and highlighted the difficulties of achieving airtightness (eliminating draughts) in some existing buildings. The practical involved carrying out an air-pressure test to establish the air-permeability of the timber-framed selfbuild house on the CAT site (ie: how much air moved through the fabric of the building at a certain pressure). In groups we surveyed the building with thermal imaging cameras, before and during the test. The resulting images clearly showed how the cold incoming air cooled surrounding surfaces, demonstrating the impact of air infiltration on energy use. A scheme to retrofit the selfbuild house at CAT would have to include a means to reduce this.
The end of the week saw us discussing Passivhaus and visiting the Hyddgen Passivhaus office/community building in Machynlleth, with the building’s designer John Williamson. Some myths about Passivhaus were busted (for instance: you can open windows), and the physics-based fabric-first approach was explained. The standard is based around high comfort levels combined with incredibly low energy input. While on site we investigated the MVHR unit (Mechanical Ventilation with Heat Recovery), which removes stale air from the building, and uses it to heat fresh incoming air. These are a common feature of passivhaus, as they allow the removal of moist air and other airborne contaminants and it’s replacement with fresh air, whilst minimising heat loss. This system has been the subject of some heated debates with fellow students at CAT, due to questions about the amount of energy needed to run the system and how user-friendly it is or isn’t. We were shown that when installed correctly, the system recovers more energy than is needed to run it.
As ever, throughout this course connections were constantly drawn between all the different areas covered (the inescapable interconnectedness of all things!). Nothing stands in isolation; each decision in one area can have repercussions in another. The different elements of building physics and materials must be balanced with each other and with the effect of any action on the wider environment.
The immersive learning environment during module weeks at CAT is highly effective, and very intense. It’s a wonderfully stimulating and supportive place to be, but at the end of the week that intensity needs a release in order for us all to return to our normal lives without winding up our friends and family when we get there. That takes the form of the vitally essential Friday night social, which this month was themed around a Cyfarfod Bach, a laid back Welsh social. We had beautiful music and singing, comedy, artwork, silliness, a rousing rendition of the Welsh National Anthem (not too shabby, considering only a handful of people were Welsh speakers or had any idea how the tune went in advance) and finally a leg-shattering amount of dancing, ensuring we could all go home in physical pain but happily and calmly buzzing.
See more blogs about the MSc Sustainability and Adaptation course.
The sun shines on Mynydd Gorddu Windfarm.
Yesterday the REBE (Renewable Energy and the Built Environment) students were taken to visit Mynydd Gorddu Wind Farm located near Tal-y-bont, Ceredigion, West Wales and given a tour by the site manager. As a media volunteer I get to document all the interesting excursions students make, and so I thanked the weather gods for a sunny day, pulled on my long johns and packed my camera. After bumpy ride down narrow roads on the local coach, we arrived and were greeted by the sites operational manager, a sharp man in his forties. With the sun on our backs, we huddled round like penguins as he explain how this wind farm, which has been successfully running for nearly 20 years was started.
Developed initially by Trydan Gwynt Cyfyngedig in 1997 – a company owned by a local family, Dr Dafydd Huws and Mrs Rhian Huws, npower renewables was involved in the early stages but in 1993 ceased to be involved with the project. Beaufort wind Limited are listed as the owner now, RWE Innogy as the operator. Dr Dafydd Huws had been inspired by the turbines at CAT and later through visits to Denmark where the technology has been developed further. In 1997 however, npower renewables agreed to assume responsibility for the financing and construction of the wind farm. Trydan Gwynt Cyfyngedig became a co-operative venture between npower renewables, now called RWE Innogy and the Huws family company, Amgen, the welsh for “positive change”. Dr Huws and his company Amgen continue to have, a leading role in the development of the wind farm and its operation.
By all accounts this wind farm was remarkably successful, with a good track record of fulfilling its potential, but like all machines they do need maintenance.It was interesting to hear direct from the horses mouth what its like to manage a site such as this, what kind of decisions you have to make when lightening strikes and melts the conductors. Calling crane companies and having to pay them double so they can come lift off the hub and propellers the next day, and get the turbine back in action as quick as possible. These kind of quick financial calculations, mixed in with practical monitoring and maintenance are all part of a days work for a wind farm operational site manager.
The site was awarded European grant of £1.3m to trial four different types of turbine but today there stands 19 turbines, with two different diameters, as the planning authorities weren’t so happy with the idea of too many different machines scattered across the hills. The planners also ensured that the sub-station, where the electricity is sent into the grid and where the turbines are monitored (with P.C’s STILL running from 1995, a little fact to amaze the techo- heads) is built in a true vernacular style, with stone walls, wooden doors and iron detailing.
If you are interested in the performance of these medium sized wind turbines then you may be interested in the following; 7 of the turbines are each rated at 600 kilo Watts with a hub height of 34 metres and a rotor diameter of 43m. The other 12 are rated at 500kW each with a hub height of 35m and rotor diameter of 41m. The rotors on both turbine sizes turn at an approximate speed of 30 revolutions per minute (rpm), driving a gearbox within the nacelle which is in turn connected to a generator. The turbines start to generate electricity automatically when the wind speed reaches around 11 miles per hour (mph), and achieve maximum output at around 33 mph. They shut down when the wind speed exceeds 56 mph, which is rare. The farm has a combined maximum output of 10.2 megawatts.
I have no pretentions of being an engineer, and so many of these technical details the REBE students were avidly scribbling down passed me by and I tuned into the gentle sound of the blades swooshing above me in the cold winter wind and their majestic white silhouettes cutting into the crisp blue sky, a symbol to me of beauty and hope. I was also noticing the red kites sailing high in the sky, the fresh strong blast of cold wind whipping around my ears and noticed a suprising birds nest above one of the windmills doors at the base.
I am interested in the politics and people behind these endeavours and was intrigued to hear how carefully Dr Dafydd Huws tried to maximize the returns to the community by ensuring the windfarm infrastructure spread across more than one owners land. There is a fund, “Cronfa Eleri” that’s administered by Amgen, who have set up the Cronfra Eleri Advisory Committee, ensuring that people who understand the needs of the community decide how the money is spent to provide the widest community benefit. The fund yields about £10,00 a year and in 2011 the fund helped buy a new heating system for a community centre in Ysgoldy Bethlehem, Llandre, a new shed for the local Talybont nursery, the re-wiring and renovation of the local church in Bontgoch, and towards a new tennis court in conjunction with the Playingfield Society Rhydypennau.
As we wandered back to the coach, we waved good-bye to the beautiful bullocks, (the wind farm was fully integrated with the traditional farming practices of the area, with sheep and cows grazing beneath the turbines) and all looked forward to a delicious lunch awaiting us at CAT. The electricity from the farm traced our steps, passing along a cables supported by wooden poles from Bow street to Machynlleth, carrying clean electricity to the local electricity grid network for use in local homes, schools and businesses. All in all it had been a very successful trip, but lets see what Alexandra King, a REBE student who came too had to say;
Who are you and what do you do when your not studying at CAT?
“I’m Alexandra King. I live and work in Bath. My husband is a consulting engineer, I work with him, mainly as a support at the moment, but hope that after finishing this course, I will be more involved in the engineering design.”
Why did you decide to study at CAT?
“CAT is the obvious choice – to my knowledge it is the best place in the country to study renewables. Why? For a long time now I was a mecologist by choice. I believe in sustainable lifestyle. We’ve installed PVs on our roof as soon as we had a chance. Renewable energy is clean and available everywhere, even in the most remote locations. It will not run out anytime soon, unlike fossil fuels. And if we start making changes now, by the time we do run out of coal and gas, we should have good enough infrastructure to keep us going. I don’t know if we could slow down the climate change, but there is always hope.”
What did you learn from the trip to the windfarm?
“I’ve always liked wind turbines, and this visit just reinforced this affection. They are so elegant and not at all noisy. The footprint of a turbine is very small. I love the possibility of the double use of land (cattle or crops), turbines scale easily, the construction time is relatively short, unfortunately so is the lifespan of a wind farm. But I am sure we can overcome this in the future.
One more thing, I’ve visited several wind farms and yet to see a single dead bird, yet, driving home a few days ago, saw 8 corpses on the motorway… one of them was a badger, I think, but still.”
How do you find the teaching on the course, and is there anything you would change about your student experience with CAT?
“I love CAT, wouldn’t change a thing. Except I wish I’d started earlier, like several years ago, but never mind now. I think this course is well balanced; it will give me a broad understanding of principles and technologies that will be very useful in my future work.”
Many thanks Alexandra !
Our popular eco-refurbishment course this month brought together a team of people keen to learn about improving buildings in a sustainable way. Some on the course wanted to make improvements to their homes, others were builders taking the course as part of their professional development. The course was led by Nick Parsons, who has worked for over 25 years in renewable energy, sustainable building and eco-retrofit.
This is a really practical course, ideal for anyone who is planning to refurbish an existing building with minimal environmental impact. There were sessions on solid wall insulation, roof insulation, renewable energy, energy efficiency, heat loss, damp, breathability and ecological materials.
The students really appreciated the course:
“Nick was very knowledgable and pragmatic – and he had a great sense of humour!”
“Can I thank yourself and all the staff at CAT for the warm welcome, smiles and hospitality. Everyone enjoyed the Eco Refurb course immensely and I will certainly be looking at additional courses in the future.”
We would like to say a big thank-you to Natural Building Technologies, Recovery Insulation and Clan Insulation, who provided materials for the practical sessions on the Eco Refurbishment course. Thanks also to Green Building Press who donated copies of The Green Building Bible for the students. Being able to experience a range of materials made a real difference.
The course will be run again next year. Keep an eye on the short courses calendar to see when the dates are announced. Other related short courses include Straw Bale Building 6th-10th October 2014, Wind Power Systems 18-23rd November and an Introduction to Permaculture 20th-22nd February 2015.
Ranyl Rhydwen, a lecturer in CAT’s Graduate school of the Environment on the MSc Sustainability and Adaptation in the Built Environment, drills into the science of sea level rises and looks into the future. First posted by Sustain Magazine:
Humanity has already introduced enough CO2 into the atmosphere to raise the earth’s temperature by 4-6°C. This heat is being added at a rate approximately 300 times faster than when the earth’s ice sheets previously melted; past melt rates are therefore likely to provide low and conservative projections for the future. The earth’s remaining ice sheets contain 70 metres of sea level rise; with 40 metres of that being land locked in the East Antarctic Ice sheet that won’t melt unless CO2 reaches levels of >1000ppm. However the remaining 30m from Greenland, Western Antarctic Ice Sheet and the below sea level EAIS have all previously melted away when CO2 concentration levels were only 400-425ppm (April 2014 level 400ppm). A 30 metre sea level rise involves 50% of humanity, nearly all the world’s mega cities and large swathes of prime agricultural land. Sea levels will take thousands of years to fully rise, however 20 metres is inevitable and 30 metres probable. This needs planning for now as any manmade barrier is very unlikely to be able to cope with a 5 metre rise.
How fast will the melt occur?
Melt rates of up to 4 metres per century have previously occurred and although it is felt it would take the collapse of a major ice sheet to induce this 4 metre rate again, 1-2 metres per century is common, making the IPCC 80 cm projection by 2100 misguided considering the stakes involved. The 4m melt pulses occur due to the collapse of the marine based ice sheets. These ice sheets melt slowly at first as the glaciers get snagged on ocean bed ridges but once free of these ridges, they suddenly (after 200-1000 years) collapse in a process called rapid irreversible marine instability. These ice sheets are particularly vulnerable as they are melted from below by warm deep ocean waters lubricating the glacial flow and due to ocean dynamics warm waters (~3.5°C) currently bathe most of Greenland’s and Antarctica’s marine outlet glaciers.
The discovery that the Amundsen Sea outlet sea glaciers (that drain a third of the WAIS equivalent to 1.2 metres of sea level rise) have developed marine instability (i.e. they will now completely melt away) and are melting at an accelerating rate (30% greater than just 5 years ago) makes 4 metres a century look much more probable. Models suggest that this collapse is irreversible but may take 200-1000 years, however they didn’t account for the inevitable further warming of the melting waters. The last time Greenland, WAIS and parts of EAIS melted (120,000 years ago) melt rates of approximately 2 metres sea level rise per century occurred. The recent finding that the marine based glaciers draining the North East of Greenland (16% of it) have suddenly started rapidly melting and that the Fjords draining Greenland are much wider and extend further inland than previously thought all means that 4 metres in a century is again more likely. Therefore the recent evidence suggests that although 30 metres is the final outcome it is unlikely to occur by 2100, however 1-2 metres is virtually certain, 4-5 metres probable and greater amounts can’t be excluded.
Thus a large proportion of humanity is under direct threat from this sea level rise. The USA military are planning tactical retreat, however moving an army base is not moving a city (London), a state (Florida) or a country (Bangladesh). The first step in adapting to sea level rise is to slow it down and reduce its magnitude and the only way to do that is to remove (bio-sequester) carbon from the atmosphere and getting to 350ppm still means a 20-25 metre sea level rise and require a massive increase in mitigation efforts, which will take a transformation of societal systems to achieve. Adaptation and mitigation therefore need to be considered together. Adapting to sea level rise will mean more than building a sea wall as concrete barriers will have large carbon costs and will be overtopped eventually putting future generations at greater risk.
It seems we need to think again and take the approach of planned retreat, combined with innovative developments that embed humanity’s community into the new ecosystems and create new settlements that are robust to the extreme weather whilst sequestering carbon into the materials used to create them. That radical approach will take a transformation scale of change and the widespread uptake of progressive adaptation planning and is why here at Centre for Alternative Technology, we are putting transformational adaptation into the heart of our sustainability learning and teachings to help understand how to creatively approach the task that sea level rise imposes.
So, we already know why we don’t need fracking, but there are very good reasons for saying we quite simply can’t have it.
“Shale gas is categorically not compatible with the UK’s obligation to make its fair contribution to avoiding the 2°C characterisation of dangerous climate change – the maths on this are clear and unambiguous.”
– We really can’t sum it up any better than this comment from Kevin Anderson, a professor of energy and climate change at the University of Manchester and ex-director of the Tyndall Centre, the UK’s leading academic climate change research organisation.
But others have said it too:
“The world should not be searching for new sources of fossil fuel. We can’t even burn all of what we already have. We need to keep the coal, oil and the gas in the ground” says Simon Bullock (of Friends of the Earth) on releasing a report on ‘unburnable carbon’ last year.
The Carbon Tracker initiative, looking at fossil fuel reserves already listed by the top 200 coal, oil and gas companies on the stock exchange, state that “just the listed proportion of reserves in the next 40 years is enough to take us beyond 2°C of global warming.” And that these are just 27% of known conventional fossil fuel reserves, not including those from most unconventional sources like fracking.
Economist Dieter Helm sums up the issue: “The problem is that we have too much fossil-fuel resource, not too little – enough to fry the planet several times over.”
Budgeting our carbon
Kevin Anderson explains what the problem is, when commenting on the shale gas report released recently by the House of Lords: “Climate change is a cumulative issue – it is about the build up of carbon dioxide in the atmosphere. The 2°C threshold between dangerous and acceptable climate change comes with a carbon budget; i.e. how much CO2 we can emit into the atmosphere.”
The global carbon budget is pretty well defined (here, in the most recent IPCC report see details on ‘cumulative carbon emissions’ (see page 27), and a useful explanation here). We can say what chance we have of avoiding that 2°C threshold given the amount of carbon we release into the atmosphere in total – cumulatively. The less carbon we release, the higher our chances of avoiding ‘dangerous’ climate change.
But how we share the global carbon budget out amongst countries is a little more tricky. One way to do it would be to say each person in the world gets the same share, starting now, which means a country’s allocation would just be based on its population. But this doesn’t take account of the fact that people in the UK have benefited from being a high emitter in the past . Since most emissions remain in the atmosphere for hundreds of years, a substantial amount of what is now in the atmosphere is ‘ours’. We can choose to divide the global carbon budget into countries’ shares from different dates – the earlier the date we divide it up, the more responsibility we take for emitting more than our fair share historically.
The chart shows some examples of this:
Figure 1: Comparison between UK’s share of the global carbon budget for different chances of avoiding a 2oC global average temperature rise (orange; red) and the emissions associated with burning various known fossil fuel reserves in the UK (grey, blue). Note: These figures are are calculated excluding emissions from international aviation and shipping, and are in gigatonnes carbon-dioxide (GtCO2), to make data comparable to those for fossil fuel reserves. They do not, for example, include methane (CH4) that may be released in extraction or distribution of gas. in Zero Carbon Britain: Rethinking the Future, conventionally we use gigatonnes carbon-dioxide-equivalent (GtCO2e) which encompasses all greenhouse gases. For this reason, the budgets used here do not appear the same as those in the latest ZCB report.
The figure above shows exactly what the problem is for the UK – comparing various potential ‘carbon budgets’ to our remaining and potential fossil fuel reserves (both conventional and unconventional). We can see that with a decent (80%) chance of avoiding 2°C, and taking historical responsibility for our emissions back to just 2000 would mean that burning even those conventional fossil fuels projected by UK government would take us way over the 0.4 GtCO2 budget.
If we relax our morals and take almost no historical responsibility, we still can’t burn everything we plan to before blowing our larger budget of 3.4 GtCO2.
In fact, even with a 50/50 chance – which is no better than flipping a coin to see if we will avoid 2°C, and taking almost no responsibility for our actions in the past (bringing our budget to 8.2 GtCO2), we still can’t burn all of the potential conventional fossil fuel reserves in the UK. In fact, Carbon Tracker states in its report “London currently has 105.5 GtCO2 of fossil fuel reserves listed on its exchange”, and that “just one of the largest companies listed in London, such as Shell, BP or Xstrata, has enough reserves to use up the UK’s carbon budget to 2050”
And thats before we even start talking about carbon from unconventional fossil fuels like shale gas from fracking.
Friends of the Earth say “The UK plans on producing far more than a reasonable share of the world’s burnable carbon. Shale gas is just adding to a huge unburnable carbon problem.“
And they’re totally right – no carbon budget for the UK which holds any moral, or ethical sway stretches far enough to be able to start getting at unconventional fossil fuels like those from fracking.
The lesser of two evils?
But isn’t gas better than coal from a carbon perspective? Shouldn’t we be fracking for gas so we can get rid of coal power stations? What about gas as a ‘bridging’, or ‘transition’ fuel to a renewable future?
Professor David MacKay’s report on shale gas for the UK government Department of Energy and Climate Change (DECC), reiterated in evidence he submitted to the Committee preparing the Lords’ report (see pages 353-4), states that “If a country brings any additional fossil fuel reserve into production, then in the absence of strong climate policies, we believe it is likely that this production would increase cumulative emissions in the long run. This increase would work against global efforts on climate change.”
Shale gas, like any other fossil fuel, emits carbon dioxide into the air when burnt to produce energy. As such, Anderson comments, “In that regard it is certainly not a transition fuel and if we are serious about our explicit climate change commitments the only appropriate place for shale gas remains deep underground.“
A better option
It simple: as Bullock states: “The UK should call a halt to new oil, gas and shale gas exploration, and invest in energy efficiency and renewable power instead.” We know this works, and we know we will, regardless of what carbon budget we stick to, have to transition to a zero-carbon and carbon-neutral energy system like that outlined in CAT’s Zero Carbon Britain: Rethinking the Future. We show that we have all the technology we need already, and transforming our society in this way, without fracking for gas, gives us the best chance possible of avoiding that 2oC threshold.
CAT’s course in Renewable Energy and the Built Environment teaches the real solutions for eliminating greenhouse gases from our energy system. Apply now to start in September.
A clear success story for UK wind power this December, re-establishing its potential as a powerful force in the UK .
The future looks promising for the growth of wind power thanks to bad weather conditions and howling wind. Overall, a total of over 2.8m MWh of electricity was provided to the National Grid over the course of the month, enough to power more than 5.7 million UK homes. Moreover, wind power met 10% of total electricity demand during December. The greatest triumph of the day however was on the 21st of December, the busiest shopping time of the year, when wind turbines swung into action and generated 132,812 MWh – thats 17% of the nation’s total energy demand in one day!
Predicted targets for a wide range of reforms that could drive more than £100 billion of investment in clean energy infrastructure such as onshore and offshore wind farms are being realised. It has also come at a crucial time for the Energy Bill that came through last year, as it encourages a secure supply of low carbon electricity generation.
Maf Smith, Deputy Chief Executive of RenewableUK said: ‘This is a towering achievement for the British wind energy industry. It provides cast-iron proof that the direction of travel away from dirty fossil fuels to clean renewable sources is unstoppable… British wind energy is providing a better alternative – a stable, secure cost-effective supply of home-grown power.’
The statistics represent the amount of electricity generated by the National Grid, therefore figures are even higher when taking into account the off grid wind farms and small scale generation.
We had a great visit from the Steiner Academy in Hereford today.
With a strong focus on teaching for sustainability, the school practices what it preaches by generating its own electricity on-site using photovoltaic panels. They also have a wood chip boiler for under-floor heating in the classrooms. Core to the school’s ethos is bringing nature into the classroom, supporting creativity in students and promoting respect.
During a tour of the CAT site by Ann, a member of our Education Team, the students interacted with our on-site displays. The students, who are currently doing their GCSEs, said that ‘they enjoyed the site very much’ and the willow sculptures on-site reminded them of their own school. Some students said they found ‘the mole hole a little bit scary’ but thought it was ‘very creative and artistic’.
Visit our Education Centre to find out more about what CAT can offer to school groups.
Coal use for electricity production today
Currently in the UK, around 80% of all our annual greenhouse gas emissions come from producing and using energy. Burning coal, gas and oil emits carbon dioxide (CO2) and contributes to climate change. Together, these fuels provide around 90% of the UK’s primary energy supply. Some of these fossil fuels are used directly – petrol and diesel (oil) in our vehicles for example; but some are burnt to produce the electricity we use. Although the burning of coal in fires to heat our homes directly has reduced dramatically over recent decades, we still rely on it to produce most of our electricity by burning it in power stations. If we are to play our part in tackling climate change in the UK, and reduce our greenhouse gas emissions swiftly and sharply, it is clear that our methods of energy production must change. There are many ‘lower carbon’, ‘carbon neutral’ and even ‘zero carbon’ methods of energy production that offer us better ways of producing energy, (especially electricity) in the UK.
Replacing or changing coal use in the UK?
In Zero Carbon Britain: Rethinking the Future (the report launched in July 2013 by the Zero Carbon Britain project at CAT), we opt for 100% renewable energy production – wind (onshore, and offshore), solar, hydro, geothermal, wave, tidal, and others – all ‘zero carbon’ or ‘carbon neutral’. With these, and ‘carbon neutral’ synthetic fuels, we can produce enough energy for the UK at the right times – making sure our energy demands are met at all times. In the UK today, however, high on the energy agenda is the conversion of our current coal plants to biomass (see article here about why this is a bad idea), but also about fitting current coal power stations with ‘Carbon Capture and Storage’ (CCS) systems. In these plants, coal is still burnt to produce electricity, and most (but not all) of the carbon dioxide emitted is ‘captured’ before it gets into the atmosphere, and then ‘stored’, usually in old oil and gas fields under the sea or underground. This means electricity made from coal plants fitted with CCS can be classed as a ‘lower carbon’ energy source. So, why then, was there outrage from campaigners and environmentalists at the recent COP19 summit – the UNFCCC international negotiation on climate change – when the International Coal and Climate Change summit took place in Warsaw at the same time? Especially since the World Coal Association stated that the coal summit was meant as a contribution, not an alternative, to the UN talks? And why don’t we include coal and CCS in our Zero Carbon Britain scenario?
What is wrong with coal and CCS?
First of all, current standard methods of producing coal, for example mountain top removal for open cast coal mining, are extremely destructive locally and can be very dangerous. Also, coal (or any fossil fuel) power coupled with CCS does not provide a solution in the longer term. There are limits to the CO2 storage capacity of old oil and gas fields, meaning that in the longer-term they would have to be phased out entirely, and replaced by other energy production systems. Whilst it might seem sensible, or cost-effective to use the current infrastructure we have for burning coal, and simply add CCS, it is likely that this will raise the cost of coal-generated electricity, and increase the requirement for energy by at least 20%. We would have to produce far more energy to make CCS systems work, increasing our demand, potentially for coal itself. Furthermore, storage locations for the carbon captured through CCS, must be monitored indefinitely to minimise leakage. We would need to continually pay to keep the carbon safely locked away. This implies unknown costs and effective risk management long into the future, which cannot be guaranteed. And will it really be safely locked away? Whilst abrupt gas leakage events might be seriously damaging to local eco-systems (especially if the storage is underwater), diffuse leaks can be more difficult to stop and would, at least in part, reverse the effect of capturing the carbon dioxide in the first place, making it questionable whether or not coal and CCS would really provide the carbon reductions it promises.
Electricity is easy with renewables!
Finally, the thing that strikes us most when creating our Zero Carbon Britain scenario is that electricity – what we currently use coal to produce – is what is produced by almost all renewable sources – wind, wave, hydro, solar PV. It’s easy to produce plenty of electricity from renewables, and its much more efficient than burning coal where lots of energy is lost in the conversion process. In fact, given all the estimated resources in the UK, Zero Carbon Britain research suggests we can produce much more electricity than we require from renewable sources – even if we electrify lots of our systems like transport and heating. So, since not all the greenhouse gas (or carbon dioxide) emissions are captured from an electricity-producing coal plant, even when fitted with CCS, why opt for an electricity production method that is only ‘lower carbon’ (and is less efficient) when there are so many options that are more efficient, and truly ‘zero carbon’? Renewable electricity generation technologies offer larger and more secure greenhouse gas emission reductions. They will last us long into the future, provide jobs, and would allow us to be in control of our own energy production. The UK is blessed with great renewable resources – we are located in one of the windiest places in the world – and our future energy system should play to these strengths.