photo: Creative Commons / Genghiskhanviet

Given the UK’s commitment to carbon dioxide emission reductions and the global agreement to limit warming to 2°C, do we need to spend time, money and energy exploring for more oil and gas to extract from the North Sea? If the limits imposed by the Earth system and our political system’s response establish a total amount of future emissions, isn’t it quite likely that existing, already discovered reserves of fossil fuels are more than sufficient? If in fact it would be very unwise to burn all the current reserves, why bother looking for more? George Monbiot made a similar point as the Government were approving new coal mines: Leave It In The Ground

It strikes me as odd, that neither the press release nor any of the other documentation associated with this new licensing phase even mentions the carbon dioxide emissions associated with the production and inevitable combustion of the newly discovered oil and gas they are hoping for. This omission leaves DECC looking schizophrenic, with one hand attempting to meet onerous emission reductions whilst the other simultaneously desperately scratches out the last remaining fossil fuels available.

In April last year I spent two weeks in Lincolnshire with Alf and Teresa Webb at The Bike Inn completing my City & Guild’s qualifications in Cycle Mechanics.

Two weeks at The Bike Inn, Lincolnshire

City & Guilds Level 1& 2 Cycle Mechanics (3902) and The Bike Inn ‘Certificate of Attainment’

Since completing the training I’ve been working with Ross Taylor of Taylored Cycles offering the award winning Bristol University Cycle Surgery to staff and students and volunteering with The Bristol Bike Project.

Bristol University Cycle Surgery

The Bristol Bike Project also won an award. We won the Grassroots category of the 2011 Observer Ethical Awards and here’s the video:

This year I’m venturing into the world of frame building, with a one week course, again in Lincolnshire with Dave Yates and another with the soon to be opened Bicycle Academy. I say soon to be opened as they are currently setting up their workshop following a fantastically successfully crowd funding. They succeeded in raising over £40,000 in under a week though the new peoplefund.it project.

Watch this space for my adventures in frame building!

Hat tip, James, Bristol Bike Project

The pathway tool I like and I would encourage anyone interested in the UK’s future energy system and associated carbon emissions to have a play with it. All I would say is that, like many scenario analyses, it is too narrow. The whole point of carrying out scenario analysis is to explore the possibility space. The DECC tool assumes both population and GDP growth. These parameters may be “out of the scope of consideration”, but I would have liked the energy and emissions tool to allow the exploration of steady-state and also economic contraction scenarios. I got the impression MacKay would also have liked to include this flexibility but he said Westminster wouldn’t allow it.

I did not like his comparison of energy sources though. He promotes the use of a single metric to compare energy sources: power density. This means the amount of power delivered per unit area, expressed in watts per square meter [W/m²]. The lecture focused on wind and nuclear power but the analysis can be done for solar power, energy crops, or fossil fuelled power stations.

The headline results were that wind has a power density of 2.5 W/m² whereas nuclear delivers 1000 W/m². Sounds good for nuclear and not so good for wind! But the difficulty is that MacKay is comparing apples and oranges.

In order to compare things quantitatively as MacKay is attempting to, it helps if units are the same. MacKay’s m² of wind farm are not the same as his m² of nuclear power station. There are three main problems with this analysis:

• Layering
• Time
• Externalities

Layering

Cows in a wind farm

Time
MacKay made no allowance for the time dimension. He just divided the power of a wind farm or power station by its area. This fails to consider that the nuclear power station took at least 10 years to build before its ~40 year generating lifespan, followed by a ~100 year decommissioning period. In contrast, the wind turbines are generating within months of build commencing and decommission can be similarly swift. This results in the nuclear power station using up the land for around three times longer than the period of time it is generating for, which effectively reduces its power per unit area by a factor of three.

Externalities
MacKay also made no allowance for the land requirements outside the perimeter fence of ether the nuclear power station or wind farm. This discounts the land required for the uranium mine, the uranium processing, the water required for cooling and importantly the waste storage. The wind turbines also required an iron ore mine, steel foundry and factory. I am not able to quantify the differences in land requirement but I expect the nuclear power station’s “invisible footprint” to be larger, especially when multiplying up the area used for waste storage by the duration for which the land is required (potentially many thousands of years) as described above. Finally, nuclear power stations have a non-zero probability of catastrophic failure, then requiring exclusion zones of hundreds of km² for decades (Chernobyl, Fukushima).

A Comparable Analysis?
A comparable analysis would consider the fractional land use (layering) of an energy source, the total duration for which this land was used (time) and the land required beyond the immediate installation (externalities). That MacKay’s analysis doesn’t consider these aspects, and that they impact the final results by many factors suggests to me that this metric of comparison is oversimplified. I do not object to the use of the power density metric but would like to see it done properly; otherwise it is comparing apples and oranges and is not useful information.

I don’t doubt that MacKay has considered the points raised above. I am worried that the seemingly-deliberate omission of these factors is presenting an overly political bias towards one source of energy.

According to the above back-of-the-envelope estimates, I would therefore amend MacKay’s comparison of nuclear (1000 W/m²) and wind (2.5 W/m²) to the more realistic 300 W/m² (accounting for time) and 50 W/m² (accounting for layering). These adjustments reduce the difference between nuclear and wind from 400- to 6-fold. A further unquantified adjustment to account for externalities is likely to reduce this still further.

Of course, in the final analysis the total land area that is needed is reflected by the naive energy densities MacKay calculates – to generate most of our power from wind (or solar, or biomass) would indeed require vast proportions of the countryside or sea surface to be utilised, and this is an important consideration. However, given the above considerations, it is clear that the headline numbers MacKay is promoting are unfair to renewables, and overly generous towards nuclear.

Today I’ve come across Coalition of the Willing, a fantastic little film about addressing climate change without the illusive unanimous agreement between governments.

Coalition Of The Willing from coalitionfilm on Vimeo.

‘Coalition of the Willing’ is a collaborative animated film and web-based event about an online war against global warming in a ‘post Copenhagen’ world.

‘Coalition of the Willing’ has been Directed and produced by Knife Party, written by Tim Rayner and crafted by a network of 24 artists from around the world using varied and eclectic film making techniques. Collaborators include some of the world’s top moving image talent, such as Decoy, World Leaders and Parasol Island.

The film offers a response to the major problem of our time: how to galvanize and enlist the global publics in the fight against global warming. This optimistic and principled film explores how we could use new Internet technologies to leverage the powers of activists, experts, and ordinary citizens in collaborative ventures to combat climate change. Through analyses of swarm activity and social revolution, ‘Coalition of the Willing’ makes a compelling case for the new online activism and explains how to hand the fight against global warming to the people.

To find out all about the project and to join our Facebook page, follow us on Twitter, or get the iPhone App visit:
http://coalitionofthewilling.org.uk/

The UK Department of Energy and Climate Change (DECC) published their quarterly Energy Trends document last week. It covers up to the first quarter 2010. The key points:

• Total energy production in Q1 2010 was 6.5% lower than in the first quarter of 2009.
• Oil production fell by 6% compared to the first quarter of 2009.
• Natural gas production was 9% lower compared with the first quarter of 2009. The UK was a net importer of gas in the first quarter of 2010 by 155 TWh compared with 106 TWh in the first quarter of 2009.
• Coal production was 12.5% lower than a year earlier.
• Nuclear’s supply increased by 1% on the first quarter of 2009.
• Wind, hydro and other renewables supplied 6.5% less electricity than in the same period last year, with hydro down 44% as a result of less rainfall.
• Final energy consumption rose by 4% between the first quarter of 2009 and the first quarter of 2010, with rises in all sectors except transport which fell mainly due to the adverse weather conditions.
• Gas demand was 13% higher than a year earlier.
• Electricity consumption was 2.5% higher in the first quarter of 2010 compared to the same period last year.

It’s a familiar story: every year the UK’s primary energy production declines significantly. Today, primary energy production is almost half what it was at the peak just a decade ago. Has any other country, let alone major economy experienced such a speed and magnitude shift in its energy system outside wartime?

The rises in the demand data above are largely due to the colder winter and a degree of recovery from the recession. One could argue the decline in indigenous production played a role in the recession. If it did, I suggest it was a small role.

Data from DUKES 1.1-1.3.

The annual energy deficit in 2008 was 57.5 million tonnes of oil equivalent (mtoe). That’s a lot of energy to import. The breakdown of this deficit in 2008 was 42% coal, 36% gas and 19% oil. Let’s just make a quick estimation on how much this is costing:

In 2008 the gap cost the UK approximately £10 bn. Fuel prices were a little lower in 2009 (especially coal and gas at -17% and -15% respectively) and the recession closed the gap from 57.5 to 53 mtoe. A few years ago the energy sector was a net source of income for the UK. No longer. The government deficit and the growing debt is receiving the media attention, this energy deficit, now it its fifth year remains largely ignored.

Following the May election, the UK now has a new Energy Minister:

Chris Huhne MP, Secretary of State for Energy and Climate Change.

On the 24 June 2010, Huhne gave a speech to the Economist UK Energy Summit, it can be watched here: VIDEO

Did he address the chart above, our energy deficit in the same way chancellor George Osborne had addressed the fiscal deficit in his emergency budget earlier in the week? Well no, not directly. Economic recovery, energy security and climate stabilisation were identified as the key challenges. He isn’t a politician to question growth but did address the type of growth. “…dependence on fossil fuel would be folly. It would make us vulnerable to oil price spikes and volatility.” He called for a decarbonised economy stimulating growth and delivering on climate change and energy security. Sounds good but surely it is having one’s cake and eating it?

After stressing the urgency and seriousness of climate change Huhne addressed energy security. “It is vital we make the most of our domestic oil and gas assets…” indicating at least 20 billion barrels oil equivalent remain in UK waters and that we must continue to invest in exploration. His first mutually exclusive objective of delivering growth through decarbonising is now joined by his second of addressing climate change whist continuing to explore for new fossil fuel resources.

£200 bn of energy investment was said to be needed over the next decade, largely to replace existing assets. On new nuclear, Huhne stressed it will go ahead, but only if it can do so with no public subsidy. In my opinion this all but rules out nuclear as there is little precedent for wholly privately funded nuclear, but we shall have to wait and see. Whatever happens, it will be late with respect to the decommissioning schedule of the existing fleet of nuclear power stations.

Efficiency was described as the fourth energy resource (relegating nuclear and renewables to 5th and 6th?)–the cheapest way of closing the energy gap between demand and supply – “the Cinderella of the energy ball”. Smart meters and grids received a nod but he focused mainly on the existing aged housing stock. “Most of the homes in use in 2050 have already been built … we used more energy heating our homes than Sweden, where average January temperatures are 7 degrees Celsius lower than ours.” Addressing existing homes will be Huhne’s flagship programme. He’s talking about insulating millions of homes. It seems the improvements will be funded at least in part through the energy savings and recovered directly from household utility bills.

“The era of cheap energy is over. …tomorrow’s energy bills will undoubtedly be higher”

When asked about the lights going out, he ruled out wind and nuclear coming to the rescue due to the timeframe, but he stated gas fired power stations can be built in 18 months and assured us the lights wouldn’t go out on his watch. Carbon capture and storage (CCS) was described as vital to meeting climate objectives whilst keeping the lights on.

So in summary, Huhne didn’t address the fundamental peaking of energy supplies which surely should be the key driver for national energy policy today. The inconsistencies of shooting for growth whilst reducing energy use along with addressing climate change (by which I can only assume he means reducing carbon emissions) while encouraging future exploration for oil and gas are glaring. Meinshausen et. al. showed in their Nature paper last year the world has more than enough proved fossil fuel reserves already from a climate change point of view without having to discover more. His enthusiasm for CCS is also worrisome and I would see as largely incompatible with energy peaking scenarios. His focus on energy efficiency and especially domestic energy use is positive though. However there was no mention of transport at all.

New government, new minister but we still seem little closer to recognising the challenges ahead.

Natural gas is regarded as a relatively environmentally friendly way of generating electricity. Gas burns cleanly without many of the problems associated with coal. Coal is a chemically complex substance. When it is is burnt, it releases oxides of sulphur (SO_x) and nitrogen (NO_x), traces of mercury, selenium and arsenic, as well as particulates, and a non-combustible slag remains after burning. Coal mining is also a dirty and dangerous job.

Coal emits considerably more CO₂ than natural gas per unit energy. However, natural gas (CH₄) itself is a potent greenhouse gas, and its release to the atmosphere without being burnt can quickly compensate for the CO₂ advantage against coal.

Generating electricity from fossil fuels typically involves their combustion in large power stations. Due to the molecular differences of coal, oil and gas, different amounts of carbon dioxide are produced for each unit of thermal energy. For example, the EIA tells us coal (anthracite) releases 227 pounds of CO₂ per million BTU (or 351 g/kWh thermal), fuel oil or diesel 161 lb/MBTU (249 g/kWh) and natural gas releases 115 lb/MBTU (178 g/kWh). This, coupled with the variability in power station thermal efficiency leads to significant variations in the amount of CO₂/kWh of electricity emitted.

The figures below are for the UK electricity grid.

This table was lifted from: http://electricityinfo.org/co2emissions.php

These CO₂ emissions are directly related to the fossil fuel combustion and power station efficiency. Lifecycle emissions are not included, leaving nuclear and renewables at zero, because emissions related to construction, decommissioning, uranium processing etc. are ignored. Natural gas is considered the ‘greener’ fuel as electricity from gas emits 2.5 times less CO₂ than coal, as well dramatically lower CO, NO_x and virtually no SO_x or particulates.

There is an issue of system boundaries here. The figures above only consider the power station and not any upstream supply system. While CH₄ may leak from the gas pipelines, there are also CH₄ releases from coal mines. For this post, let’s consider emissions after the mine mouth or well head, and ignore emissions associated with transporting coal.

For oil and coal, the only significant route into the atmosphere is via combustion. However, besides being burnt, natural gas can be released without combustion as methane, CH₄. This becomes interesting when one considers both the impact of atmospheric emissions of CO₂ and CH₄. Both are greenhouse gases in that they that absorb and emit radiation within the thermal infrared range of the electromagnetic spectrum, however their respective radiative forcings are very different. The radiative forcing measures how much a greenhouse gas (or other factors) alters the balance of incoming and outgoing energy in the Earth-atmosphere system.

The Carbon Dioxide Information Analysis Center (CDIAC) part of the US Dept. of Energy uses Global Warming Potential (GWP), as it provides a simple measure of the radiative effects of emissions of various greenhouse gases, integrated over a specified time horizon and relative to an equal mass of CO₂ emissions. Over a common 100 year time horizon CDIAC state the global warming potential of CH₄ as 25 times greater than CO₂ [link]. The calculation is not trivial, and estimations do vary a little, but for this analysis the factor 25 is sufficient.

We saw above that natural gas emits 2.5 times less CO₂ than coal when used to generate electricity. However, when CH₄ is released to the atmosphere without first being combusted, the global warming potential is 25 times higher than CO₂. It is a more potent greenhouse gas. If only a little natural gas is released without being burnt, it will dominate the radiative forcing and more than compensate for the 2.5-fold advantage gas has over coal.

The chart illustrates this effect:

On the left, CO₂ emissions per kWh for coal and natural gas. On the right, the global warming potential of leaked CH₄ expressed as CO₂

If the natural gas leak rate is 3%, the global warming potential of a kilowatt-hour of electricity from gas is equivalent to coal.

Leak Rates

So what are pipeline leak rates? A 1997 US Environmental Protection Agency report states US methane leak rates were 1.4 +/- 0.5 % in 1992. The largest source of leakage at that time was compressor components used in the processing, transmission, and storage, followed by the distribution network itself, with the small length of old cast iron pipes leaking disproportionately highly. The natural gas production process also contributes through millions of slowly leaking pneumatic control devices. A larger study carried out from 2005 by Brazil’s largest gas distributer Comgas suggests cast iron pipe leak rates double the EPA study.

A 1990 study for Greenpeace considered the UK distribution network then operated by British Gas. Greenpeace estimated low, medium and high scenario leakage rates of 1.9%, 5.3% and 10.8% respectively. This was in contrast to the 1% claimed by British Gas at the time. The authors were confident leakage rates were above 1.9%. These figures are likely obsolete today as there still existed a large amount of pre-1970 cast iron pipe work, much of it since replaced. In 1990 only 39% of the UK mains and 74% of the service pipes were plastic.

The 1.4% figure is also old, and only refers to the US, but it is a significant magnitude, it represents a 70% increase in global warming potential compared to the CO₂ alone and halves the CO₂ advantage gas has over coal based on the 360 and 890 g/kWh figures above.

Whilst these figures do not tip gas beyond coal, they halve its advantage. They are also only national. For the US this is quite understandable, but for the UK and Europe, the gas system is changing. Could leak rates become important as natural gas supply routes become longer? As Europe increases its reliance on Russia, as previously stranded gas is brought to market through longer pipelines than before, as a larger number of smaller deposits are exploited and as existing infrastructure ages, it seems likely that leak rates will increase. We often hear about struggles in the former Soviet states related to gas – is the leak rate there one percent or five? Is it economically feasible for the pipeline operator to make investments to stem the last percentage point of a system’s leaks?

Is it possible that a ‘green’ gas power station in the UK is making a greater contribution to global warming than one burning coal?

Does anyone have recent data on leakage rates, especially for Russia and Eastern Europe?

Further information on HMS Queen Elizabeth is available here: Wikipedia

It’s an interesting coincidence that just as coal was being discussed as a future source of liquid fuel UK production was peaking. The all time peak production rate of UK coal was 1913:

UK Coal Production

UK Coal Production (D. Rutledge)