David Archibald

Introduction

There was an inspiring story in the magazine Tablet about Palmer Luckey, the founder of the first-person-viewer company bought out by Meta. As recounted in Tablet, Mr Luckey had an epiphany – instead of developing the next iteration in that technology, he should develop the ultimate technology. He did, made billions and went on to found a yet more successful company in defence technology.

So that begs the question: what is the ultimate technology in energy? What technology will our great grandchildren have settled on to keep the lights on, the wheels turning and the grain growing? No matter what we are doing in energy at the moment, we, as a civilisation, should prepare for adopting the ultimate technology. Preparation starting as soon as possible will reduce the pain and suffering in getting to that shining city on a hill.

That choice won’t be between wind and solar, on one hand, and fossil fuels on the other. The fossil fuels will largely be exhausted in three generations so they won’t be part of the solution. And believe it or not, wind and solar won’t be part of the solution either.

The reason for that is that you can’t make wind turbines and solar panels with power produced from wind turbines and solar panels. Those things are artefacts of currently cheap Chinese coal prices. In fact, polysilicon production in China for making solar panels has moved 3,000 km inland to the province of Xinjiang where the coal and the Uigher slave labour are cheapest.

Power in China at US$0.05/kWh makes solar panels which, under the most ideal conditions on the planet – supplying gold mines out the Australian desert, produces power at the price of power from diesel at US$0.20/kWh. So, if you used power from solar panels at US$0.20/kWh to make solar panels, what would the cost of power from that second generation of solar panels be? It is likely to be of the order of US$0.80/kWh and so on to infinity. That ignores the lubricating effect of oil as a high energy-density liquid fuel in keeping industry going.

Wind turbines and solar panels are neither renewable or sustainable. Solar panels only last 15 to 20 years. And then what? They are mostly glass and not worth more than empty beer bottles. Will the metals smeared on them as thinly as possible be worth recovering? Nobody has bothered to do so yet and likely never will. There goes the renewable label. What is worse is that the metals used to make solar panels include cadmium. Cadmium is more poisonous than lead. It is highly toxic when ingested or inhaled, primarily affecting the kidneys, bones, and lungs. Inhalation of cadmium dust or fumes is particularly dangerous and can lead to lung cancer. Cadmium can accumulate in the environment, especially in soil and water. It is taken up by plants, entering the food chain and potentially impacting human health through contaminated food. Cadmium loading is up to 10 grams per square metre of solar panel. To avoid environmental damage, solar panels will have to end up in engineered repositories. There is nothing renewable, sustainable, economical, rational or joyous about solar panels.

It is the same for wind. Wind turbines are engineered to last as long as the power contract they are to service. Why design for a 50 to 100 year life if your contract is for only 15 years? Blade failure is one thing and rotor fires are understandable but the fact that the towers of wind turbines buckle means that they are built on the slimmest of design margins. If we paid 20% more for our wind turbines, would they last five times as long? We are told to think of the children, but our grandchildren won’t inherit these things. What they will inherit is a lot of waste fibreglass to send to landfill.

Let’s cut to the chase. If wind turbines and solar panels are just self-indulgent artefacts of currently cheap Chinese coal power and the fossil fuels will fade due to depletion, what is the choice of energy systems for our great grandchildren? It is a choice of either nuclear energy or horse-drawn carts. Let’s assume that they make the better choice of nuclear power. That may seem to be the better choice but we now live in a world in which some politicians can’t define what a woman is and that inability seems to be no impediment to their re-election. So sensible choices can’t be taken for granted.

Figure 1: The energy transition from fossil fuels to nuclear was predicted 68 years ago

From King Hubbert’s 1956 paper Nuclear Energy and the Fossil Fuels.

It won’t be nuclear power as it is commonly understood, which is U²³⁵-burning light water reactors. Apart from safety considerations of having water and zirconium in the same reactor vessel, and the enormous spent fuel legacy, that technology is dreadfully wasteful as it uses only about one percent of the energy contained in uranium as it is dug out of the ground. Why we have light water reactors as the dominant nuclear technology is a consequence of what came first. What came first was nuclear submarines with the launch of the USS Nautilus in 1954. The authorities in the US wanted to develop the nuclear power sector and the fastest way to do that was to repurpose the reactors from the US nuclear submarine fleet. Little has been done to switch to better technology in the last 70 years.

The big two things in nuclear power, which nobody on either side of the argument seems to talk about, are high level waste and delayed fission reactions. Current practice for all current commercial reactors in the US is for the used fuel rods to be put in pools of water for a few years to cool down, in a radioactivity sense, and then be placed in steel casks for decades. Recycling would cost about US$2,000 per kg of used fuel which is higher than the cost of mining and enriching uranium out of the ground.

It is a bad thing that our generation is not bearing the burden of recycling those used fuel rods to recover the energy that is inherent in them. In the US that is currently 90,000 tonnes and rising at 2,000 tonnes per annum. On the other hand, at some point the cost of mining uranium will rise above the cost of recycling and our descendants then will inherit a blessing of hundreds of thousands of tonnes of energy-dense fuel.

The other big thing about nuclear reactors to bear in mind is that at steady state, 7% of the energy is coming from delayed fission reactions. That is from atoms that have absorbed a neutron but have not split immediately. They will split and generate heat. And if that heat can’t be handled, bad things can happen. One of the worst things that could happen is if the zirconium cladding of the fuel rods heats up to1,250°C and then reacts with water to produce hydrogen. The hydrogen accumulates and then explodes. All three of the operating reactors of the Fukushima power plant had hydrogen explosions.

Figure 2: Fukushima reactor explosion timeline

Even worse is if the fuel rods melt together and then that mass melts through the reactor shielding to the concrete floor underneath and then keeps going. The big, hot, sticky, intensely radioactive mass is called corium. Some reactors have a special chamber to catch the corium. It would be better not to have the possibility of a meltdown in the first place.

All these problems – the squandering of 99% of the contained energy of mined uranium, the burden of high-level waste and the danger from delayed fission reactions – are all solved by adopting the best nuclear technology possible which is plutonium breeder reactors.

The Leaving of Oil

Before we discuss that best of all possible worlds, let’s go back to what made it achievable – fossil fuels as the bridge between burning wood and breeding plutonium. Fossil fuels allowed civilisation to develop to a high level and showed us what was possible. Fossil fuels allowed us to light the nuclear match that started the fire that will sustain civilisation at a high level for all of eternity. But, unlike nuclear, fossil fuels aren’t forever and to avoid pain and suffering, we have to leave fossil fuels faster than they leave us.

World oil and condensate production peaked in November 2018 at 84.6 million barrels per day with the United States, Russia and Saudi Arabia each contributing a bit over 11 million barrels per day. Peak world oil production had been predicted for 2005 but the development of the US tight oil industry delayed that by 13 years. In fact, US oil production has continued to rise to 13.2 million barrels per day in late 2024 while non-US production fell by six million barrels per day. But new oil discoveries are only a fraction of what is produced annually. In 2023, oil discoveries amount to 2.6 billion barrels while annual production was 37 billion barrels – 14 times as much. Exhaustion is inevitable. It is just a question of what the decline profile will look like.

Figure 3: US tight oil production by year of well drilled

US oil tight oil production is a treadmill. If drilling stopped overnight, production would halve within 18 months. The rig count for drilling horizontal oil wells in the US is currently in downtrend which means that drilling for tight oil is breakeven at best at the current oil price. The combination of these factors means that the oil price is underwritten by the lack of highly profitable locations to drill. A further factor is that the quality of the remaining locations continues to fall as the best locations have been drilled first, meaning that a higher oil price will be required for them to be drilled.

Figure 4: Texas Railroad Commission District 8 Oil Production January 2021 – July 2024

Texas District 8 is in the core of the Permian Basin in which the most profitable well locations were drilled first. Production peaked in late 2023 and by July 2024 had fallen by 700,000 BOPD. This rapid decline in production in the core of the basin indicates that production has peaked. It also means that a higher oil price is necessary to slow the production decline.

Figure 5: Lea County Gas Oil Ratio relative to production

Oil production from tight oil wells falls once the reservoir pressure declines to the bubble point at which natural gas comes out of solution and starts moving towards the well bore. The more that reservoir pressure declines, the greater the rate of gas production and the faster the pressure decline, leaving oil in the formation and preferentially producing gas.

The fastest part of the decline will come from the US tight oil segment. In the unconstrained extraction of a resource, production declines, and costs go up, once half of the initial resource has been extracted. The increasing gas to oil ratio in the prime oil counties of the Permian Basin suggest that has now happened. So much gas is being produced now in parts of Texas that the natural gas price can be negative locally.

Figure 6: The major US tight oil basins production profile

What of natural gas? Currently it is much cheaper than oil on an energy content basis but when the oil price rises due to declining supply, methane is the next best alternative and will go to the oil price on an energy content basis. This has already happened on the international LNG market.

It is said that natural gas is essential to glue the solar and wind power grids together and that is true. Which in effect means that you are using a hydrocarbon priced at the oil price to provide power. If that power ends up being used in an electric vehicle, then 29% of the energy contained in the natural gas ends up as power to the wheels. Natural gas can be used directly in internal combustion engines in which case 40% of the contained energy ends up as power to the wheels. Iran and Pakistan have a high proportion of their vehicle fleets running on natural gas.

One of the more amusing political phenomena of recent times is the campaign against using natural gas for cooking. The globalists would rather we cooked our insect protein ration on a single plate induction cooktop. The transfer of the contained energy from natural gas to the food being cooked is 90% on a gas stove. Using an electric stove lowers that to 36% – less than half. If you wanted to lower domestic energy consumption, you wouldn’t discourage cooking using natural gas. Unfortunately the same people trying to ban gas stoves, and thus more than doubling energy consumption in the process, are also making rules and regulations on far more important matters.

If the haters amongst us despise natural gas because of the single carbon atom in the methane molecule, what do they think of coal in which the molecules can include thousands of carbon atoms? It doesn’t matter because all the coal that can be economically dug up and burnt will eventually be dug up and burnt. But not for power generation. The last research into coal liquefaction in Australia was conducted by a Japanese group in the Yallourn Valley in the early 1990s. They determined that the brown coals of Victoria were quite amenable to liquefaction by the Bergius process and that the oil price required for commerciality was then US$40 per barrel. US$40 per barrel then is now US$110 per barrel. As oil production tips over into decline, that price will be with us soon enough.

Figure 7: Bergius Process mass balance from Bergius’ 1931 Nobel Prize acceptance speech.

Our coal reserves shouldn’t be seen as something destined for power generation. Once the oil price goes through US$110 per barrel, coal will go to the price of oil less the capital and operating costs of the conversion process. In fact there is a role for nuclear in all this. All the Bergius plants operated to date, including the ones recently built in China, generate the hydrogen needed for the hydrogenation step by processing part of the product stream in a steam reformer. The step is 40% of the capital cost of the plant and consumes 20% of the energy in the coal feedstock. In a more perfect world, the requisite hydrogen would by produced by electrolysis using power produced by nuclear reactors.  This would also make the plant much easier to operate by decoupling hydrogen production from the process stream.

Figure 8: Bergius Process Using Nuclear Power for Hydrogen generation

Synthetic liquid fuel production using coal as the feedstock and powered by nuclear energy will be the next big thing. Diesel molecules are 13% hydrogen by weight and 87% carbon. In energy content terms, they are 39% hydrogen and 61% carbon. Carbon is in effect the carrier allowing hydrogen gas to be liquified and made into something useful. For all the hydrogen enthusiasts, synthetic fuel production via the Bergius process will be the closest we will come to a hydrogen economy. Hydrogen enthusiasts they should reconcile themselves to this fact.

Figure 9: Diesel’s components by weight and energy contribution

Once the coal runs out, the Bergius plants will have to switch to consuming wood and other biomass as the carbon source. That is why the title of this paper is Conserve to Convert. If we were a sensible species, we would be replacing our coal-fired power stations with nuclear ones. Nuclear will always be with us but when the coal runs out, our standard of living will be dependent, to a large extent, on the cost of carbon from biomass.

Figure 10: Australian per capita carbon consumption by application

Energy Price Equivalence by Source

The fossil fuels no longer in overabundance on world markets are oil and natural gas (as LNG) and are now in price equivalence in energy content terms. To provide a guide to what will happen to the prices of the energy sources that can substitute for oil when they go to price equilibrium with oil, the following table was constructed:

Table 1: Price equivalence of energy sources with oil.

The early history of the oil industry was over-abundance. So much oil was found in Texas early last century that the Texas Railroad Commission was given the role of controlling oil production in the state in 1919. Then the US became a net oil importer in 1950 and the locus of production shifted to the giant oilfields of the Middle East. Control of the oil market shifted to OPEC after the Yom Kippur War of 1973. Once again, OPEC’s role was to limit production to keep the price up. The world started consuming more oil than was discovered each year in the 1960s and so from there it was only a matter of time before production peaked and then tipped over into decline.

In 1956, Shell geologist King Hubbert had predicted that US oil production would peak in 1970, which it duly did. There was an expectation that world oil production would peak in 2005. That was also the time a number of LNG receiving terminals were proposed in the US as it was expected that the US would start running short of natural gas too. Then the US shale oil and shale gas phenomenon started. The US has provided all the growth in world oil production over the last 20 years. The US LNG import terminals were repurposed to be LNG export facilities.

World oil production peaked in November 2018. Oil will become scarcer year by year. As the oil price goes up, other energy sources will substitute for it. This has happened before in the US. In the second half of the 20^th century, natural gas traded at the No 2 fuel oil price as there was a natural gas shortage, oil was cheap and manufacturers were indifferent to which energy source they used. At the moment there is such an abundance of natural gas in Texas as a byproduct of tight oil production that the wellhead price can be negative in places. The current Henry Hub price is US$2.72 per thousand cubic feet (close to a gigajoule (gj) in energy content). In terms of energy content, six thousand cubic feet of natural gas equates to one barrel of oil. So the Henry Hub price is equivalent to US$16.32 per barrel of oil in energy content terms. This is one fifth the oil price.

Figure 11: Relative energy price equivalence at current commodity prices

Natural gas can substitute for oil in a number of transport applications. Consider that a major use for natural gas now is to provide the glue that holds power grids together in the face of the inherent volatility of solar and wind as power sources.

There are signs that the heart of the sweet spot of tight oil production in the Permian Basin of Texas has tipped over into decline. The other major source of natural gas in the US, the Marcellus Shale in Pennsylvania, has now produced half of its initial resource and so should also tip over into decline concurrently with the Permian Basin. The period of cheap natural gas is about to end and natural gas, being the closest substitute for oil, will go to the oil price in energy equivalent terms. It follows that burning natural gas to keep the power grid stable will, for consumers, have the price effect of burning oil for that purpose.

Next on the substitution list for oil is coal. Oil’s price premium is due to the fact that it is a high energy-density liquid which is easy to store, transport and consume. Turning coal into synthetic liquid fuels isn’t difficult. Germany developed two processes to that end over a century ago – Fischer-Tropsch and the Bergius process. In the former, coal is burnt in pure oxygen to produce a synthesis gas with part of that being steam-reformed to produce hydrogen. The mixture of carbon monoxide and hydrogen is then catalysed in an oil bath to make liquid hydrocarbons. In the Bergius process, hydrogen is forced into coal molecules at 250 atmospheres and 300°C. The hydrogen is produced by steam reforming the methane portion of the process stream. The South African synthetic fuel industry runs on the Fisher-Tropsch process while the Chinese synthetic liquid fuel industry uses the Bergius process.

Current world oil consumption is nearly equivalent to the world’s coal consumption in energy content terms. So as oil production declines to zero, coal consumption will double, all other things being equal. What will happen is that coal will become too expensive for power generation and will be replaced by nuclear. Beyond Australia’s black coal and lignite reserves, there is a lot of oil shale in the Toolebuc Formation of western Queensland. Current retort technology to produce oil from oil shale has a low yield from the contained kerogen. If, instead, the oil shale could be hydrogenated as per the Bergius process, perhaps twice as much might be produced.

The power price per kWh in the table is the cost of power as if oil was the energy source.

Next is uranium. This is the uranium price which you would pay to have power produced at the oil price equivalent. The prices calculated are well in excess of the current yellowcake price of about US$80/lb. Last decade yellowcake was less than half that price. In energy content terms, the current yellowcake price equates to an oil price of US$15/bbl.  Most of the current cost of power from nuclear plants is depreciation – paying off the cost of building the plant. The cost of uranium is usually not mentioned as a factor and it hasn’t been a factor in the cost of running nuclear plants.

For completeness, the cost of hydrogen is included. Power at $0.05 per kWh will produce hydrogen at $7 per kg. In turn, hydrogen at $7 per kg equates to diesel at about $2.20 per litre. Which happens to be what a lot of people in Australia are paying at the pump now. The implication is that if we can keep the cost of power down to $0.05 per kWh, we can run our civilisation at a high level for all of eternity. That is the promise of nuclear.

When we have dug up all the fossil fuels and burnt them, we will still need a source of carbon. About 4% of oil production is used for making plastics, resins, pharmaceuticals and a myriad of other things. Carbon will be needed for smelting iron ore. The last hydrogen-based iron reduction plant, BHP’s Port Hedland hot briquetted iron plant, had an explosion in 2004 which killed one employee and injured two others. Hydrogen is so dangerous to handle that one of the companies making valves for hydrogen tests them by using helium rather than hydrogen. The only source of carbon will be biomass. So the table above includes the value of hardwood chips being put through a Bergius plant to produce synthetic diesel.

Wood is half carbon, 6% hydrogen and 44% oxygen. Under Bergius process conditions, wood decomposes to liberate a lot of carbon dioxide exothermically. What remains would yield three barrels of synthetic fuel per tonne of wood used. The calculated value of hardwood chips via the Bergius process at an oil price of US$100 per barrel is about the current woodchip price.

The Optimum Nuclear Technology

Apart from the considerations of safety and the disposal of high-level waste, the current dominant nuclear technology is also inherently wasteful. To power most of the world’s reactor fleet, uranium is enriched from 0.7% U²³⁵ to 3.5% U²³⁵ with the balance of 86% discarded. This discarded uranium is 99.8% U²³⁸ and 0.2% U²³⁵. Which means that 86% of the inherent energy in uranium is thrown away straight up. Current practice in most of the world is also to not reprocess the used fuel rods with the result that a further 13.75% is wasted. That is shown in the following figure:

Figure 12: Uranium light water reactor route

To produce one gigawatt of electric power requires the fission of one tonne of uranium or plutonium. Thorium is fertile, not fissile. It requires irradiation with neutrons to convert to U²³³ which is fissile. To fission one tonne of uranium in light water reactors, you start with 250 tonnes of uranium as dug out of the ground and concentrate the U²³⁵ portion to be made into fuel rods. The rods are operated down to 1.7% fissile material, equal parts U²³⁵ and plutonium. By the time the rods are pulled in a commercial reactor, the plutonium in them is 80% Pu²³⁹ and 20% Pu²⁴⁰ which makes it useless for nuclear weapons. Weapons grade plutonium has a maximum Pu²⁴⁰   content of 7%. Pu²⁴⁰ has a high rate of spontaneous fission which makes a nuclear weapon detonate too early and produce a fizzle. It also makes the cores of nuclear weapons hot, some as hot as 200°C which cooks the chemical explosives and electronics. To make weapons-grade plutonium requires more frequent reprocessing of the fuel rods.

President Carter banned the reprocessing of spent fuel rods in 1977 as a precaution against nuclear weapons proliferation. He needn’t have bothered. You can’t make nuclear weapons using plutonium you have extracted from spent fuel rods from commercial reactors.

Only one quarter of one percent of the energy inherent in as-mined uranium is used with the rest discarded. Beyond the world’s 17 million tonnes of uranium reserves, there is four times as much thorium which, like U²³⁸, is fertile, not fissile. So, in effect, the current dominant nuclear power generation technology of U²³⁵-burning light water reactors is only using 0.05% of humanity’s endowment of nuclear fuel. To access the balance requires the adoption of breeder reactors. These produces more fuel than they consume.

What the sequence would be for breeding from thorium is shown in the following figure:

Figure 13: Thorium Process Route

To breed thorium requires operating in the thermal neutron spectrum and has a maximum theoretical breeding margin of 8%. To breed U²³⁸ to plutonium requires operating in the fast neutron spectrum and therefore uses sodium as the coolant. It has a maximum breeding margin of 30%. Plutonium breeder reactors have been operating successfully for decades, mostly in Russia.

A thorium breeder reactor at commercial scale has yet to be developed. The neutron economy of a commercial design may be marginal due to things such as the neutron absorption characteristics of construction materials in the trade-off for long reactor life. This may mean that a commercial design would need help from excess neutrons produced by plutonium breeder reactors. This harks back to the fuel used for the first commercial nuclear reactor at the Shippingport Atomic Power Station in Beaver County, Pennsylvania. That fuel included thorium to breed to U²³³. In our nuclear future, no neutron should be wasted if it could be used instead to breed thorium to fissile fuel.

That reactor, and nuclear fuel cycle, hasn’t been designed yet. But we can build stepping stones to that ideal future. The best available reactors are the ARC-100 designed by Advanced Reactor Concepts to produce 100 MWe and the PRISM (Power Reactor Innovative Small Module) designed by GE-Hitachi to produce 311 Mwe.

The ARC-100 is a sodium-cooled reactor in the fast neutron spectrum. It is a modest five-times scale up of the Experimental Breeder Reactor-II (EBR-II) which operated at the Argonne National Laboratory in Idaho from 1965 to 1994.  As with EBR-II, the ARC-100 is a breeder-reactor power plant with on-site reprocessing of solid metallic fuel. In the event of a cooling pump failure, the EBR-II demonstrated the ability to elf-cool its fuel through natural convection of the sodium coolant during the decay heat period following shutdown. The fuel loading is 24 tonnes at up to 15.5% fissile material. The fuelling interval is 20 years with a plant life of 60 years.

Figure 14: ARC-100 cross section showing the hot and cold sodium pools

The ARC-100 has a capital cost of US$550 million and produces power at US$0.055 per kWh. It can be in production within three years of starting construction. The reactor vessel is 16.8 metres high with a diameter of 7.6 metres. As such it would easily be made in a South Korean factory, shipped down to Australia and then trucked to site.

GE-Hitachi’s PRISM reactor is also derived from the EBR-II, but possibly more flexible in fuel types and with a breeding margin of up to 20%. It can operate as a breeder or a burner depending on fuel choices and operational goals. Electrical output is 311 MWe per module with two modules in a power block for a total of 622 MWe. For a dual reactor configuration, the capital cost is likely to be of the order of US$2,000 million.

We know what is necessary to be done. The next question is can the nuclear transition happen as fast as it needs to happen?

Figure 15: Electricity production by source, France 1960 to 2015

Over a 10 year period starting in the mid-1970s, France was able to increase the nuclear share of its electric power production from by 70%. That was 50 years ago. With the advances in materials and electronics since, we should be able to do it faster.

With the price of coal rising towards the oil price, Australian industry will rapidly lose its competitiveness. And as our competitiveness shrinks, our standard of living will fall. As well as King Hubbert, there was another energy prophet in the 1950s. Hyman Rickover, the father of the US nuclear submarine fleet, in a 1957 address to the Minnesota State Medical Association:

“A reduction of per capita energy consumption has always in the past led to a decline in civilization and a reversion to a more primitive way of life.”

“When a low-energy society comes in contact with a high-energy society, the advantage always lies with the latter.”

“If we start to plan now, we may be able to achieve the requisite level of scientific and engineering knowledge before our fossil fuel reserves give out, but the margin of safety is not large.”

Which begs the question of what China, the major aggressor in the world, is doing in energy. China has boosted its domestic coal production to 4.7 billion tonnes per annum as well as importing another 500 million tonnes per annum. It is the world’s largest importer of oil. It produces synthetic petrol and diesel from Bergius plants in Inner Mongolia. Recently it announced the spending of US$24 billion to build synthetic fuel plants in the far western province of Xinjiang. As well as conducting a big buildout of its nuclear power reactor fleet, China is also building a couple of reactors to make weapons grade plutonium for a quintupling of its nuclear weapon stockpile from 300 warheads to at least 1,500. The purpose of the two new reactors is to make the weapons to coerce us into doing what they tell us to do, or killing us with them. Discussion of the morality of anything we might do in energy should take these facts into consideration.

Figure 16: Reactors for breeding weapons-grade plutonium under construction on Changbiao Island, Fujian Province in 2022

The Four Pillars of Civilisation

Figure 17: Australian per capita carbon consumption by application

Diesel is the first pillar of civilisation; the other three are plastics, cement, and steel.

Under optimum growing conditions in Brazil, eucalypt plantations produce 40 cubic metres/hectare per annum, which becomes 20 tonnes of dried wood. This in turn converts to 10 tonnes of lignin, which would yield 10,000 litres of liquid fuel. Assuming in Australian conditions that the yield per hectare is 25 cubic metres per hectare, one hectare would produce 39 barrels per annum of diesel per annum. To supply Australia’s requirement of one million barrels per day would require close to 10 million hectares of plantation forests — about 8% of Australia’s forested area.

In the world when fossil fuels have run out, plastics will be produced from the carbon and hydrogen in wood. Some four per cent of world oil production goes into making plastics. Assuming the same ratio holds in the post-fossil fuel world, this will be supplied by wood equivalent to four per cent of the wood used in making diesel. So for Australia this will be produced by an extra 4,000 sq km of plantation forest.

With respect to cement, Australia consumes nine million tonnes per annum. The making of a tonne of cement consumes 200 kg of coal. In the post-fossil fuel world, energy for cement making will come from charcoal produced from plantation eucalypts or power from nuclear reactors. If it is the charcoal route, the yield from wood to charcoal is 35%, so nine million tonnes of cement will be made using charcoal from 5.4 million tonnes of wood produced from 2,160 sq km of plantation eucalypts. The alternate route would involve plasma heating of an air stream up the cement kiln with the stream simply recirculated and reheated.

Smelting of iron ore to liquid iron takes about ten times as much energy as melting scrap steel in an electric arc furnace. Steel production may be two thirds from iron ore and one third from steel scrap to produce lower grades such as reinforcing bar. As such, energy consumption in the latter route is negligible. Australia consumes some 300 kg per capita of steel so let’s assume that includes 200 kg per capita from the blast furnace route. Coke consumption in a blast furnace is 500 kg per tonne of steel produced. To replace that with charcoal produced from wood would require 1.5 tonnes of wood from 0.06 hectares of plantation forestry. At the national level this will require 15,000 square kilometres of plantation forestry.

The blast furnace route is unlikey to work though, due to the fact that charcoal doesn’t have much compressive strength and so can’t support the weight of a big column of iron ore in a blast furnace. Smelting is likely to switch to electric arc furnaces with charcoal used as the reductant but with the energy to drive the smelting provided by the electric current.

David Archibald is the author of American Gripen: The Solution to the F-35 Nightmare