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An independent scientist’s observations on society, technology, energy, science and the environment. “Modern science has been a voyage into the unknown, with a lesson in humility waiting at every stop. Many passengers would rather have stayed home.” – Carl Sagan

Archive for the ‘greenhouse gases’ Category

Thinking about Better Place’s EV infrastructure proposals.

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For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.
— Richard Feynman

Better Place has attracted a lot of publicity recently, including on the Today Show and in the New York Times, following their agreement with AGL Energy and Macquarie Capital Group to raise one billion Australian dollars (about USD $665 million) to build a network of electric-vehicle battery infrastructure across Australia.

Better Place’s model offers a network of battery stations, just like petrol stations, at which an attendant will swap out an electric vehicle’s discharged Li-ion battery for a newly recharged one.

Drivers belonging to a monthly subscription service gain unlimited access to Better Place stations and fully-charged batteries for their cars. While electric-car owners can still charge their cars at home, a series of stations gives them more flexibility to travel long distances despite a battery’s limited range.

These are the biggest challenges to electric vehicle adoption – even the very best electrochemical batteries give a relatively low limit to the maximum range, they take a long time to recharge, there’s no infrastructure for recharging on the go, the batteries have finite lifetimes, and they’re very expensive. There’s only so much energy you can store in a given amount of battery of any particular chemical composition, and there’s a limit to the rate at which you can pour energy back into the battery in practice – these barriers are not things you can easily get around with politics and marketing.

The Tesla Roadster, as an example of one of the few battery electric vehicles on the consumer market today for which plug-to-wheel energy consumption data is easy to find, consumes 199 Watt-hours per km. In February 2008, Tesla Motors reported that, after testing a Validation Prototype of the Tesla Roadster at an EPA-certified location, that those tests yielded a range of 220 miles (354 km) and a plug-to-wheel efficiency of 199 Wh/km. (Admittedly, the Tesla is probably sacrificing a little energy efficiency for the sake of performance, meaning that it could probably be possible to deliver better energy consumption in a vehicle designed with that consideration in mind.) I’ll use the Tesla Roadster as a specific example, mainly because such technical details of it are easy to find.

The battery in the Tesla takes 3.5 hours to charge from zero charge, and stores 53 kWh of energy. Efficiency of the charging electronics is 86%, so 62 kWh of electricity is needed for a single charge.

If you just plug in the vehicle to charge it, and it consumes 62 kWh to charge the battery, and charges in 3.5 hours, then the line power supply to the charger must supply 74 A at 240 V (AC RMS) or 144 A, on a 120 V grid. Those are very large currents, far in excess of the maximum capacity of 10 to 15 A or thereabout that we associate with standard domestic power circuits.

If you were to just plug in such a vehicle into a household electricity line socket to charge it, (at 10 A at 240 V), then a 12 hour charge would correspond to a range of 164 kilometers, or a round trip of 82 kilometers.

If you need to travel further than that in a day, then clearly “charging stations” like the Better Place model, or some kind of provision for high-current power supplies to charge the vehicles, needs to be available. In principle, at least, the Better Place business model sounds like a good idea.

The service also saves drivers time, according to the company, since Better Place attendants can swap out a battery in about three minutes, versus the few hours it takes to recharge a battery.

Keeping in mind that electricity is only as clean as its energy source, Better Place claim that their stations will purportedly recharge their stocks of batteries using electricity from renewable energy systems.

Better Place proudly proclaims that “We will build an electric vehicle network capable of supporting the switch of Australia’s 15 million gas cars to zero emission vehicles.” and that “AGL will provide all of the renewable energy—from wind and other sources—needed to power the electric vehicles and work with Better Place to optimize the network.”

The total ‘renewable’ electricity generation in Australia in 2007 was 20.964 TWh, almost all of which (14.722 TWh) is hydroelectricity.

So, if all of Australia’s current renewable energy generation, across all energy utilities – which is already used, already traded for “carbon credit”, and sold to “green power” customers – was used to power Australia’s 15 million passenger cars, assuming that they were all replaced by battery electric vehicles, then there is only enough renewable electricity generation at present for each car to travel an average of 19.2 kilometers per day, assuming that only “renewable” energy, i.e. hydroelectricity, and solar, wind, tidal or biofuel generated electricity was used to power 15 million BEVs, and that every bit of electricity generated from these systems in this country was dedicated exclusively to this use.

In 1991, cars in Australia travelled an average of 14,600 km [source], or 40 km per day. If this level of car use was maintained today (unfortunately I cannot find any newer statistics), then total renewable energy generation would have to be multiplied 2.1 times from present levels – assuming all cars were replaced with BEVs and that all the renewable electricity generation was used exclusively for charging the BEVs, and no fossil-fuel-generated electricity was used. I don’t think I really need to convince anybody that any real expansion of hydroelectricity is not something that is at all foreseeable nor really practical in Australia.

Simply muttering the magic word “renewables” three times and clicking your heels, or something, isn’t grounds for conjuring up an arbitrarily large quantity of cleanly generated electrical energy – the infrastructure has actually got to be put in place to generate that corresponding quantity of energy.

The entrepreneur wasted no time comparing the east coast of Australia, where Better Place will build “electric highways” connecting Melbourne, Sydney and Brisbane, to the West Coast of the U.S. where Agassi would like to do the same between L.A., San Francisco and Seattle. The greater Melbourne-Sydney metro area will require 200,000 to 250,000 charging stations, Agassi said. Better Place plans on deploying some 500,000 charging points for the whole of Israel.

Under the plan, the three cities will each have a network of between 200,000 and 250,000 charge stations by 2012 where drivers can plug in and power up their electric cars.

If you have 250,000 charging stations (I’m not sure if they mean 250,000 total for the east coast, or 200,000 to 250,000 each in each of those three cities.) and 21 TWh per year of renewable energy, then that’s only enough for each charging station to be able to recharge three batteries per day, which is obviously completely insufficient. (1 day * (21 TWh per year) / (250,000 * 62 kWh) = 3.7)

In practice, burning one litre of petrol in an automotive engine results in emission of 2.32 kilograms of carbon dioxide per litre. Obviously, better fuel economy means better CO2 emissions economy per kilometer.

In Australia, the average GHG emissions intensity for electricity generation is 1000 gCO2/kWh. (In Victoria, it’s obscene, about 1300-1400 gCO2/kWh.) The Tesla Roadster has a plug-to-wheel efficiency of 199 Wh/km. Therefore, the equivalent CO2 emission for the Tesla Roadster is about 20 kg CO2/100 km.

So, if you can have a petrol-burning IC engine car with a fuel economy equal to 8.62 L per 100 km or better, then in terms of CO2 emissions, it is equally as good as, or better than, such an electric vehicle. In brown-coal-powered Victoria, the point of equivalence is about 11 to 12 litres per 100 km – which basically all cars surpass, at present.

8.62 L per 100 km is 27.3 miles per gallon – so that’s approximately equal to the old CAFE standard for cars in the USA, which I’m pretty sure was 27.5 MPG, and significantly worse than the newer standard of 35 miles per gallon. It is totally practical to build cars with such a degree of fuel economy.

Whilst in principle electric vehicles are a good idea particularly in the long term, we have to realise that right now, given the current state of electricity generation in Australia, the number one priority, in terms of mitigating excessive anthropogenic emissions of greenhouse gases, has got to be the replacement of fossil fuel based electricity generation with non-polluting systems.

While we’re implementing that, I also think that improving the fuel efficiency of ICE cars and vehicles is just as easy, probably more cost effective, and capable of delivering an equal degree of improvement in the environmental intensity of the transport sector, at least in the near term, until the coal-fired electricity generators start being replaced.

Robert Merkel over at Larvatus Prodeo posted a good post on the same topic recently.

I’ll leave you with a quote from Merkel – I couldn’t agree more with this:

If I were a government minister receiving a visit from Better Place and its partners for some kind of government incentive, I’d look very long and hard at the environmental benefits we’ll get for the dough they’re asking for.

Just like solar panels, I’d expect the answer to come back – lots of money for bugger-all environmental gains. And that should be the bottom line, not slick PR campaigns that suck in a gullible mainstream media.

Written by Luke Weston

October 29, 2008 at 8:31 am

Anthropogenic GHG emissions in the developing economic powers.

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In the discussion of anthropogenic greenhouse forcing and the international political efforts to respond to it, there isn’t much of an opportunity for discussion before somebody brings up the issue of the rising economic powers like India and China. I agree that there is a very large base of emissions in China and other developing economies – they’re building the equivalent of one large power plant every 10 days or whatever it is, but they’re building all the nuclear power and hydro that they can as part of that – but if they need coal fired plants as well in this early stage of their industrialisation, then they will build those, too.

Considering that energy consumption in most developed countries has usually grown faster than GDP during the early stages of industrialization, it is to China’s credit that although its GDP has grown by 9.5% per year over the last 27 years, their carbon intensity per unit of GDP has decreased during that time, rather than increasing along with the GDP. The reduction in carbon intensity for China has meant that its CO2 increase of about 5.4% per year has amounted to a little over half of its GDP increase during the same 27 years. [1] They’re doing a far better job than was done in the industrialisation of the Western societies.

Only one seventh of the population of China has access to constant reliable electricity. Are we to stop those Chinese having that access to electricity? They want to have a prosperous, developed, first-world standard of technologically developed society for all the Chinese people – who the hell are we to say that they shouldn’t, or can’t?

They want to have the same opportunity for industrialisation that the West has had – even if that means pollution first, and clean up later, exactly like it was done in the Western societies.

If the Australian government[s] were in charge of China, you can be sure they’d be doing a far worse job in managing the rate of increase greenhouse gas emissions whilst allowing economic development.

In discussions of the politics of responding to anthropogenic greenhouse forcing in the Western world, you’ll often hear the “Blame China – it’s all their fault, not ours!” position. So, what to do?

Is the anthropogenic forcing of climate change such a pressing, important issue that suppose we’re going to tell the Chinese, no, you’re not allowed to industrialize right now – maybe in 50 years or 100 years when everyone else has slashed their CO2 emissions? You’re joking, clearly – what are you going to do, go to war to stop them from having the same standard of living that we have?

Or, perhaps, we can give them as much aid as possible to build clean alternatives to coal fired power plants while they’re industrialising?

Chinese officials claim that they are doing a great deal that is often not visible, especially for a country as large, populous, and rurally undeveloped as it is.

But working against that, and equally non-visible, is the role of multinational ventures in China in contributing to its greenhouse gas emissions. As of 2004, 23% of China’s CO2 emissions were coming from China’s manufacturing of products destined for the West, providing an interesting perspective on China’s large trade surplus. [1]

Over half of those emissions driven by demand from the West are from multinationals and foreign owned factories in China, suppling all the crap that is destined for Wal-Mart and department store shelves in Australia, the US, and other western nations. It is pointed out that China is being demonised for having become the place where the western world effectively outsources much of its pollution.

Do we have a responsibility to deal with this in China, instead of just blaming them and refusing to do anything ourselves since they’re supposedly the problem?

We could fully encourage and support the export of all nuclear power, wind turbine, solar, hydro, etc technologies from the Western nations into China – and, given the seriousness with which anthropogenic greenhouse forcing is viewed as a grave issue, give them as much direct financial aid as we can to build these technologies as an alternative to new coal fired power plants.

Instead of, say, building a nuclear power plant in Australia, Germany, Italy, the US or UK or where ever to replace a coal fired power plant, what if we could just give the money to China and they will build them instead of coal plants – talk about an emissions trading scheme! That way, we’re making the same mitigation of greenhouse gas emissions, we’ve silenced the “It’s all China’s fault, not our problem” talk, and we’ve also dealt with the political bickering in Australia (and a few other Western countries) over acceptance of nuclear power.

(Of course, this is a little hard to reconcile with the usual Western approach where power plants, nuclear, fossil or otherwise, are built and operated by corporations who can sell their electricity for profit – it really only makes sense in the context of nations operating under state ownership of power plants, like, say France.)


Written by Luke Weston

July 10, 2008 at 11:30 am

Switching off Victoria?

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I was quite impressed with myself to discover, the other day, that everybody’s favourite opinionated newspaper columnist, Andrew Bolt, had linked to and cited one of my recent posts.

That’s probably responsible, at least in part, for the significant increase in traffic I’ve seen on this blog over the last week or so – and I’m grateful for that.

Sometimes Bolt is absolutely on the money – but not always.

Here’s a recent blog post of Bolt’s which is somewhat agreeable, but still gets on my nerves a little bit. It’s worth reading, anyhow.

It’s utterly unbelievable that the Rudd Government should be contemplating making bankrupt the stations that provide more than 90 per cent of Victoria’s power:

Yes – it is extremely worthwhile and important to close down the extremely polluting and greenhouse gas emissions intensive brown coal fired power stations that provide more than 90 percent of Victoria’s electrical energy. That does not mean making the energy companies bankrupt – we still need that energy, it just has to come from a different source.

However, I too would have a hard time believing that Rudd would or could actually make it happen.

Although careful to respect the Federal Government’s process, Victorian Energy Minister Peter Batchelor appears increasingly nervous in his public comments. Asked if one of the state’s brown coal generators will be forced to close prematurely, he said: “It depends on the nature of the emissions trading scheme (introduced).”

The purpose of a GHG emissions trading scheme is to mitigate anthropogenic greenhouse gas emissions from our industries. Its purpose is not to raise more government revenues or to create more paperwork – its purpose, its reason for existing, is to reduce industrial, anthropogenic emissions of carbon dioxide.

Therefore, if the “mud-burning” Latrobe Valley stations are not the very first things to close down under an emissions trading scheme, then clearly the scheme is not working.

If it’s one like Garnaut actually recommends – with no compensation to power stations for wiping billions off their value – the generators are cactus. And here is Kevin Rudd’s modus operandi writ large and destructive: process over purpose. What possible good could there be to cause such an economic catastrophe in this state?

But Rudd’s guru has a solution of the kind the Soviet Union would have suggested:

In his report, Professor Garnaut said $1 billion to $2 billion of the emissions trading scheme proceeds should be invested in clean coal technologies, matched dollar for dollar by the companies. If clean coal worked, he said, the Latrobe Valley would heave a “prosperous and expansive future”. If it didn’t, money from the scheme should be used to help retrain workers and to help the valley community survive the brave new world of zero emissions.

Hey, let the Government spend a couple of billion of taxpayers’ money, and another couple of billion of the bosses’, on a yet-to-be proved “solution” many experts say is pie in the sky. And then, $4 billion later, let’s give the unemployed some handouts.

Warning: These people now have their hands all over your jobs and paypackets.

Whilst I’m interested – and many others are interested – in seeing the coal fired plants closed down, that doesn’t mean that the electricity utilities are out of business – we still need the electricity, and we will continue to need the electricity.

Ideally, what we would see happening is the construction of new lower-emissions or zero-emissions electricity generators of an energy output comparable to the coal power plants, followed by the decommissioning of the coal-fired plants. [Of course, we don’t decommission the coal plants until after the new ones are online.]

The electricity utilities are still operating lower-emissions or zero-emissions generators, there are still people employed, and we’re still getting the energy needed to support developed civilisation. This is where we need to transition to, and where an emissions trading scheme – if it’s done right – might help us transition to.

I agree that investing many billions of dollars in CCS research and development, which is considered by many to be pie in the sky, is a grave mistake. Instead, we need to consider the energy generation technologies that are mature technologies that are available and proven right now, that can replace coal-fired power plants, generating energy at a comparable scale, for less GHG emissions.

Those options are large hydroelectricity, natural gas fired turbines, and nuclear fission.

In Australia, expanding the use of large hydroelectric installations above and beyond what we’ve already got is really not a practical proposition, so we’re left with two options that really could replace coal-fired generators in the Latrobe valley, under an emissions trading scheme – natural gas and nuclear energy. Certainly, what is absolutely not sensible at all is arbitrary, unfair and exceptional, scientifically unfounded legal prohibitions on the development of nuclear power plants by the energy companies who are willing to invest in zero-emissions replacement for coal, especially when their investments may be kick started by billions of dollars in the government’s ETS revenue, which clearly needs to be put back into these zero emissions or lower-emissions technologies.

If power plant operators wish to pursue either of these options, which will finally actually put a stop to the ever-expanding use of coal-fired generators, and finally put a real dent in GHG emissions, then they are to be wholeheartedly encouraged in doing so.

Obviously the nuclear energy option is completely superior to natural gas in terms of greenhouse gas emissions – however, in practical terms, one must grant that gas turbines are already in widespread use in Australia today, and they are more politically acceptable in some political circles than nuclear power – however that may change as concern over greenhouse gases, even at the somewhat reduced levels from natural gas generators, grows.

However, that said, given the importance of making real cuts in GHG emissions within the next 3-10 years, if the generators want to build combined-cycle natural gas turbines, technologies with which they’re more familiar, straight away, then they shouldn’t be discouraged. Natural gas could offer some benefit as a stopgap measure for last-ditch replacement for coal fired plants in the absence of nuclear power.

More on the Garnaut report.

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The next thing that gets on my nerves about the Garnaut report is its repeated emphasis – and optimism – on what are described as “near-zero emissions coal technologies”.

The success of near-zero emissions coal technologies will mean that new fossil fuel plant will continue to be coal, while Australia continues to gain as an exporter from the ongoing high global gas prices.”

“For Australia, the importance of reducing emissions from coal combustion is of large national importance.”

If this industry is to have a long-term future in a low-emissions economy, then it will have to be transformed to near-zero emissions, from source to end use, by the middle of this century. A range of technical, environmental and economic challenges must be addressed effectively to achieve this objective, in a time frame consistent with a global agreement on climate change and Australia’s own domestic commitment.

There is seemingly precious little discussion about the maturity of such technologies, how scalable they are, how far they are away from practical widespread use, the extent to which they actually mitigate carbon dioxide emissions, and how much these technologies will cost, and their economic competitveness, even under a GHG emissions trading scheme.

At its simplest, the challenge is to develop technologies that allow coal combustion with zero, or near-zero, carbon dioxide emissions while maintaining its relative competitive position as a fuel.

Those same forces of high capital costs, high world gas prices and relatively strong export coal prices will strongly favour retrofitted (post-combustion capture) coal plants with captive coal supplies and low-emissions profiles and ultimately, near zero emissions plants involving integrated coal drying and gasification technology.

This notion of “zero-emissions” or “near-zero-emissions” from coal is simply ridiculous and unfounded.

The IPCC Special Report on Carbon Capture and Storage reports that:

“Available technology captures about 85–95% of the CO2 processed in a capture plant. A power plant equipped with a CCS system (with access to geological or ocean storage) would need roughly 10–40% more energy than a plant of equivalent output without CCS, of which most is for capture and compression. For secure storage, the net result is that a power plant with CCS could reduce CO2 emissions to the atmosphere by approximately 80–90% compared to a plant without CCS.”

There’s an interesting paper here which provides a realistic analysis of the implementation of retrofitted CO2 capture for an existing pulverised coal power station.

This paper examines the retrofit of a 400 MWe pulverized-coal fired plant emitting 368 t/h of CO2 to enable CO2 capture while maintaining 400 MWe output, where 90% of the CO2 emitted from the coal plant is captured. To do so, the extra energy required for capturing CO2 was supplied by natural gas-fired gas turbines.

I’ve quoted the key points from the paper below. I’ve applied some minor editing and collation, but most of the material is straight from the paper cited.

Even when CO2 emitted from the gas turbines is not captured, the overall process still have some impact in reducing CO2 emissions, corresponding to an overall reduction in carbon dioxide output to the atmosphere of between 60-70%, with atmospheric CO2 emissions of between 110 and 138 t/h, compared to 368 t/h for the original coal combustion plant, at the cost of a natural gas requirement of about 1350 GJ/h.

When CO2 from the gas turbines is captured, the reduction in CO2 emission is between 68 and 77%, or CO2 emission to the atmosphere of 86-113 t/h. However, a considerably large amount of natural gas is required (around 3140 GJ/h), which is certainly not reasonable.

The total amount of natural gas required is between 3100 and 3300 GJ/h. To put this number into perspective, this amount of natural gas would generate about 460 MWe when used in a combined-cycle gas turbine plant without CO2 capture. The relative emissions are between 23% and 32% of the original coal power plant, which has a significant impact on the reduction of CO2 emissions.

In addition to the cost analysis, the future work will investigate other possibilities of integrating gas turbines into the coal power plant. The configuration presented in this paper represents one extreme, where all the electricity is generated from coal and the auxiliary power is generated from the gas turbine and natural gas boilers. Another extreme is to consider the classical view of producing all the auxiliary power from the coal plant, at the expense of decreasing the net electrical output. To compensate for the lost electrical output, a combined-cycle gas turbine with CO2 capture will be added. Combinations between these two extremes will also be investigated.

For a nameplate capacity of 400 MW, and a capacity factor which we may assume to be, say, 85%, carbon dioxide emissions of between 86 and 138 t/h correspond to emissions of between 253 to 406 grams of carbon dioxide per kWh generated.

The results from this study certainly paint a less optimistic assessment of the carbon dioxide emissions intensity of “clean coal” than the 80-90% reductions estimated by the IPCC.

That’s not clean coal. Much like the use of fossil fuel methane, it’s a bit cleaner, but it certainly isn’t clean.

Indeed, such levels of carbon dioxide emissions intensity are not much better than existing high efficiency combined-cycle natural gas fired gas turbine power plants. Given that the carbon dioxide emissions aren’t grossly worse, and given that gas turbine plants are already established, mature technology which is likely to remain far more economically competitive with this expensive, immature, unproven future technology, it is easy to envision that natural gas will be the main focus of the fossil fuel combustion energy industry over coming years, as opposed to the development of CCS technology, even where emissions trading is introduced.

The exception to this, of course, is where there is a vested interest in keeping the existing coal-fired power plants, and enormous coal-mining infrastructure, even if it is a less than sensible choice on many different levels. Natural gas turbines are of course, along with nuclear power, by far one of the biggest “threats” to the coal mining and coal-combustion electricity generation industry.

Additionally, that’s only considering greenhouse gas emissions from combustion at the power plant – without any consideration of whole-of-life-cycle analysis of coal mining and natural gas production – the enormous scale on which coal is mined, along with the fugitive emissions associated with the production and handling of natural gas, and so forth.

There is a large body of literature and knowledge of the whole-of-life-cycle analysis of energy intensity, environmental impact and greenhouse gas emissions associated with, for example, nuclear power, solar photovoltaics or wind power.

However, since fossil fuel combustion energy generation has such a comparatively fantastically high level of carbon dioxide emissions in the combustion process itself, I feel that sometimes it’s easy for some of us to forget that it’s only sensible to apply the same metrics across the life cycle for fossil fuels, just as people insist on analysis the impact of the entire life cycles for nuclear energy or solar energy, for example.

What is desperately needed is further research into the life cycle analysis of coal or other fossil-fuel combustion based energy generation systems when they are combined with proposed carbon capture and storage technologies. This is clearly important if a fair comparison is to be made between the economic and environmental feasibility of fossil-combustion CCS and alternatives such as nuclear power, wind, hydro or so forth.

Personally, I believe that as such analyses are performed, the extreme skepticism with which many of us view the comparative practicality of these “low-emissions” fossil fuel combustion technologies will begin to be vindicated.

The Garnaut climate change review draft report.

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As many of you will know, Professor Garnaut’s much-awaited Draft Report on the implications of anthropogenic climate change in Australia was recently released. Let’s take a look at it.

[There’s a mirrored host here, courtesy of the GreensBlog. Please be aware that that’s a direct link to a very large PDF file.]

I haven’t read the entire thing yet, and I don’t expect that many of you have, either.

In some industries, notably aluminium smelting and some steel production, indirect emissions in generating electricity would need to be taken into account. These emissions could be assessed according to a simple and robust approximation, based on the emissions intensity of the systems from which they draw their power, and made subject to the sectoral emissions tax. Indirect or embodied emissions that fell below a threshold would not be considered, in the interest of simplicity.”

“Chapter 9 suggested that under a reasonable set of assumptions about the threshold ratio and the permit price, only a limited number of industries might clearly satisfy the emissions intensity eligibility criteria. As the permit price rises, they may include — assuming an economy-wide emissions trading scheme — aluminium smelting, cattle and sheep products, cement production, and iron and early stage steel manufacturing.”

It all sounds terribly complicated, doesn’t it? I’ll be the first to profess that I’m not an economist, however.

The example of the aluminium production industry is one that gets bought up again and again in the context of high-GHG-emissions industries, and it raises an interesting question.

An aluminium smelter itself does emit a little bit of carbon dioxide and other GHGs, but not all that much by comparison to most other large industrial chemical and metallurgical engineering.

What an aluminium smelter does do, however, is consume large amounts of electrical energy, and this is where this notion about the aluminium industry being responsible for vast amounts of GHG emissions comes from.

The aluminium producer buys their electricity from the grid from the electricity generating utility. If we assume that this utility is predominantly operating coal-fired plants, then the utility is paying a high price for its large carbon dioxide emissions, under an emissions trading scheme.

The utility will inevitably pass this cost onto electricity consumers – so, is an industry such as the aluminium industry or steel industry being expected to pay for the carbon dioxide intensity of their energy use twice – once in the price of their electricity, and again simply because they’re using that electricity? That’s what the above passage seems to imply, doesn’t it?

The same scenario applies to every one of us, with regards to household electricity consumption. Could you reasonably be expected to pay for “your” carbon dioxide emissions corresponding, even after you’ve already paid them in the form of the bill from your electric utility?

Just like aluminium smelters or electric arc furnaces in industry, light bulbs or plasma TV’s aren’t responsible for significant direct greenhouse gas emissions – it’s fossil fuel combustion power stations that are.

Now, I’m pleased to note that there’s at least some mention of nuclear energy in the report, and it’s interesting to take a look at that, too.

This renewed demand arises from a combination of influences from climate change, energy security and relative costs. With more than one-third of currently estimated global uranium resources, Australia is well placed to benefit from this growth.

Doesn’t this sound – coincidentally – very much like the “Nuclear energy is fantastic for Australia – just as long as it isn’t actually in Australia” policy of the federal government?

The 2006 Uranium Mining, Processing and Nuclear Energy Review for the Commonwealth Government concluded: ‘Although the priority for Australia will continue to be to reduce carbon dioxide emissions from coal and gas, the Review sees nuclear power as a practical option for part of Australia’s electricity production. This conclusion was based on a cost of nuclear power of $40–65/MWh, which is within the range of the $35–80/MWh estimate of the Nuclear Energy Agency and the International Energy Agency from 2005, but below ranges specified in the more recent official UK publications of $60–80 MWh. Nuclear power stations will have been disproportionately affected by the recent increases in capital costs on account of their exceptional capital intensity, and will have been rendered less competitive by this development. Newer-generation nuclear technologies indicate potentially lower costs.

Less competitive with what? Less competitive in the presence or in the absence of an emissions trading scheme? How less competitive?

Increases in capital costs affect all energy systems – nuclear energy, fossil fuel combustion, solar, wind… you name it. In terms of the relative sensitivity to capital costs of nuclear power plant construction for a given amount of energy generated, nuclear energy is indeed quite competitive.

“Australia has better non-nuclear low-emissions options than other developed countries, especially (but not only) if carbon capture and storage is commercialised within the range of current cost expectations. Australia is a major net exporter of a wide range of energy sources, notably coal, liquefied natural gas and uranium. Transport economics should favour local use of those fuels in which the gap between export parity and import parity price is greatest (first liquefied natural gas, then coal). As a consequence, Australia is not the logical first home of new nuclear capacity on economic grounds.”

This sounds like the oft-encountered yet worrisome “fossil fuel combustion is the cheapest source of energy – so just use that instead, without bothering with those more expensive sustainable low or no emissions alternatives” reasoning.

Is that perhaps what we have to expect when we put economists in charge of preparing a review for the government of the impacts of anthropogenic greenhouse effect forcing in Australia?

Without real attention paid to the environmental impacts of fossil fuel combustion, the health impacts, and the energy security impacts, no energy system is competitive with cheap, abundant coal and petroleum on economic grounds.

“In Australia, as well as in most other developed and developing countries, public acceptability is an important barrier, that would need to be recognised as a constraint and a source of delays and increased costs by any government committed to implementation of a nuclear power program.”

“Given the economic issues and community disquiet about establishing a domestic nuclear power capacity, Australia would be best served by continuing to export its uranium and focusing on low-emissions coal, gas and renewable options for domestic energy supply. However, it would be wise to reconsider the constraints if:

• future nuclear costs come in at the low end of the estimates provided above
• developments in technologies reduce the need for long-term storage of high level radioactive waste
• there is disappointment with technical and commercial progress with low emissions fossil fuel technologies, and
• community disquiet eases.”

Many who support nuclear power already believe that the failure of fossil fuel combustion with CCS technology to deliver truly competitive and truly low-emissions energy is a foregone conclusion for the next several decades at least.

As for dealing with used nuclear fuel and high level radioactive waste efficiently, sensibly and safely, the efficient recycling of nuclear fuels and the deep geological permanent disposal of unusable long-lived radioactive wastes are already scientifically and technologically solved problems – only political debate remains as the “unsolved problem”

Ongoing developments in the design and construction of Generation III, III+ and IV are working to address concerns over the economics of nuclear power, as do rising natural gas and fossil fuel prices. The introduction of GHG emissions trading schemes increases the economic acceptability of nuclear energy still further, relative to other energy systems. It is always essential to approach these issues in the context of meaningful comparisons to other forms of energy generation – or realistic degrees of reduction in demand, or the slowing of demand growth. The energy, ultimately, has to come from somewhere.

This leaves public acceptance of nuclear power – supposedly – as the overwhelming issue preventing nuclear energy use within Australia.

Does this supposed community disquiet truly exist to a significant degree, or is it merely the meaningless noise of a vocal, fervent and dogmatic minority?

Acceptance of nuclear energy amongst the public may be swayed by dramatically increased energy costs, and failures to achieve desired reductions in GHG emissions, if real alternatives to coal and fossil fuels are not deployed in a meaningful way.

The 2007 McNair Gallup poll found 53% of Australians were opposed, 41% were in favour of the construction of Nuclear power plants and 6% were uncommitted.

It seems from the 2007 McNair Gallup poll that the need to consider nuclear power as an alternative energy source is considered increasingly popular amongst Australians, with more Australians conceding the need for nuclear power plants to be built in Australia.

The 2007 results contradict Peter Garrett’s claim that “Australians are very clear that they don’t want nuclear energy and nuclear power in this country.”, with 41% of Australians in favour for the construction of nuclear power plants.

Other informal polls, such as those run on the websites of Australia’s major newspapers every once in a while, continually return strong majority support for nuclear power. Some may question the reliability and coverage of such polls – but it is clear that as concern over anthropogenic greenhouse forcing and the use of coal grows, along with concerns of the economic impacts of GHG emissions trading and the need for large scale energy generation also grows, more effort needs to be made to gauge the true degree of community support for a rational, informed and sensible consideration of nuclear energy – along with greater education of the public, which is increasingly desired by the community.

In fact, I am not unconvinced that there is not already majority support for a rational, informed, dogma-free and sensible consideration of nuclear energy amongst the Australian public today.

Nitrogen trifluoride as an anthropogenic-greenhouse-forcing gas.

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A couple of articles in the media captured my interest this evening:

TV boom may boost greenhouse effect
Plasma, LCDs blamed for accelerating global warming

I must say, this looks like more biased “You’ve got a TV? You’re guilty of climate change!” baloney from the “green” fanatics in the press who like spinning scientific papers out of context.

Nitrogen trifluoride is used in the plasma and thermal cleaning of chemical vapor deposition (CVD) reactors in the semiconductor industry. It is also used as a source of fluorine radicals for plasma etching of polysilicon, silicon nitride, tungsten silicide, and tungsten, in which application it can replace perfluorocarbons such as hexafluoroethane and sulfur hexafluoride, resulting in both ecological advantage and improved process efficiency. NF3 is an alternative to these other potent greenhouse gases and its usage has increased markedly over the last decade.

This has got nothing to do specifically with manufacturing plasma TVs, and everything to do with manufacturing semiconductor devices and materials such as polycrystalline silicon.

One has to wonder what the emissions of sulfur hexafluoride, perfluorocarbons and/or nitrogen trifluoride are for the manufacturing of a typical plasma TV, and how it compares to the emissions of sulfur hexafluoride, perfluorocarbons and/or nitrogen trifluoride over the manufacturing of, say, one typical solar photovoltaic panel. Obviously a photovoltaic panel has got much more polycrystalline silicon in it than your TV – yet, do we hear anything about manufacturing of solar photovoltaic cells in this regard?

In fact, worldwide interest in sustainable energy systems and the ensuing growth of the solar photovoltaics industry is one of the main forces driving increased industrial demand for nitrogen trifluoride and other gases employed in the processing of semiconductor materials:

Emerging thin-film solar cells will be based on thin-film deposition technologies including CVD processing, says industry analyst Mike Corbett, managing partner of Linx Consulting, based in Boston, Massachusetts, US.

“Basically, tandem-cell thin-film solar cell production uses similar CVD tool sets as those used in the LCD industry. So as thin-film solar cells become more popular, there will be a high volume-growth potential for these gases,” says Corbett.

According to US-based industrial gas supplier Air Products, solar capacity is growing at more than 30%/year.

“With photovoltaics using many of the same raw materials as semiconductor manufacturers, we would expect to see strong growth in the products Air Products supplies to the photovoltaics industry,” says Dave Tavianini, photovoltaics business development manager for the company.

Looking ahead, Tavianini adds, demand for specialty gases will continue to accelerate as second-generation thin-film siliconphotovoltaics proliferate.

[From here]

The use of such materials applies to basically everything containing semiconductors – essentially all modern electronic technologies are equally relevant, from your PC to your TV to your solar panels to your PC to your cellphone. Semiconductor technology is a fundamentally important cornerstone of our modern civilisation.

Nitrogen trifluoride is a potent greenhouse gas, with a global warming potential (GWP) of 17,200 over a 100 year timescale. This places it second only to sulfur hexafluoride in the group of Kyoto-recognised greenhouse gases. It has an estimated atmospheric lifetime of 740 years, though newer research suggests a slightly shorter lifetime of 550 years and a GWP of 16,800.

With 2008 production equivalent to 67 million metric tons of CO2, based on estimated emissions for 2008, it has been calculated that NF3 may play a more significant role than emissions of the industrialized nations of perfluorocarbons or sulfur hexafluoride, which are included in the Kyoto protocol.

Increased wafer size and reduced critical dimensions demand higher process stability and often new processes. With new production lines being built newer and generally more severe environmental statutes apply. On top of that, there is the worldwide goal of perfluorocarbon emissions reductions.

Regarding the consumption of perfluorocarbon etch gases, chamber cleaning processes are the major contributor. Since the utilisation of etch gas in these processes is usually less than 50%, the remaining gas has to be destroyed and removed by a waste gas abatement system. Generally, for CVD and etch processes, waste gas abatement is necessary for several reasons, certainly including but not limited to environmental concern and legal restrictions on emissions of greenhouse-forcing fluorinated gases.

Tetrafluoromethane is used in the microelectronics industry alone or in combination with oxygen as a plasma etchant for silicon, silicon dioxide, and silicon nitride. Tetrafluoromethane is a gas that contributes to the greenhouse effect. It is very stable, lasts a long time in the atmosphere, and is a powerful greenhouse gas. Its atmospheric lifetime is 50,000 years and it has a global warming potential of 6500.

Hexafluoroethane is also used as a versatile etchant in semiconductor manufacturing. It can be used for selective etching of metal silicides and oxides versus their metal substrates and also for etching of silicon dioxide over silicon. Hexafluoroethane is very stable in the atmosphere and thus acts as an extremely potent greenhouse gas, with an atmospheric lifetime of 10,000 years and a global warming potential (GWP) of 9200.

Sulfur hexafluoride is also used as a plasma etchant in the semiconductor industry, along with other technological applications. It is the most potent greenhouse gas known, with a global warming potential of 22,800 over a 100 year time horizon – SF6 is very stable. Its mixing ratio in the atmosphere is lower than that of CO2; about 6.5 parts per trillion in 2008, compared to 380 ppm of carbon dioxide.

Recently, the use of NF3 as an etch gas for chamber cleaning processed has been reported to give promising results, and use of this gas has been increasing. Aside from the advantage of less wear on the chamber, gas consumption is lower, since the utilisation of NF3 is very high, at 85 to 99\%. At the same time NF3 has a far smaller atmospheric lifetime of 550 years than standard etch gases like tetrafluoromethane and hexafluorethane, with estimated atmospheric lifetimes of 50,000 and 10,000 years, respectively.

When comparing the global warming potentials of these gases, a 100-year integrated time horizon is used, and the benefit of using nitrogen trifluoride to replace the alternative reagents with regards to anthropogenic greenhouse effect forcing is obfuscated for that reason.

Global Warming Potentials over an 100-year integrated time horizon:

Tetrafluoromethane: 6500
Hexafluoroethane: 9200
Nitrogen trifluoride: 16,800
Sulfur hexafluoride: 22,800

Atmospheric lifetimes:

Nitrogen trifluoride: 550 years
Sulfur hexafluoride: 3200 years
Hexafluoroethane: 10,000 years
Tetrafluoromethane: 50,000 years

The fact is, nitrogen trifluoride presents an environmentally friendlier alternative to sulfur hexafluoride, and arguably an environmentally friendlier alternative to perfluorocarbon gases.

Whilst these inorganic fluorine compounds and perfluorocarbons have large global warming potentials, which make for dramatic media headlines, their atmospheric abundances and mixing ratios are very small, and hence their contributions to radiative forcing in the atmosphere and hence to anthropogenic forcing of climate processes are very small by comparison to carbon dioxide, methane and water vapor.

Carbon dioxide is responsible for an increased radiative forcing term of 1.66 W/m2, according to up-to-date IPCC data, along with 0.5 W/m2 for methane and 0.16 W/m2 for nitrous oxide. For comparison, sulfur hexafluoride is associated with a far smaller increased radiative forcing term of 0.002 W/m2, along with 0.001 W/m2 for perfluoroethane. We can reasonably expect that the contribution from nitrogen trifluoride is similar, at around 0.001 to 0.002 W/m2. Whilst nitrogen trifluoride is certainly worthy of inclusion under the Kyoto protocol, along with perfluorocarbons and the like, especially as worldwide consumption of the gas grows, it is however nothing worth making a huge irrational fuss in the media about.


Robson, J. I., L. K. Gohar, M. D. Hurley, K. P. Shine, and T. J. Wallington (2006), Revised IR spectrum, radiative efficiency and global warming potential of nitrogen trifluoride, Geophys. Res. Lett., 33, L10817, doi:10.1029/2006GL026210.

Prather, M. J., and J. Hsu (2008), NF3, the greenhouse gas missing from Kyoto, Geophys. Res. Lett., 35, L12810, doi:10.1029/2008GL034542.

Reichardt, H., Frenzel, A. and Schober, K., Environmentally friendly wafer production: NF3 remote microwave plasma for chamber cleaning. doi:10.1016/S0167-9317(00)00505-0

Australia 2020 Summit – Initial Report

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The (initial) report from the Australia 2020 summit has been released.

It says this:

“By 2020 Australia will be making a major contribution to a comprehensive global response to climate change, including working with our partners on clean energy. Australia will have dramatically reduced our emissions, and communities, regions and business will be actively assisted to adopt the unavoidable consequences of climate change.”

But how will those emissions of greenhouse gases be “dramatically reduced”? There is essentially nothing in the report indicating that much thought has been given at all to how those emissions will be reduced on an appropriate chronological scale.

What’s more, astonishingly, there is no mention – no mention at all – of nuclear energy in the report. There is no “nuclear energy is good”, no “nuclear energy is bad”, no “no, we must not waste our resources with nuclear energy”, no “we should look into the nuclear energy option” – absolutely nothing!

What exactly have these delegates been doing, for goodness sake?

Those anthropogenic greenhouse gas emissions aren’t going to mitigate themselves.

Written by Luke Weston

April 20, 2008 at 9:00 am

Earth Hour, candles and carbon

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There’s one thing in particular that bothers me about Earth Hour – these people who electric lights and then go and light up candles, and think that they’re helping do something about anthropogenic forcing of climate change.

The widespread practice of misguided eco-Luddites turning off their lights for Earth Hour and burning candles as a source of light is grossly misguided and actually contributes to increased carbon dioxide emissions.

Yes, I know candles are nice and romantic – but you’re taking paraffin wax, in the form of a candle, and burning it, very inefficiently, at a low temperature. This stuff is pure hydrocarbon – it’s a heavy alkane fraction distilled straight off crude oil. This stuff is getting so scarce that nations are prepared to go to war just to secure it, remember?

A candle flame burns at a low temperature – so it’s a thermodynamically very inefficient source of energy – and most of the energy released in a candle is wasted as heat, anyway.

Even if 80% of your electricity comes from coal and fossil fuel fired power stations, as it does in Australia, burning candles is very polluting and certainly very greenhouse gas and carbon dioxide emissions intensive, even more so than electric lighting.

If you need to do something that requires light – then leave an electric light on – just one. It’s far more efficient, less carbon dioxide emissions intensive and better for the environment – not to mention much safer than using hazardous candles.

If you want the romance of a candle, try looking for candles that you are certain are made from pure “carbon neutral” beeswax or tallow – not from crude oil in the form of paraffin wax.

Can’t we just put science, reason, rationality, education and reason ahead of trendy politics and trendy dogmas – before it’s too late?

What Earth Hour should not be about is the notion that we want to have a civilisation without artificial lighting – this is absolutely ridiculous. Lighting up the darkness was one of the most useful technological achievements in human history – why would we give that up?

Using electricity for lighting is far more efficient and environmentally sound than the primitive technologies, burning fossil fuels dirtily, at ambient pressure and relatively low temperatures, that came before electrification.

The use of electricity, and the use of electric lighting, is part of our way of life, in a developed, technological first-world society – I, for one, am not prepared to give that up, not the least because we don’t have to.

Light bulbs don’t produce greenhouse gases – burning fossil fuels to generate electricity does.

Let’s focus our efforts on moving away from fossil fuel based electricity generation, and expanding the use of non-greenhouse gas intensive hydroelectricity, nuclear energy, and wind energy, to solve our problems with anthropogenic greenhouse gas emissions.

Earth Hour should be about doing everything that you can to reasonably, sensibly limit your demand for electricity – and we can do this every hour of every day, of course. It makes sense for everyone – after all, you pay for the electricity.

I guess I have a problem with the idea that Earth Hour symbolises something.

It might symbolise something, but it doesn’t actuallydo anything.

The only thing it symbolises is primitive society.

I’d much rather see people spend their Earth Hour doing something that really does count for something.

Instead of spending your Earth Hour bearing with an uncomfortable, dark lifestyle, use that hour to think about the things that we can all do every day to limit electricity consumption, that we will actually bother to do every day, that are compatible with the fact that, yes, in our developed first-world society, we actually use electricity, and we work after the sun goes down. Think about the things that are compatible with our sensible lifestyles in the developed world, and do them, and it works out better for everybody!

Now, let’s consider just how much, quantitatively, this use of candles during Earth Hour is responsible for increased emissions of greenhouse gases.

Postulate I: A typical candle produces about 13 lumens of visible light, from a total power output of about 40 W, most of which is heat.
Postulate II: A 40 W electric incandescent light bulb consumes 40 W of electric power, and produces approximately 500 lumens of visible light output.
Postulate III: The overwhelming majority of candles are made from petroleum, in the form of paraffin wax. Paraffin wax has a heat of combustion of approximately 42 kJ/g, and can be assumed to consist, chemically, entirely of pentacosane – \mathrm{C_{25}H_{52}}.
Postulate IV: The average greenhouse gas emissions intensity for electric power generation in Australia is about 1000 g \mathrm{CO_{2e}}/kWh, and electricity is transmitted with transmission losses of about 7%.

\mathrm{C_{25}H_{52}(g)\ +\ 38\ O_{2}(g)\ \to 26\ H_{2}O(g)\ +\ 25\ CO_{2}(g)}

\mathrm{M(C_{25}H_{52})} = 352.68 g/mol;

\mathrm{M(CO_{2})} = 44.0 g/mol.

Thus, we know the emission of carbon dioxide from burning candles:

\mathrm{\frac{40\ W/candle\ \cdot\ 25\ mol/mol\ \cdot\ 44\ g/mol\ \cdot\ 3600\ s/h}{4.2\ \times\ 10^{4}\ J/g\ \cdot\ 352.68\ g/mol}\ =\ 10.69\ gCO_{2e}} – per candle per hour.

And the rate of carbon dioxide emissions from the electricity generation corresponding to the use of 13 lumens worth of lighting – the equivalent of one candle – for one hour:

\mathrm{\frac{13\ lumens/candle\ \times\ 1000 g/kWh\ \times\ 107\%\ \times\ 40\ W\ \times\ 10^{-3}\ kW/W}{500\ lumens}\ =\ 1.11\ gCO_{2e}} – per candle-equivalent of electric light per hour.

Therefore, for every candle that is burned to replace electric lighting during Earth Hour, greenhouse gas emissions over the course of the one hour are increased by 9.6 g of carbon dioxide.
If the light output from a 40 W light bulb was to be completely replaced by candles, this will lead to the emission of an extra 295 grams of carbon dioxide per over simply using the electric lights – if the equivalent of one thousand 40 W bulbs are replaced by candles, that’s an extra 295 kilograms of \mathrm{CO_{2}} emitted.

In places where a greater proportion of the electricity supply is generated by nuclear energy or hydroelectricity, this increase in greenhouse gas emissions is even larger.

Written by Luke Weston

March 31, 2008 at 5:13 pm

Life-cycle analysis of energy intensity and greenhouse gas intensty of nuclear energy.

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This is a very, very comprehensive and useful work – and especially good literature review – of Whole-of-Life-Cycle analysis of the energy intensity and greenhouse gas intensity of nuclear energy.

There’s one key point that stands out specifically, again and again when reading it.

We’ve come to the same conclusion before, and most of you reading this blog probably know exactly what I’m talking about, but let’s just spell it out:

Jan Willem Storm van Leeuwen and Philip Smith are WRONG.

Written by Luke Weston

July 29, 2007 at 3:17 pm