Physical Insights

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

Burning money with solar power in Victoria. Again.

It has been announced this week that the Victorian Government will promote renewable energy by spending $100 million to establish a new regional solar power station, subject to the Federal Government matching its commitment. Premier John Brumby will announce both initiatives today, focusing on the plan for a 330-gigawatt hours per year solar plant with the capacity to power the equivalent of 50,000 homes. All right. More kumbaya and rainbows and sunshine courtesy of Brumby. This proposed new solar power station will supposedly generate 330 gigawatt-hours of electrical energy per year. (The Age article originally mentioned a “330 gigawatt” plant, but they later caught the egregious mistake and edited it.) How much energy is that? In 2006, Loy Yang unit A in Victoria generated 15,995 GWh of electrical energy, sent to the grid. (In doing so, it emitted 19,314,994 tonnes of CO2 equivalent, and a whole lot of other environmentally and aetiologically nasty, dangerous, toxic waste, such as fly ash, SO2 and NO2, as well.) That’s just one example of one of the coal-fired generators, of course. Therefore, this proposed solar power station is generating about 1.88 percent of that one single coal-fired generating station. How much will this plant cost? We don’t know. The article doesn’t say, nor does Brumby’s original press release. We don’t know how much it costs, and I doubt Brumby knows, either. …promote renewable energy by spending$100 million to establish a new regional solar power station, subject to the Federal Government matching its commitment.

OK… we know that it costs at least $200 million. There is actually a convenient benchmark which we can use to make an estimate of how much the whole project will actually cost, and that is the$420 million solar energy installation planned by Solar Systems for northwestern Victoria. This is another expensive solar energy project that the Victorian government just loves to talk about as a poster child for their clean, green ways.

The Solar Systems project, with 154 MW of nameplate capacity, will generate 270 GWh per annum, and will cost 420 million dollars. If we assume that the newly proposed 330 GWh/annum installation might cost about the same, for a given amount of capacity, then we can expect that it will cost 513 million dollars.

To replace Loy Yang A, to have the equivalent amount of energy generation, you’d need 49 such installations of this size, at a cost of approximately 25 billion dollars to construct.

If you build a modern* nuclear power plant, with two 1100 MWe reactors operating with a 90% capacity factor, the plant will generate about 17,356 GWh per annum. That is, such a plant will replace Loy Yang A’s output about 1.09 times over; it’s more than sufficient.

How much does it cost, to build such a nuclear power plant?
Go on, consider an exaggerated, extra-conservative cost estimate from your local greenies. 9 billion dollars? 12 billion? 14 billion? 15 billion?

In every case, even with the most pessimistic cost estimates for nuclear power, it’s far, far cheaper than solar, assuming that you’re actually capable of counting kilowatt-hours.

(* Modern, but not bleeding edge. We’ll consider the presently available modern Generation III LWRs such as Westinghouse AP1000 that are available immediately, not Generation IV fast spectrum reactors, liquid fluoride reactors, or things like that, just to be a little conservative about it.)

Brumby’s press release says that they aim to have the plant operating by 2015. So, they aim to have the plant operating within six years.

Six years? To think that opponents of nuclear energy say that it takes too long to deploy.

If it takes six years to build, and you need 49 of them to replace one coal-fired station, well, would it take 294 years for them to accomplish that goal? Well, perhaps I’m being a tiny bit mendacious. You never know, perhaps they could achieve faster deployment constructing them in parallel, and maybe it would only take 200 years, or 150 years. Maybe.

Six years is in fact sufficient time to construct a nuclear power plant, if you’re serious about doing it and don’t allow it to be delayed. All the nuclear units at the Kashiwazaki-Kariwa nuclear generating station in Japan were each constructed in timescales of between three and five years; Kashiwazaki-Kariwa Unit 2 and Unit 5 both commenced construction in 1985, and both were completed by the end of 1990, within 5 years. Obviously the Japanese operators failed to see any relevance what so ever of a certain ill-fated Soviet graphite pile to their operations.

Even if you want to talk about conservative, drawn out timescales for the construction of new nuclear power in Australia, say, 10 years maybe, it’s still a far, far faster option, for a given amount of energy delivered, than solar or wind.

Written by Luke Weston

March 11, 2009 at 12:50 pm

The environmental footprints of coal and uranium mining.

This is a coal mine. Specifically, it’s the Blair Athol coal mine in central Queensland, Australia, but there’s no special reason why I chose this specific example of a coal mine. The mine produces 12 megatonnes of coal per year. (This is just a satellite image taken from Google Maps, which anybody can of course easily access.)

Coal has a thermal energy content of about 25 MJ/kg, and therefore 12 megatonnes of coal corresponds to a primary energy content of about 2.9 x 1017 J.

This is the Ranger uranium mine, near Jabiru in the Northern Territory of Australia. Again, nothing special about this specific uranium mine, it’s just an example.
All these satellite images are at a consistent scale factor, or zoom level/resolution.

In 2007-2008, Ranger produced 5273 tonnes of U3O8.

A conventional, relatively inefficient low-enriched uranium fuelled LWR with a thermal (primary energy) power output of about 3 GW requires approximately 200 tonnes of U3O8 to be mined to fuel it for one year, assuming that newly mined uranium is used for all its fuel.

Therefore, the annual uranium output from Ranger corresponds to about 2.5 x 1018 J of primary energy, or about 8.6 times the primary energy content supplied by the coal mine.

That is, that one uranium mine supplies the same amount of energy content as nine of the coal mines – one seemingly quite small uranium mine, which is about a third of the size of the coal mine, supplies the same amount of primary energy content as this. (I won’t embed that image in the post, since it will probably completely destroy the formatting of the page.)

Written by Luke Weston

January 9, 2009 at 7:24 am

Thermodynamics, stars, uranium, life and everything: Part II

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The amount of time necessary to exhaust nuclear energy provided by existing uranium deposits, unused energy in current reserves of used radioactive “waste”, heat produced by the radioactive decay of uranium, thorium and potassium deep inside the Earth (in other words, geothermal energy), and uranium in seawater could indeed last billions of years – approaching the evolution of the sun off the main sequence, and with that, the end of life on this world.

If the energy from the Sun is “renewable”, so too is nuclear energy equally every bit as renewable.

The concentration of uranium in seawater in the world ocean is about 3.3 parts per billion. The total mass of Earth’s hydrosphere is about 1.4×1021 kilograms, therefore putting the total mass of uranium in the world ocean at 4.62 billion tonnes.

Current total world demand for electricity stands at 16,330 TWh per year. Let’s conservatively suppose that, over the millennia to come, the average total world demand for electricity is four times what it is at present, or 65,320 TWh. Conventional LEU fueled light-water reactors and inefficient once-through fuel use in these reactors consume about 200 tonnes of uranium mined per gigawatt-year of electric power generation.

Hence, if we make the assumption that all the nuclear energy generation over these coming millenia is performed with this inefficient once-though LEU fuel chain and no recycling or reprocessing of nuclear fuels is performed, then the world demand for uranium can be expected to be 1.49 million tonnes per year.

Hence, consuming 1.49 million tonnes of uranium per year to supply all the world’s electricity, the 4.62 billion tonnes of uranium presently dissolved in the ocean will supply the world’s electricity for 3100 years.

$\mathrm{\frac{4.62 \times 10^{9}\ tonnes}{(200\ tonnes\ per\ GW\cdot year) \cdot (65320\ TWh/year)}\ =\ 3100\ years}$

Here we have assumed that no use is made of efficient, advanced reactors or breeder reactors and no use is made of the excess “depleted” uranium-238 or natural thorium, no deuterium is used for nuclear fusion, and no uranium is mined on land. Such assumptions are of course ridiculous, but let’s just be as conservative as possible, for argument’s sake for the purposes of this baseline, worst-case scenario.

If we considered a truly efficient efficient use of nuclear fuel, we may consider an efficient, advanced reactor such as a molten-salt reactor, efficiently transmuting uranium-238 into plutonium-239 in situ to generate energy. We may assume that 200 MeV of energy is released per fission event, and that the efficiency of the 238U transmutation and liberation of useful energy output from these nuclear processes within the reactor is, say, 75% overall. If we assume that this thermal energy is converted in a Brayton-cycle power plant with a thermodynamic efficiency of 50%, then hence we know the amount of natural uranium required to fuel the reactor.

$\mathrm{\frac{1\ GW\ \cdot\ 1\ year\ \cdot\ 238\ u\ \cdot\ 1.66 \times 10^{-24}\ grams/u}{200\ MeV\ \cdot\ 75\% \cdot\ 50\%}\ =\ 1.04\ tonnes}$

Just over one tonne of natural uranium is required, to generate one gigawatt-year of energy. (That number is basically the same if we’re looking at efficiently burning thorium in a MSR, incidentally, also.) If we utilised nuclear energy efficiently, like this, then the 4.62 billion tonnes of uranium presently dissolved in the ocean would supply the energy we discussed above, 65,320 TWh, for (just under) an astonishing 600,000 years!

$\mathrm{\frac{4.62 \times 10^{9}\ tonnes}{(1.038\ tonnes\ per\ GW\cdot year) \cdot (65320\ TWh/year)}\ =\ 597,558\ years}$

However, we are not finished yet. Elution of the uranium in the Earth’s crust into the ocean occurs on an ongoing basis, adding 3.24×104 tonnes of uranium to the ocean annually.

It was motivated by Cohen* that we could recover uranium from seawater at perhaps half of that rate; 16,000 tonnes of uranium from seawater per year. This quantity of uranium would supply 15.4 TW of electric power, if used efficiently as outlined above. In order to supply 65,320 TWh of electricity per year, four times the current worldwide demand for electricity, we only require 7750 tonnes of uranium per year, less than half that figure of 16,000 tonnes.

[* Many of you will be familiar with Cohen’s work, but if you are not, that book is highly recommended.]

Cohen argues that given the geophysical cycles of erosion, subduction and uplift, the uranium elution into the oceans would last for five billion years, at a rate of withdrawal of 6500 tonnes per year. At a rate of consumption of 7750 tonnes per year, in the absence of the use of any uranium and thorium mined on the crust, or the use of deuterium for nuclear fusion, the uranium from the oceans alone can be expected to meet world demand for electricity, at 65,320 TWh of electricity per year, for 4.2 billion years. Over a timeframe on the order of 109 years, of course, some non-trivial fraction will be lost, simply due to radioactive decay – however, at the same time, we have not even begun to consider the use of uranium and thorium reserves in the crust, or the use of the vast supply of deuterium as an energy source.

Clearly nuclear energy remains a viable resource on the Earth for a time scale of approximately five billion years – these nuclear fuels will not be consumed or depleted over a timeframe comparable to the life of the sun on the main sequence. Just as the finite hydrogen within the core of the Sun is a “renewable” energy resource, so too is the finite resource of terrestrial nuclear energy an equally renewable energy resource.

However, there is one final point we have overlooked. Even during its life in the main sequence, the Sun is evolving, as with all such stars. The Sun is gradually increasing in luminosity, by about 10% every one billion years, and its surface temperature is correspondingly slowly rising. This increase in the luminosity of the sun is such that in about one billion years, the surface temperature of the Earth will permanently have become too high for liquid water to exist, the oceans will evaporate and a catastrophe of the most immense proportions imaginable will overtake our planet. The Aztecs foretold a time `when the Earth has become tired… when the seed of Earth has ended’. All life on Earth will be extinguished, billions of years before all the nuclear fuels will be depleted.

In the meantime, our descendants will have evolved into something quite different, as far divergent from us in evolutionary terms as we are from the simplest one-celled organisms to have existed on the Earth. If they still inhabit the Earth, our descendants will leave, perhaps to Mars, or to the moons of the gas giants, Europa, perhaps, rich in water and perhaps not dissimilar to Earth if warmed up a little, or perhaps to a younger, more distant world, orbiting a younger star, around which their civilization will flourish once more.

Written by Luke Weston

October 12, 2008 at 1:12 pm

ThermoGen: When “Green” energy doesn’t add up.

I’ve been looking at some of the claims on the website of Thermogen recently.

In short, what Thermogen claim is that they can supply a domestic solar thermal energy installation whch provides an electrical power output of 5 kWe, and that that power output is accessible 24 hours a day via energy storage in tanks of high-temperature water.

The Thermogen is designed to supply it’s rated output 24 hours per day, cloudy or sunny weather e.g. a 5kW system will supply 120kW per day. [sic] It has a three day design storage for inclement weather.

Of course, if a 5 kW system can supply 5 kW of power for 24 hours, then that’s 120 kilowatt-hours of energy. I’m a little bit wary of a company selling energy technology when they can’t tell the difference between a unit of energy and a unit of power.

This heated water is then stored in 1000 litre insulated tanks at 150-200 °C. These tanks are a solar energy storage system designed to store enough energy to provide the following services for up to three days without sunshine:

For a 5 kWth system to be able to store energy up for three days, then 360 kWhth of energy must be stored in the system. We’ll come back to that in a minute.

They explain that:

Each panel measures 2.4m wide and 2m up the roof. It is expected that you will need 7 of these panels for the Thermogen system.

That’s a collector area of 33.6 m2. A little less than that, actually, since not 100% of the panel’s dimensions will be usable solar collector area.

For comparison, a standard large two-panel Solahart hot-water system has a collector area of 3.5 square metres.

Now, if we look at BOM’s map of average daily solar exposure across Australia, we see that the average daily solar exposure is, in the sunniest parts of nothern Australia, 21 megajoules of solar energy per square meter per day.

If there is one idea to keep in mind when considering solar energy, that is it. Irrespective of what sort of collector technology you have, there is always a very finite limit to the amount of energy you can collect from a solar collector of a given area. That energy flux is the maximum that there is to be utilised, no matter what technology you use to harvest it.

So, anyhow, we have 21 MJ/m2/day, and a rooftop solar collector of 33.6 m2. We’ll be conservative here and assume (a) you live in Townsville or Alice Springs or Darwin and (b) the entirety of the surface area of those collectors is active area. So, the power output that you get is a maximum of 705.6 megajoules per day.

The most efficient evacuated-tube solar thermal energy collectors, like the ones proposed by Thermogen, manage a gross efficiency of energy collection of about 60%. So, now we’re down to 423.36 MJ per day.

This thermal energy is then converted into electrical energy in a heat engine. In this case, the engine that they’ve pictured on their webpage – without attributing it’s source – is a Freepower 6 [PDF link] 6 MWe Organic Rankine Cycle powerplant.

Some of the images on the Thermogen site appear to depict the FreePower 6 organic Rankine cycle engine / generator as well as a Rotartica absorption chiller, with no credit given to the peope responsible for these components.

(An organic Rankine cycle is simply a Rankine cycle engine using an organic chemical as the engine’s working fluid, such as a fluorocarbon liquid, a fluorocarbon gas like a refrigerant type material, or some type of liquid with a lower boiling point than water, as the engine’s working fluid. Such engines are commonly used to recover low-grade heat from industrial processes, and as geothermal electricity generators, since they’re designed to operate with low temperatures.)

Now, let’s look at the specs of the FreePower 6 engine. It requires a heat source of 180 °C, returns the cooled oil at 123 °C, and requires a thermal power input of 70 kWth, to generate an electrical power output of 6 kWe. Since the Thermogen system is supposed to generate 5 kWe, I presume 1 kWe is consumed to drive the hot water pumps.

Therefore, the engine only has an efficiency of 8.6% – seemingly very low efficiency indeed. That seems like a terribly low efficiency, but the maximum efficiency – as per Carnot’s theorem – at these temperatures is only 11.6%, so the efficiency realised in practice isn’t too bad. At least these guys aren’t trying to flog off a perpetual motion machine.

Now, if we’re putting 423.36 MJ into the engine, and our electricity output is uniform day and night, then at this efficiency, we have a thermal input power of 4.9 kW, and we’re getting an electrical power output of 421.4 Watts.

I suppose that might be where they’re getting their claimed of “5 kW” from, given that they’re putting an average power of about 5 kW thermal into the engine?

Furthermore, cooling water is required to dissipate the engine’s 60 kWth of waste heat, at a flow rate of up to about 0.8 L/s and a maximum outlet temperature of 55 °C. I’m afraid that yes, in this house, we obey the laws of thermodynamics. Perhaps you need to build an artificial pond next to it or something? But that’s good, right? Lake Anna attracts lots of tourists, doesn’t it? ;)

So, we’re left with 421.4 Watts. Jump for joy; your energy needs are solved forever.
That’s, what, enough energy to run a handful of incandescent light bulbs?

We have an electricity output of 10.11 kWh per day, then.

The energy requirement for an average home is 10kW per day (See Synergy website), so the additional 110kWhrs of electricity may be supplied to the grid.

For example, a 5kW Thermogen system will generate 120kW per day while the average Australian home uses between 10kW to 30kW per day.

Average Australian household electricity consumption is about 15 GJ per household per annum – 11.4 kWh per day.

If you have a small household, or an energy-efficient household, then such an installation can realistically meet all your household electricity needs. Probably. If you live in northern Australia. If you live in Melbourne, Sydney or Adelaide, forget about it. Even if you could supply all household demand for electricity, however, there will be little or none left to sell into the grid.

They claim that the power generated from a domestic Thermogen installation “will supply a revenue stream of up to \$20,000 per annum at current rates which will pay the mortgage on most homes in Australia”.

It won’t.

If we really did want to generate 120 kWh of electricity per day, what would be required? You’d simply need 400 square meters of collector panels. That won’t fit on your roof. It would be the kind of system that lives up to what they’re claiming, though.

This is before we even start thinking about the energy storage tanks of a couple of thousand litres of water at 150 to 250 °C – superheated water at pressures exceeding 200 psi. If you’re standing around the tank and it ruptures, it will cook you to death. Do you really want this engineered and installed in homes by people who can’t tell the difference between power and energy?

For a 5 kW system to be able to store energy up for three days, then 360 kWh of energy must be stored in the system.

If the initial temperature of the water is 180 °C, and the final temperature of the water is 123 °C, then the storage of 360 kWhth to supply three days worth of energy requires 360 kWh / (4.184 Jg-1K-1 * 57 K * 1 g cm-3) = 5434 L; 6 quite large 1000 L storage tanks.

How much does all this cost, anyway? There is not one word of it on the site thus far.

There’s nothing especially malicious or ill-intentioned about Thermogen – although I would not invest in them under any circumstances. They simply appear to be another trendy, hopeful “Green” enterprise that simply can’t count.

The illustrious Dan Rutter has more in a similar vein, here.

Written by Luke Weston

October 11, 2008 at 11:55 am

“Nuclear Power Will Kill the Coal Industry”

Many reader’s will be familiar with Australia’s Construction, Forestry, Mining and Energy Union (CFMEU) and their now-slightly-infamous “nuclear energy threatens coal jobs!” position.

But could nuclear power really “kill the coal industry” in Australia? I don’t think so.

Total production of raw black coal in Australia in 2006 was 405 Mt (million tonnes). This production represented a small increase of 1.6% over the 2005 figure of 399 Mt. After processing, a total of 317 Mt of metallurgical and thermal black coal were available for both domestic use and export in 2006.
(I’ve taken these statistics from the Australian Coal Association website.)

In 2006, Australia’s domestic consumption of black coal for electricity generation amounted to 62.4 million tonnes of black coal. Hence, domestic electricity generators consume only about 20% of Australia’s output of processed black coal. Other domestic industrial uses of coal, such as steel production, account for about three percent, with the entire remaining 77% being exported.

(The ACA’s statistics refer exclusively to black coal – however, brown coal is a much smaller resource, relatively, and since we have the statistics for black coal, I’ll limit the discussion to black coal.)

Hence, under the worst case scenario (or best case scenario), we may envisage a future in which every coal-fired generator in Australia is closed down and replaced by nuclear power plants. This would result in cutting Australia’s greenhouse gas emissions in half – at the cost of a 20% reduction in coal demand. If we were to see half of Australia’s coal fired plants closed down and replaced by nuclear energy, we will see a 10% reduction in coal revenue.

I don’t think a 10% to 20% downturn in revenue constitutes “killing the coal industry” – and I really don’t think that the coal industry has anything to worry about for the foreseeable future.

Written by Luke Weston

August 31, 2008 at 8:48 am

Australian support for consideration of nuclear energy continues to grow.

Paul Howes, national secretary of the Australian Workers’ Union, is continuing to advocate taking a reasonable look at the role of nuclear energy as a means to achieve anthropogenic GHG emissions reductions. As you might expect from Australia’s largest trade union, their chief area of concern is the mitigation of GHG emissions, and the introduction of GHG emissions trading, without damage to Australian industries and industrial employment.

THE Rudd Government is being urged to embrace nuclear power as a source of clean energy, amid warnings its emissions trading scheme could result in desolating Australian mineral and metallurgy industries.

Just days before the Government releases a discussion paper on carbon trading, a new report shows Australia’s aluminium industry – employing 35,000 people – could be devastated.

Challenging Professor Ross Garnaut’s preferred model, the Australian Workers’ Union wants the key metals sector to receive a partial reprieve from carbon trading.

The union has a powerful ally: respected business figure and Commonwealth Bank chairman John Schubert.

Mr Schubert, who also chairs the Great Barrier Reef Foundation, says Canberra should “definitely look at” nuclear power.

It needs to be a real option… should absolutely be on the table“, Mr Schubert said.

Howes has just released a report from Per Capita consulting on the effects of the emissions trading scheme on Australian industry – specifically the aluminium industry, in this case.

It says the future for the aluminium industry is grim if the Government gets the design of an ETS wrong.

Union and business leaders fear an ETS will cause job losses and send investment offshore, with the aluminium industry particularly vulnerable.

The Per Capita report says jobs could be lost to Brazil, China and India if Canberra imposes tough new laws.

The study recommends the Government give the aluminium industry a “partial exemption” from carbon trading for up to five years and embrace nuclear power.

Mr Howes said the report would bring a “bit of level-headedness” to the debate over emissions trading and climate change.

Mr Howes said he was sick of hearing claims that workers in “heavy-polluting” industries, such as steel and aluminium, could be re-trained in “green” industries.

Instead, workers could be “left on the scrapheap of history” and enter the ranks of the long-term unemployed, Howes claims.

Personally, I don’t agree with the popular conception that aluminium production is an especially highly GHG emissions intensive industry.

Direct GHG emissions intensity for aluminium production in Australia was 2.0 tonnes CO2-e per tonne of aluminium production in 2007 — down from 2.1 in 2006 and 5.0 in 1990 — an improvement over the 1990 level of 60 per cent.

Indirect GHG emissions intensity from electricity consumption for aluminium production remained at the same level as 2006 at 14.1 tonnes CO2-e per tonne of aluminium production — down from 16.1 in 1990 — an improvement of 12%. This reflects both energy efficiency and changes in greenhouse grid factors.

Australian aluminium production in 2007 (i.e. aluminium smelting, not alumina production) contributed 31.6 mt (million tonnes) of GHG emissions (CO2-e), comprising 3.95 mt CO2-e of direct PFC emissions, direct carbon dioxide process emissions and other site-level emissions, and 27.69 mt CO2-e of indirect emissions from electricity consumption.

The Australian aluminium smelting industry consumed 29,500 GWh of electricity in 2007, corresponding to an average GHG emissions intensity of 939 g/kWhe for the electricity consumed by Australia’s aluminium smelters – consistent with Australia’s extremely GHG intensive, overwhelmingly coal based electricity generation capacity.

[These statistics are taken from the Australian Aluminium Council’s 2007 Sustainability Report.]

Indirect GHG emissions from fossil fuel electricity generation – which aren’t really emissions from the aluminium production industry at all – hence comprise 88 percent of the GHG emissions intensity ascribed to the aluminium smelting industry.

If the overall GHG emissions intensity of the electricity supply of 939 g/kWhe was cut to, say, 100 g/kWhe through the replacement of coal fired generators with nuclear energy, geothermal, solar thermal, hydroelectricity or what have you, then the greenhouse gas emissions of aluminium production in Australia can be cut from 31.6 mt to 6.9 mt – 3.52 tonnes CO2-e per tonne Al, compared with 16.1 tonnes CO2-e per tonne Al at present – a 78% reduction in greenhouse gas emissions intensity, and that’s on top of any further improvement in energy efficiency and/or process efficiency, PFC emissions reduction and so forth, in the industry.

Aluminium smelters are not at all the cause for concern here. The burning of coal and fossil fuel for essentially all the country’s electricity generation is by far the foremost concern that we need to address.

The AWU’s press release, and the 32 page analysis commissioned by the AWU from Per Capita, are available here.

Also, in Canberra today, economist Professor Jeffrey Sachs warns that the world must embrace nuclear power as one of its options if it is going to win the fight against the potentially catastrophic damage of anthropogenic greenhouse effect forcing.

Professor Sachs, director of the Earth Institute at Columbia University and author of the book The End of Poverty, warned that global warming had the potential to undo the progress being made in the war on global poverty, making the tropics hotter and arid regions even more arid.

In Canberra to give a keynote speech today at the Australian National University’s annual China Update, he said the world would need to use every available technology – and develop some more – to reduce anthropogenic greenhouse forcing at the same time as rapidly expanding its output.

Professor Sachs, who has not supported nuclear power in the past, said better technology was the key to breaking the link between economic growth and carbon dioxide emissions, and the world could not afford to do without either nuclear power or cleaner coal.

“I support the reintroduction of nuclear power”, he said. “It’s hard to see how we’re going to get enough energy with low carbon emissions without nuclear playing a significant role.

If Australia chooses not to go that way, it’s going to have to go even more aggressively towards solar energy and carbon capture and storage. My own feeling is that nuclear is safe and cost-effective.

Professor Sachs, 52, played a key role in drawing up the Millennium Development Goals that are the targets for reducing global poverty.

Yesterday he said climate change was one cause of the steep rise in world food prices, which is making food unaffordable in some poorer areas.

If the world can not afford to do without either nuclear power or “cleaner coal”, and nuclear power is already a developed, mature, proven technology across the world, and “cleaner coal” is far from it, then it’s not much of a contest, is it?

Written by Luke Weston

July 14, 2008 at 5:12 pm

Genepax “Water Energy System”: Redux

An update on the latest “breakthrough car that runs on water!”:

http://techon.nikkeibp.co.jp/english/NEWS_EN/20080616/153301/

Kiyoshi Hirasawa, president of Genepax Co Ltd, unveiled part of the reaction mechanism of the company’s new fuel cell system called “Water Energy System” in an interview with Nikkei Electronics.

The system, which is capable of generating power with water and air, was first presented June 12, 2008. As reported in our previous article, the system produces hydrogen through a chemical reaction between water and a metal (or a metal compound) on the fuel electrode side (See related article).

Genepax uses a metal or a metal compound that can cause an oxidation reaction with water at room temperature, the company said. Metals that react with water include lithium, sodium, magnesium, potassium and calcium. The main feature of the Water Energy System is that it can be operated for a longer period of time by controlling the reaction of the metal or the metal compound, the company said.

According to Genepax, the metal or the metal compound is supported by a porous body such as zeolite inside the fuel electrode of the membrane electrode assembly (MEA). The products of the hydrogen generation reaction dissolves in water, and the water containing them will be discharged with water inside the system. Upon the completion of the reaction, the generation of hydrogen and power stops.

There is nothing revolutionary here – nothing that violates the laws of physics. Rather than “running on water” the device if fuelled with chemical potential energy in the form of a reactive chemical – such as lithium metal – that will spontaneously reduce water to hydrogen gas on contact, consuming the lithium. Energy is “stored” in such a material, which requires considerable energy input to create, and does not occur in the free metallic form in nature.

This is essentially nothing more than a non-rechargeable chemical battery. When its chemical “fuel” is depleted, it doesn’t work, and the chemical material must be replenished.

Written by Luke Weston

July 14, 2008 at 5:21 am