By Dave Elliott
A recent paper in Applied Energy, from two researchers at Imperial College London, offers some helpful policy and economic insights on the impacts of various UK possible energy mixes for electricity supply, including a high renewables mix, but with biomass use not included, based on detailed spatial (20 regions) and temporal (hourly) modelling. Scenarios with nuclear and fossil/CCS were also explored.
By Margaret Harris in Chicago
The environmental risks of shale-gas production are real, but the things people worry about most aren’t necessarily the ones that cause the most damage. That was the message of this morning’s AAAS symposium on “Hydraulic Fracturing: Science, Technology, Myths and Challenges”, which featured talks on the social implications of hydraulic fracturing as well as the risks of water and air contamination.
Hydraulic fracturing, or “fracking”, involves drilling a well and filling it with a high-pressure mixture of water and other chemicals. These high pressures cause nearby rock formations to fracture, releasing trapped oil and gas. According to the first speaker, energy consultant David Alleman, fracking and horizontal drilling have “revolutionized the energy picture in the US”: a few years ago, the country imported 60% of the oil it consumed, but today the figure is just 30%.
In the 2012 Budget, Chancellor George Osborne said ‘Gas is cheap, has much less carbon than coal and will be the largest single source of our electricity in the coming years’.
DECC followed this up by saying that it saw gas as ‘continuing to play an important part in the energy mix well into and beyond 2030, while meeting our carbon budgets. We do not expect the role of gas to be restricted to providing back-up to renewables, and in the longer term we see an important role for gas with CCS.’
However then the independent advisory Climate Change Committee (CCC) warned the government that ‘Extensive use of unabated gas-fired capacity (i.e. without carbon capture & storage technology) in 2030 and beyond would be incompatible with meeting legislated carbon budgets’.
DECC backed off a bit, saying that ‘after 2030 we expect that gas will only be used as back up [for variable renewables], or fitted with Carbon Capture and Storage technology.’
There are all sorts of problems with this plan. Firstly, it is far from clear whether, and if so when, CCS technology will be available and widely deployed. What is clear is that it will add substantially to the cost of power generation. Secondly, it is not clear to what extent shale gas will extend the UK’s diminishing gas reserves- and at what price, in both economic and environmental terms, not least given the large amounts of water needed for fraking, the resultant ground water contamination and the risk of micro-quakes from fraking. Thirdly, pushing ahead with CCS and shale gas will deflect resources from the development of renewables, including sources of green gas (see my previous Blog), the only real long term sustainable energy options, unless you see fast breeders or fusion as viable, sustainable options.
All these issues are contentious. The industry say that shale gas fracking is fine, with minimal environmental impacts: http://www.cuadrillaresources.com/what-we-do/hydraulic-fracturing/history/
However, the European Commission has published a study on environmental impacts which says that extracting shale gas generally imposes a larger environmental footprint than conventional gas development. Risks of surface and ground water contamination, water resource depletion, air and noise emissions, land take, disturbance to biodiversity and impacts related to traffic are deemed to be high in the case of cumulative projects. On climate impacts, the EU has issued a report which says that shale gas produced in the EU causes more GHG emissions than conventional natural gas produced in the EU, although, if well managed, less than imported gas from outside the EU, whether via pipeline or by LNG, due to the impacts on emissions from long-distance gas transport. [http://ec.europa.eu/environment/integration/energy/unconventional_en.htm
Some see emissions from shale gas combustion being abated by CCS. However, some environmentalist worry about the impacts and safety of CCS (e.g. the risk of sudden major CO2 release) and about it providing a way for the continued use of fossil fuels at high extra cost, with, in practice, the net emission reductions not actually being as high (80-90%) as is claimed.
The European Environment Agency says that, depending on the CO2 capture technology used, there could be a net rise in some toxic emissions: www.eea.europa.eu/publications/carbon-capture-and-storage
Some studies also suggest that CCS might trigger, and be susceptible to, micro-quakes, possibly releasing all the stored CO2 suddenly: http://m.technologyreview.com/energy/40638/(http://m.technologyreview.com/energy/40638) and www.pnas.org/content/109/26/10164.short
However, CCS does offer the possibility of carbon negative energy production, if carbon neutral biomass is used as a fuel, so some greens see fossil CCS as an interim test bed for a very positive green CCS option.
Against that, there are the opportunity cost issues both for CCS and shale gas. They both keep fossil fuel going as major option. It does seem that shale gas has already undermined renewables in the USA: http://www.foodandwaterwatch.org/blogs/memo-to-fracking-apologists-youre-hurting-renewables-and-youre-greenwashing-too/
Certainly there has been a boom in shale gas there. The U.S. used to generate about half its electricity from coal, and roughly 20 % from gas. But now coal’s share is 32%, on a par with gas, with shale gas paying an increasing role. There are disputes about net emission from shale gas, but natural gas is about 40% less carbon intense/kWh than coal, and the overall result of the US ‘dash for gas’ is that emission have fallen by 14%, although the expansion of wind power will also have helped. But will shale gas boom continue? Some say the wells will become rapidly depleted: http://www.huffingtonpost.com/brendan-demelle/fracking-output_b_1900810.html
In the UK, the optimists suggest that shale gas finds so far could be worth up to £50 bn and were equivalent to about a third of conventional UK natural gas reserves- and much more may be found to be available. www.eua.org.uk/sites/default/files/Gas%20Security%20of%20Supply%20-%20Policy%20statement.pdf
A much better option, some say, than importing LNG from Qatar, or expanding coal use. The later is more carbon intense, the former may be unreliable: http://www.cnbc.com/id/49328328
So the battle goes on, with a series of reports reviewing the prospects from a range of perspectives, e.g :
On (or rather under) the ground, some shale gas drilling looks set to go ahead in the UK, but although there are plans, as yet there are no major UK CCS projects. There was much vilification about the mess, following the collapse of the earlier CCS programme. Margaret Hodge, chair of the Public Accounts Committee, commented that the government ‘must learn the lessons from this failure to avoid squandering any more time and money’. The National Audit Office published a review of the programme, which said the failed funding round was ‘a high-risk and challenging undertaking launched with insufficient planning and recognition of the commercial risks’. A UKERC report talked of a long hard trek. http://www.ukerc.ac.uk/support/tiki-read_article.php?articleId=1881
The government has launched a new funding programme, with a view to starting commercial operations in the 2020s, using the £1 bn from the shelved CCS programme. The original programme had been about CCS for coal-fired plants, but it has now been expanded to gas plants. That’s maybe just as well. For, with OFGEMs concerns about power shortfalls hitting the headlines, 20GW of new gas-fired plant have been proposed for installation by 2030. Though whether any of this will have CCS remains unclear. As is also how much shale gas there will be to run them on- despite the Chancellors promise of a ‘generous tax regime’.
While shale gas extraction is new in the UK and is being opposed in parts of the rest of the EU, the situation in the USA is somewhat different. As noted above, shale gas fraking is widespread and expanding. CCS is also now beginning to take off there, although in a more limited way. There have been some small CCS projects in Germany and France, but what has been claimed as the word’s first integrated carbon capture system, a demonstration project in Alabama, has began underground injection of CO2 recovered from emissions from a coal-fired power plant.
For an overview of CCS technology and the evolving regulatory situation in the USA, see ‘Carbon Capture and Storage’ G. Morgan and S, Mccoy, Routledge.
There has been much opposition to shale gas extraction via the new techniques of directional drilling, hydraulic fracturing and pressurised gas collection/release, with dramatic footage of water from domestic taps catching light due to dissolved gas in areas of the US where shale gas ‘fracking’ projects are underway. It certainly makes for powerful videos.
However, some say this is not new and happened long before shale gas extraction started. Maybe so, but there are other eco issues, including ground water contamination with chemicals that are forced deep underground, along with water and sand, to fracture the shale and release its gas. www.bbc.co.uk/news/science-environment-13333473
In addition there’s the shear volume of water need for fracking. Moreover shale gas is still a fossil fuel, so burning it produces CO2- and any leakage from fractured strata could be serious for the climate, since CH4 is a much more powerful greenhouse gas.
The Tyndall Centre has called on the UK government to put a moratorium on shale gas operations in the UK until the environmental implications are fully understood. It was also worried that a rush to exploit shale gas could divert effort away from developing a long-term sustainable low carbon economy. www.tyndall.ac.uk/sites/default/files/coop_shale_gas_ report_final_200111.pdf
Similarly, in a RIIA report ‘The Shale Gas Revolution: hype or reality?’ Paul Stevens, senior research fellow at Chatham House, commented ‘in a world where there is the serious possibility of cheap, relatively clean gas, who will commit large sums of money to expensive pieces of equipment to lower carbon emissions?’
Global shale gas reserves are put at 456 trillion cubic meters compared with 187 trillion cu.m for conventional gas, according to a 2010 World Energy Council report. Over 60% of shale gas deposits are in North America and Russia. Stevens says producing shale gas using horizontal ‘fracking’ costs $3 or less per million British thermal units whereas it’s said that conventional gas drilling cost about $10 per million Btu.
So what hope is there for renewables- until shale gas runs out? But there are some uncertainties about whether the shale gas revolution will be as big as some predict, and Stevens says ‘if it fails to deliver on current expectations- and we will not be sure of this for some time- then in ten years or so gas supplies will face serious constraints’. [www.chathamhouse.org.uk/files/17317_r_0910stevens.pdf
Certainly some say the energy costs of extraction may make it counterproductive as the reserves thin out. So there could be a boom and bust scenario.
And the eco costs may be large. A leading critic is Professor Robert Howarth from Cornell University. In a draft paper last year he claimed that hydraulic fracturing may contribute significantly to greenhouse gas (GHG) emissions. He said that there were significant GHG emissions from the well-drilling, water-trucking, pipeline-laying, and associated forest- felling. Combining the effects of combustion, production, distribution, and leaked methane gives the fuel about the same GHG emissions as coal- 33 grams of CO2, compared to 31.9 grams for coal.
The analysis was partly based on a methane leakage estimate of 1.5% of natural gas consumed, a figure assumed by the federal government, methane of course having much more climate impact per gram than CO2. Although he admitted that it was only a preliminary assessment,. it drew fire from the America’s Natural Gas Alliance, who dismissed his assertions as ‘preliminary and speculative and not backed by hard data’. It added ‘Natural gas is twice as clean as coal and is available here in America in significant abundance today. Alongside the development of renewables, natural gas has a key role to play in transitioning our nation to a low-carbon economy.’
Howarth attracted similar criticisms when earlier this year, more of his results were widely quoted: in a new paper he claimed that generating electricity from shale gas produces at least as much climate impact as coal-fired power, and perhaps more. [www.eeb.cornell.edu/howarth/Howarth%20et%20al%20%202011.pdf
To make sensible comparisons you have to take account of the fact that methane’s residence time in the atmosphere is much less than that for CO2, but Howarth did offer data for both 20 years and 100 years. ‘Compared to coal, the footprint of shale gas is at least 20% greater and perhaps more than twice as great on the 20-year horizon, and is comparable over 100 years’.
Howarth has articulated what seems to be a common US view: ‘My strong belief is that shale gas has been promoted far beyond the objective evidence of what it can and cannot do. It is time to step back, and objectively analyse whether this is a reasonable energy technology for our future. It is also time to analyse how environmental issues associated with the technology might be reduced, and at what cost.’
Some US cities including New York and Pittsburg are trying to halt local drilling for shale gas, with Philadelphia calling for at least a temporary ban on new wells in the watershed that serves the city. There have also been concerns in Texas. See: www.chron.com/disp/story.mpl/editorial/7412406.html
Fracking in the EU
So far it’s mainly been a N. American issue. But successes in the USA have led to prospecting across Europe. A report by IHS CERA said that unconventional gas reserves, including shale gas, in Europe could total 173 trillion cubic metres. Interestingly, France imposed an interim moratorium on shale gas extraction earlier this year, and may ban it entirely, after the government backed a draft bill that would outlaw the controversial process.
It’s estimated that the UK could meet around 10% of its current gas needs from shale gas, if it can be extracted at a commercial rate. And with exploratory drilling starting last year in Lancashire, the Energy and Climate Change Select Committee has been looking into its implications for the UK. The results should emerge soon, but in its evidence to the Select Committee, Scottish and Southern Electricity plc said that, while shale gas was a viable if relatively small option for the UK (compared to the US), ‘there is a concern that with limited capital for investment in the energy industry, significant development of policy incentives to encourage development of shale gas resources in the UK, alongside uncontrolled growth in gas-fired generation could decrease investor certainty on UK policy direction towards renewables, CCS and/ or nuclear. Although this would lead to a short-term gain in carbon emission reductions, it would be to the detriment of the long-term decarbonisation of the UK power sector’.
All the submissions are at: www.publications.parliament.uk/pa/cm201011/cmselect/cmenergy/writev/shale/contents.htm
Most environmental groups have clearly made up their minds. Jenny Banks, climate and energy policy officer at WWF-UK, called on the British government to halt shale gas exploration. ‘It would be ridiculous to encourage shale gas when in reality its greenhouse gas footprint could be as bad as or worse than coal. We need to reject this source of gas, and have a clear plan to move away from our dependency on fossil fuels and harness the full potential of renewable technologies.’
Friends of the Earth offered a quite nuanced view to the Energy and Climate Select Committe: ‘available data suggests that the carbon footprint of shale gas is smaller than that of coal used in electricity production, although it is higher than that of conventional gas. Therefore if shale gas was to displace existing coal electricity generation then there would be a net carbon reduction. However, as some coal is being displaced anyway via the LCPD, new shale gas would more than likely be displacing other types of electricity generation such as renewables’.
However there are other views. For example, a new report from the Global Warming Policy Foundation, which is headed by Lord (Nigel) Lawson, argues that the eco-hazards ‘are much smaller than in competing industries’. It claims that ‘a single shale gas well uses in total about the same amount of water as a golf course uses in three weeks’. Perhaps not the best comparison! It concludes ‘A surge in gas production and use may prove to be both the cheapest and most effective way to hasten the decarbonisation of the world economy, given the cost and land requirements of most renewables’.
The debate continues.
For a good review of EU shale gas developments, see: http://e360.yale.edu/feature/fracking_comes_to_europe_sparking_rising_controversy/2374/