Sunday, August 12, 2007

All the news that's fit to burn

Newspaper Innovation claims that in London every weekday, 400,000 copies of the London Lite and 500,000 copies of The London Paper hit the streets, almost literally as they are discarded on the floor. Have you ever wondered what that flow of newspapers would be worth as a source of energy?

My friend weighed an typical London paper and came up with 100 grammes. So we have just short of 65 tonnes of newspapers per day, every day, on average (i.e. averaging the weekdays over the weekend too).

What is a kilogramme of newspaper worth, in energy terms? Aysen Ucuncu at the Department of Civil and Environmental Engineering at Duke University comes up with a figure of 7540 BTU/lb, or 4.9 kWh/kg. So we can calculate 13 MW of potential thermal power flows onto London's streets, embodied in the carbon bonds of those free newspapers.

What could that potential be worth? Imagine you could collect all the newspapers up, without expending a single Joule of energy in the process, and burn them in a biomass boiler. Let's say you attached the boiler to a generator to make electricity at maybe 27% efficiency and sold it for £32/MWh, a typical long-term contract price for electricity from a waste-to-energy plant in London. You'd get £1m per year, or roughly 0.4 pence/newspaper.

Are the newspapers a significant source of energy? No. Burning them would supply only 0.04% of the average UK primary energy demand per person (13 MW of power over a readership of 7 million Londoners is 0.04 kWh/day/person, while average UK demand is 120 kWh/day/person).

Funnily enough, if you were to ever read one of these papers, it wouldn't be long before you read that you should unplug your mobile phone charger, for the sake of climate and energy security. But leaving a phone charger plugged in these days typically draws less than 1 W of electricity, or less than 0.02 kWh/day. You could generate electricity at more than five times that rate by burning your daily paper in the scheme above. Whether you thought it was worth reading first is up to you. All I can say is unplugging your mobile phone charger isn't going to save the planet.

Tuesday, May 15, 2007

CO2 pollution from nuclear construction is irrelevant

Nuclear power is often cited as part of the solution of a low-carbon future, but detractors sometimes cite the CO2 pollution that would result from the concrete and steel needed for construction as a reason to hold back. While there may be other reasons for holding back, this particular one is spurious.

A way to measure the pollution performance of different energy sources is to divide the amount of CO2 pollution by the energy produced. For fossil fuels, looking at the fuel and not the plant cost (which we assume to be irrelevant), this number is between 300 and 900 g CO2/kWh, depending on whether you use gas, oil or coal, and how efficient your plant is. The CO2 involved with constructing (not operating or decommissioning, mind) is only 1 g CO2/kWh.

The calculation

How much concrete and steel in a nuclear power station? The Nuclear Energy Institute claim ( 400,000 cubic yards (306,000 cubic meters) of concrete and 60,000 tons (67,000 tonnes) of steel in a 1 GW rated nuclear power station. Let's work out how much CO2 this means, then divide by the energy generated over the productive life of the plant.

Notice our input figures are rough, so we're really only looking at one significant figure accuracy.

CO2 from concrete

How much CO2 is produced when making 520,000 cubic meters of concrete? That depends on the kind of concrete. There are different types and different figures. One way - take the density of concrete (2,300 kg/m^3 from the Physics Factbook), the CO2 to make cement (0.8 kg CO2/kg cement), the cement in concrete (10% from This makes a figure of around 100 million kg of CO2 in our nuclear plant.

However, the Danish Technology Institute report ( is probably more authoritative. They claim that a cubic meter of concrete requires the production of 100 kg CO2, giving us 50 million kg of CO2 in our nuclear power station.

Comparing the figures, the order of magnitude matches. To be harsh, though, let's take the bigger figure - 100 million kg of CO2 for the concrete in a 1 GW power station.

CO2 from steel

How much CO2 is produced when 67,000 tonnes of steel is made?

Blue Scope Steel ( claim they put out 14.5 million tonnes of CO2 equivalent gasses in 2004/2005 to produce 5.72 million tonnes of steel product, which suggests around 2.5 kg CO2 per kg of steel. materials suggests around 2 tonnes of CO2 per tonne of steel, and Tata Steel claim ( between 1.2 and 1.9 tonnes of CO2 per tonne of steel, depending on the process.

Let's be harsh again and pick 3 tonnes of CO2 for a tonne of steel. So we have another 200,000 tonnes of CO2 from the steel, or 200 million kg of CO2 from the steel to make a 1 GW nuclear power station.

Sum the steel and concrete CO2 figures: 300 million kg of CO2. If we had been conservative, that would have been 100 million kg CO2.

Energy from a 1 GW nuclear power station

If the power station produces power for a conservative 40 years, and runs for a pathetic 60% of the time (thus we're allowing for maintenance periods), the plant will deliver 210,000 million kWh of electricity.

The ratio is nearly zero

The simple ratio is 300,000,000 kg CO2 / 210,000,000,000 kWh - nearly 0.001 kg CO2 / kWh. Irrelevant.

This ignores the pollution from getting the fuel and running the plant. Also remember the CO2 is largely produced up front, which is bad news for quick CO2 reduction, but even building 10 GW of capacity to replace the UK's ageing plants will only produce 3 million tonnes of CO2 during construction - less than 1% of UK CO2 pollution in one year.

Wednesday, March 28, 2007

How not to support low carbon innovation

Yesterday the Carbon Trust held a debate on how to innovate towards a low carbon economy debates. During the discussion, the need to make money, engage with investors and encourage investment came up. It was suggested that carbon dioxide pollution would be reduced as a welcome by-product of investors' greed. Meanwhile, in the audience we wrung our hands, wondering about how business and the government could encourage innovation with a little investment here or some market intervention there.

Yet there is one clear, simple answer to address this issue. The mother of invention is necessity. The government should foster innovation by regulating the amount of carbon dioxide with which we pollute the atmosphere. The regulation will have to be introduced carefully and will require significant public involvement and education to avoid the cure being worse than the disease. Nevertheless, with a pollution limit in place, there will be no end to our innovation.

Note also we must turn the relationship with investors on its head. Society must first proscribe the requirements, then their inventive and tireless pursuit of the best return on capital can optimise a solution.

Wednesday, February 28, 2007

Smoke and mirrors - a tax on your jet fuel?

A new petition has appeared on the Downing Street website this month urging the Prime Minister to introduce a tax on jet fuel. While no doubt well intentioned, could such a tax make matters worse, if it is not accompanied by comprehensive pollution regulation?

One possible, presumably intended consequence of the tax would be to deter people from flying. Unless the tax is set at a high enough level it is doubtful that it will reduce the amount we fly by any significant amount. How high is high enough? It would be a brave Government which imposed a fuel tax of as much as 100%. Yet fuel costs already rose by more than this in the past four years and flying is as popular as ever. Setting a politically acceptable tax is therefore unlikely to raise the cost of flying to the point where people choose not to fly. For many, as long as alternatives remain relatively costly and slower, flying will remain the popular choice, even with the additional financial burden of a fuel tax. The reality is that people benefit from the ability to fly too much to care about relatively small changes in price.

Worse, there are other, less visible side effects of a fuel tax. Imagine the tax is imposed and the cost of flying goes up a little, perhaps by as much as the difference between booking a few days later on a low-cost airline. You have already decided to fly because there aren't any good alternatives, but you intend to compensate by saving a little elsewhere. Herein lies the second problem.

Squeezing people's purses will drive them away from "green" goods, which are frequently more expensive. The local organic produce starts to lose out to the cheaper, polluting alternatives. That "green" energy provider that is a bit more expensive than the others starts to look less attractive. In this scenario, the fuel tax could have the perverse effect of increasing the pollution rate.

Finally, consider what the government is likely to do with the new tax. Governments like to generate growth. Growth correlates very closely with CO2 pollution. Without some care, the tax could well be spent on growth activities and with a concomitant increase in pollution.

So what is the solution to these unintended consequences? The answer lies in better regulation. The Government ultimately needs to limit the overall level of pollution, capturing all its sources. Without this, otherwise well-meaning pollution initiatives are in danger of back-firing in a cloud of smoke and CO2.

Wednesday, January 31, 2007

Omit the emissions euphemism

The first step to addressing the problem of climate change is to use the correct language - pollution, not emissions. The term pollution is logically correct. Moreover, using it immediately shows up some otherwise well-meaning solutions as false, and it prepares the ground for what is really needed: a regulated cap on acceptable levels of pollution.

Crude oil and CO2 are both natural substances. Both have valuable properties: one powers our society and the other helps plants grow. Both can be deadly: components of crude oil are carcinogenic; fill your lungs with CO2 and you'll suffocate. The distribution of both, in time, can be managed by natural processes. Among the important differences, however, is the following. Whereas crude oil can be naturally broken down relatively quickly (indeed it's likely that the best thing to do with an oil spill is to leave it alone and not spray with chemicals), the rate at which these natural processes work on CO2 is too slow for our current population. This presents a problem of pollution.

Crude oil is not normally pollution. It naturally bubbles up from the ground, albeit in small quantities, in some places of the world. When you put a lot of it into a tanker, you're managing a valuable commodity. However, when the same oil is no longer in the tanker but spilled onto the surface of the sea or shore, it's a liability. Just like industrial solvents that are valuable in the factory but costly when flushed untreated into a river, otherwise precious molecules can be transformed into pollution just by being in the wrong place and in the wrong quantity. Emission is an unacceptable euphemism. In the same context, pollution is the right word to use when talking about our influence of CO2 in the atmosphere.

Accepting this word pollution is the first step towards averting long-term climatic disaster. It clarifies the problem and even helps to immediately assess the relative merit of some candidate solutions.

Would you like a personal CO2 pollution credit, as advocated by the Royal Society of Arts and echoed by the UK government's David Miliband? No. I don't want personal pollution credits for mercury, lead, CFC or SO2 either. I certainly don't want personal pollution credit cards filling up my wallet.

Should CO2 pollution be regulated? Yes. Should CO2 pollution be regulated at source? Yes. It is conveniently easy to identify the source of the pollution. Oil and gas wells, coal mines and cement factories are difficult to hide, both financially and physically. You could even use Google Earth to help.

As consumers, we must do what we always do and make our choices based on the value and cost of the products and services available to us. Remember we are all addicted to the processes that produce CO2 pollution and that coming off these processes "cold turkey" could lead to political unrest and a cure worse than the disease. We need to take some of the responsibility ourselves to reduce consumption and be prepared for strong price signals that will induce different behaviour.

As people in business, we must clean up the pollution for our consumers and pass on our costs through the economy. There is only one great technological fix available at present - the capability to modify power stations to capture the CO2 they produce. Otherwise, the options are limited and unsatisfactory. We must take CO2 out of the atmosphere more quickly, using plants and trees. Sadly, the final, uncomfortable truth is that we must use the polluting processes less (which brings a concomitant risk of societal failure, but then there are no guarantees that we will survive this challenge.)

The effect on the economy will be significant, but will be less if the rate at which we need to change is minimised. So we need to start as soon as possible.

Governments must create a process which measures absolute pollution levels. It must be aware that increased efficiency can often lead to the rebound effect - an increase in overall consumption. Measuring absolute levels of pollution will help avoid this trap and the problems of well-meaning but flawed "sustainable development" projects which do not even measure how much pollution they have produced or removed from circulation.

Call CO2 pollution what it is, then regulate it to cap it. Regulate it at source (and at the border of your country if it is not regulated in the country of origin.) Regulate to manage the absolute amount in the atmosphere. This means caps are more important than trades. You don't reduce the number of slaves just by creating an international slave trade. Concentrate on the cap, then the mechanism.

Tuesday, January 23, 2007

Economist podcast music

The music used by The Economist newspaper to open and close a podcast is by the Penguin Cafe Orchestra, called Perpetuum Mobile. It's on several albums, one of which is Preludes Airs and Yodels (A Penguin Cafe primer).

Why post this? Because I couldn't find this information when searching the web and never got a response from the Economist when I wrote to ask them the answer. Many thanks to David MacKay for identifying the track.

Monday, August 21, 2006

CO2 Capture and Storage doesn't always add up

BP's Frontiers magazine, April 2006, contains an interview with BP Chief Scientist Steve Koonin and a discussion on carbon capture and storage. BP are to develop a 350 MW combined cycle gas turbine to be fueled from hydrogen. A special process will convert natural gas into the clean-burning hydrogen fuel and CO2. BP announced with some environmental enthusiasm that the CO2 will be captured and pumped underneath the North Sea into the Miller field, safely separated from the atmosphere. Unfortunately, while the project is technically impressive, financially responsible and socially valuable for securing our future energy supplies, it is highly doubtful that this development is environmentally positive.

BP tells us that pumping some 1.3 million tonnes each year of CO2 into the old Miller field will have an "added bonus" of increasing the amount of crude oil produced from the reservoir. The additional production will be "up to" 40 million additional barrels of crude. These additional barrels are barrels that would otherwise have been stuck underground.

Perhaps the additional 40 million barrels from Miller will mean that 40 million barrels from elsewhere will not be produced. If so, we can relax and join in BP's environmental enthusiasm. But what if not? What if all other production will continue anyway, and instead BP just added 40 million barrels of oil to the total amount of crude that will ultimately have been produced, most of which to end up as CO2 in the atmosphere?

This second (I feel safe in saying more likely) scenario means that the CO2 cost of the "added bonus" of "up to" 40 million additional barrels must be taken away from the atmospheric benefit of capturing the CO2 in the first place. How does the overall balance look?

Roughly, one barrel of oil, after refining into components and the various parts combusted in air, equates to around 400 kg of CO2. This is a rough figure and depends on the kind of crude, refinery efficiency and fractions, but we're not an order of magnitude out. So up to 40 million additional barrels of crude gives us, roughly, up to 16 million additional tonnes of CO2 .

BP tell us that they expect to pump around 1.3 million tonnes of CO2 each year into Miller. That means for more than the first 12 years of operation, the CO2 capture operation will have put more CO2 into the atmosphere than if it had never been built. It could have vented the CO2 to the atmosphere, saved the cost of the additional equipment and the energy required to run it, and left the extra crude in the ground.

It could be that all the oil comes out after 12 years, or at some complicated rate relative to the CO2. Perhaps so, although the economics are likely to mean that one would engineer the extra oil to come out as quickly as possible to generate revenue (see below). Also, to be fair, BP did say the figure was "up to" 40 million barrels. They could get less, in which case the CO2 payback will be that bit sooner. But how soon? In fact, how long will the plant run? For longer than 12 years one would hope. Surely this depends on the economics - how do they look?

The article inevitably takes the opportunity to importune governments to step in to address the additional costs of sequestration. Somewhat odd, then, that this project is going ahead already and others are in the CO2 CCS pipeline. Perhaps BP's share of the value of 40 million additional barrels of oil, around US$3 billion at today's prices, might help to offset the sequestration costs? That might keep the plant going, at least while the additional production flows. After that, perhaps it would be financially wiser to turn off the plant.

Shame about the atmosphere.