One of the first scientific facts most of us learned at primary school is that water is made of two gases – two parts hydrogen and one part oxygen – something that is either a revelation or seems so unlikely that it endows you with a deep suspicion of science. Perhaps this explains the attitudes of some parliamentarians. For those, however, to whom this was a revelation, it will have led to the question, who on earth was clever enough to discover this?
In fact, as early as the mid-17th century, several scientists, including Robert Boyle, one of the founders of the Royal Society, had found an inflammable gas that could be made by treating metals with acid. However, the probably autistic Henry Cavendish, after whom the famous laboratory in Cambridge was named, carried out the important early experiments in the mid-18th century. He showed that this gas was much lighter than air and that when it was burnt in air water was produced. James Watt came to the same conclusion around the same time and Lavoisier, following up these experiments in 1783, named the gas hydrogen
, from the Greek for water producer
France in the late 18th centuries equalled Britain in science, despite its habitual warfare with the rest of Europe and the awfulness of the Revolution, which must have made life there feel like Afghanistan today. Lavoisier knew of Cavendish's contributions and made the crucial reverse experiment that proved water did indeed comprise hydrogen and oxygen. He passed steam through the heated barrel of a musket and isolated the inflammable gas from the end of it. The iron of the barrel took oxygen from the water and was converted into iron oxide, leaving hydrogen gas.
This was in a period when the French military was investigating the possible value of balloons, initially raised by hot air, for spying out enemy formations and Lavoisier became involved in the commercial production of hydrogen. This led to upscaling of the laboratory process, passing steam through a cylinder containing iron filings in order to produce enough to fill large balloons. Despite his efforts in science, Lavoisier fell victim of Robespierre and the Terror, and was guillotined in 1794.
The first human flight in a hydrogen balloon was in 1783 by Jacques Charles (for whom the law of gaseous expansion on heating was later named). Hydrogen was used to lift and transport people in balloons, and later in powered zeppelins, one of which circumnavigated the world in 1929. The well-known Hindenburg conflagration in 1937, captured on an early newsreel film, gave the gas a bad name, though it was subsequently shown that hydrogen was unlikely to have been the primary cause of this. However, it was still used in the barrage balloons that were to me an interesting feature of the skies over Liverpool during the Second World War.
So, by the mid-20th century, hydrogen was being produced commercially from steam and had been shown to have potential to transport people. Moreover, by then many other discoveries had been made that have now led to renewed interest in it as an important agent in escaping from the grip of climate change.
The first of these discoveries, in 1800, was that water could be decomposed by electricity, the process of electrolysis. Next, in 1840, William Grove showed that it was possible to generate electricity from the energy generated by chemical reactions, combining oxygen and hydrogen in a battery with electrodes of different metals. This was later named a fuel cell, the industrial application of which started in the 1920s. After development by NASA, for providing energy in its rockets, it has now found many applications, especially for producing power in remote locations. Fuel cells require a fuel, and hydrogen is commonly used for this purpose since it is light, efficient and causes no pollution.
The central problem we face today is to stop using fossil fuel for generating the energy we need. Looking back 250 years, almost all our energy came from burning wood and charcoal, from the force of rivers to drive machines, from the wind to move boats and drive windmills, and from animal and human labour. Can we go back to those primary sources: the power of water and wind? At least an important part of the answer lies in our ingenuity in aiming for this. The future of these islands depends on it and Scotland has a critical part to play, though our dependence on oil has unfortunately held us back from seizing the initiative.
As long ago as 1923, JBS Haldane in a lecture entitled Daedalus; or, Science and the Future
As for the supplies of mechanical power, it is axiomatic that the exhaustion of our coal and oil-fields is a matter of centuries only. As it has often been assumed that their exhaustion would lead to the collapse of industrial civilisation, I may perhaps be pardoned if I give some of the reasons which lead me to doubt this proposition.
Water-power is not, I think, a probable substitute, on account of its small quantity, seasonal fluctuation, and sporadic distribution... Ultimately, we shall have to tap those intermittent but inexhaustible sources of power, the wind and the sunlight. The problem is simply one of storing their energy in a form as convenient as coal or petrol. If a windmill in one's back garden could produce a hundredweight of coal daily (and it can produce its equivalent in energy), our coalmines would be shut down tomorrow. Even tomorrow a cheap, foolproof, and durable storage battery may be invented, which will enable us to transform the intermittent energy of the wind into continuous electric power.
Personally, I think that 400 years hence the power question in England may be solved somewhat as follows: The country will be covered with rows of metallic windmills working electric motors which in their turn supply current at a very high voltage to great electric mains. At suitable distances, there will be great power stations where during windy weather the surplus power will be used for the electrolytic decomposition of water into oxygen and hydrogen. These gasses will be liquefied, and stored in vast vacuum jacketed reservoirs, probably sunk in the ground...
In times of calm, the gasses will be recombined in explosion motors working dynamos which produce electrical energy once more, or more probably in oxidation cells. Liquid hydrogen is weight for weight the most efficient known method of storing energy, as it gives about three times as much heat per pound as petrol. On the other hand, it is very light, and bulk for bulk has only one third of the efficiency of petrol. This will not, however, detract from its use in aeroplanes, where weight is more important than bulk. These huge reservoirs of liquified gasses will enable wind energy to be stored, so that it can be expended for industry, transportation, heating and lighting, as desired.
The initial costs will be very considerable, but the running expenses less than those of our present system. Among its more obvious advantages will be the fact that energy will be as cheap in one part of the country as another, so that industry will be greatly decentralised; and that no smoke or ash will be produced.
In a previous essay (1 September
), I mentioned the action of the Danish Oil and Natural Gas Company that moved to production of windfarms and re-named itself after Hans Christian Ørsted, the scientist who first showed that passing an electric current through a wire generated a magnetic field. That company is now, less than 100 years after Haldane's lecture, proposing to do exactly what he foretold, producing hydrogen by wind-powered electrolysis of water. As we have all observed, wind turbines are now widely dispersed both on- and off-shore in the UK. In 2020, over 97% of electricity consumed in Scotland was renewable, 71% wind, 18% hydro and 8% from solar and other sources.
Currently, hydrogen is produced commercially from natural gas and methane, but this process produces CO2 which then needs to be captured and disposed of for the process to be carbon neutral. A further problem that will have occurred to you is the lack of water itself in many parts of the world and that climate change is exacerbating this. Only 1% of the Earth's water is on land, so the obvious answer is to use seawater. However, pure water is necessary to produce hydrogen as the salts in seawater interfere with the electrodes used in electrolysis. Various laboratory-scale solutions are available, such as chlorine-resistant electrodes, nanoparticle catalysts, and the use of reverse osmosis to desalinate the water; it is likely that some of these can be scaled up for industrial purposes.
It is now necessary to move away from natural gas and oil for domestic heating, and from petrol and diesel for our vehicles. It looks as though hydrogen will play an important part in this transition. Trials already underway are substituting it for natural gas in adapted domestic heating boilers, and hydrogen fuel cells have been used to power vehicles and even aeroplanes.
Solutions to the energy problem are available and the production, distribution and storage technologies are advancing rapidly but require investment. This calls for a change in mindset of the world's governments away from fixation on fossil fuels. We in the UK are fortunate to have plenty of wind and water and are in a position to set an example, but action must be worldwide if we are to slow climate change. Time is short. Daily news of wildfires, drought, and hurricanes serves to remind us of this.
JBS Haldane was born in Oxford but had Scottish blood on both sides. His father, J Scott Haldane, was born in Edinburgh in 1860, a son of the Enlightenment who was famed for his studies of gases. He invented an apparatus which was still used for measuring CO2 in breath in my lung function laboratory in the 1970s.
The lecture quoted above made me realise very acutely how we in Britain have not only squandered our oil and gas reserves (unlike Norway) but also how we have failed to respond politically over the past 30 years to the known challenge from climate change by investing some of the proceeds into developing alternatives. We do have the scientific and technological expertise, but our leaders have failed to take the long-term view and have chosen to look for short-term political opportunities rather than to plan for the increasingly obvious future problems. The twin disasters of Brexit and our response to the pandemic exemplify this. We have, as citizens, been complicit by trusting in their proposals and voting for them.
I hope it is not now too late for us to change our own lives and encourage every political party to put planning for climate change at the centre of all policy.
Anthony Seaton is Emeritus Professor of Environmental and Occupational Medicine at Aberdeen University and Senior Consultant to the Edinburgh Institute of Occupational Medicine. The views expressed are his own