Michael Kelly was the inaugural Prince Philip Professor of Technology at the University of Cambridge. His interest in the topic of this lecture was roused during 2006–9 when he was a part time Chief Scientific Adviser to the Department for Communities and Local Government. On his return full-time to Cambridge he was asked by his engineering colleagues to lead the teaching of final-year and graduate engineers on present and future energy systems, which he did until he retired in 2016. Michael Kelly recently spoke on the topic Energy Utopias and Engineering Reality. The text of his remarks is published by GWPF. This post provides a synopsis consisting of excerpts in italics with associated images and my bolds.
Just so that there can be no doubt whatsoever, the real-world data shows me that the climate is changing, as indeed it has always changed. It would appear by correlation that mankind’s activity, by way of greenhouse gas emissions, is now a significant contributory factor to that change, but the precise percentage quantification of that factor is far from certain. The global climate models seem to show heating at least twice as fast as the observed data over the last three decades. I am unconvinced that climate change represents a proximate catastrophe, and I suggest that a mega-volcano in Iceland that takes out European airspace for six months would eclipse the climate concerns in short order.
The detailed science is not my concern here. The arguments in this lecture would still apply if the actual warming were twice as fast as model predictions.
Project engineering has rules of procedure and performance that cannot be circumvented, no matter how much one would wish it. Much of what is proposed by way of climate change mitigation is simply pie-in-the-sky, and I am particularly pleased to have so many parliamentarians here tonight, as I make the case for engineering reality to underpin the public debate.
I plan to describe:
(i) the global energy sector,
(ii) the current drivers of energy demand,
(iii) progress to date on decarbonisation, and the treble challenges represented by
(iv)factors of thousands in the figures of merit between various forms of energy,
(v) the energy return on energy invested for various energy sources, and
(vi) the energising of future megacities.
I make some miscellaneous points and then sum up. The main message is that our present energy infrastructure is vast and has evolved over 200 years. So the chances of revolutionising it in short order on the scale envisaged by the net-zero target of Parliament is pretty close to zero; zero being exactly the chance of the meeting Extinction Rebellion’s demands.
The energy sector – its scale and pervasiveness
As society evolves and civilisation advances, energy demands increase. As well as increasing
demand for energy, the Industrial Revolution led to an increase in global population, which had been rather static until about 1700. Since then, both the number of people and the energy consumption per person have increased, and from Figure 2 we can see the steady growth of gross domestic product per person and energy consumption through the 19th and 20th centuries until now.
Energy is the essential driver of modern civilisation. World GDP this year is estimated at $88 trillion, growing to $108 trillion by 2023, with the energy sector then being of order $10 trillion. But renewables have played, and will continue to play, a peripheral role in this growth. Industrialisation was accompanied by a steady and almost complete reduction in the use of renewables (Figure 4).
In recent years, there has been an uptick in renewables use, but this has been entirely the result of the pressure to decarbonise the global economy in the context of mitigating climate change, and the impact has again been nugatory. Modern renewables remain an insignificant share of the energy supply. Indeed MIT analysts suggest the transition away from fossil fuel energies will take 400 years at the current rate of progress.
Figure 6 shows the scale of what has been proposed. Even reaching the old target of an
80% reduction in carbon dioxide emissions would be miraculous; this is a level of emissions
not seen since 1880. I assert that a herd of unicorns will be needed to deliver this target,
let alone full decarbonisation. I also point out the utter nonsense of Extinction Rebellion’s
demands to complete the task by 2025.
Contemporary drivers of energy needs 1995–2035
I wish to focus on the drivers of global energy demands today by looking back and forward
twenty years. Figure 7 shows data from BP covering the period 1965–2035 on the demand
for global energy by fuel type. The data to 2015 is historic and not for challenge.
One notes that we have not had an ‘energy transition’: fossil fuels have continued to grow steadily at a rate about 7–8 times that of renewable technologies over the last 20 years. The energy demand of the major developed countries has been static or in small decline over that period. Most of the increase has come from growth in the global middle class, which increased by 1.5 billion people in the 20 years to 2015.
The whole of Figure 7 can be explained quantitatively if one assumes that a middle class person (living in a high rise building with running water and electricity, without any mention of personal mobility – the World Bank definition of middle class existence – uses between three and four times the amount of energy per day as a poor person in a rural hovel or urban slum.
You should be under no illusions: this is a humanitarian triumph. It is the delivery of the top Sustainable Development Goals – the elimination of poverty and hunger – that has been and will remain the main driver of energy demand for the foreseeable future.
Decarbonisation progress to date
In the UK, the Climate Change Committee has, on the face of it, overseen a steady fall in UK emissions of carbon dioxide since its formation in 2008. However, the fall started in 1990 and has continued at a very steady rate since (Figure 8a).
However, UK decreases are dwarfed by global increases. After no-growth years in 2016 and 2017, global carbon dioxide emissions grew by 3% in 2018 (Figure 8b). European emissions fell but the growth in all the other parts of the world was 17 times greater. The emissions reductions in the UK have also come at a considerable cost. The deficit of the UK balance of payments with respect to manufactures has been increasing since then. In other words, a significant proportion of our emissions have been exported to China and elsewhere. Indeed, over the period 1991– 2007, the emissions associated with rising imports almost exactly cancelled the UK emissions reduction!
There was much publicity in late summer this year when 50% of the UK’s electricity was (briefly) generated from renewables. Few people realised that electricity is only 16% of our total energy usage, and it is a common error, even in Parliament, to think that we are making enormous progress on the whole energy front. The real challenge is shown in Figure 10, where the energy used in fuels, heating and electricity are directly compared over a three year period. Several striking points emerge from this one figure.
First, we use twice as much energy in the UK for transport as we do for electricity. Little progress has been made in converting the fuel energy to electricity, as there are few electric vehicles and no ships or aircraft that are battery powered.
Note that if such a conversion of transport fuel to electricity were to take place, the grid capacity would have to treble from what we have today.
Second, most of the electricity use today is baseload, with small daily and seasonal variations (one can see the effect of the Christmas holidays). The more intermittent wind and solar energy is used, the more back-up has to be ready for nights and times of anticyclones or both: the back-up capacity could have been used all along to produce higher levels of baseload electricity, and because it is being used less efficiently, the resulting back-up generation costs more as it pays off the same total capital costs.
But in fact it is the heating that is the real problem. Today that is provided by gas, with gas flows varying by a factor of eight between highs in winter and lows in summer. If heat were to be electrified along with transport, the grid capacity would have to be expanded by a factor between five and six from today. How many more wind and solar farms would we need?
So far, I have described the scale of the global energy sector, how it has come to be the size it is, the current drivers for more energy and the current status of attempts to decarbonise the global economy. I can draw some initial conclusions at this point.
• Energy equals quality of life and we intervene there only with the most convincing of
• Renewables do not come close to constituting a solution to the climate change problem for an industrialised world.
• China is not the beacon of hope it is portrayed to be.
• There is no ground shift in energy sources despite claims to contrary.
The engineering challenges implied by factors of hundreds and thousands
Many people do not realise the very different natures of the forms of energy we use today. But energy generation technologies can differ by factors of hundreds or thousands on key measures, such as the efficiency of materials use, the land area needed, the whole-life costs of ownership, and matters associated with energy storage.
Here are four statements about the efficiency with which energy generation systems use
high-value advanced materials:
• A Siemens gas turbine weighs 312 tonnes and delivers 600 MW. That translates to 1920 W/kg of firm power over a 40-year design life.
• The Finnish PWR reactors weigh 500 tonnes and produces 860 MW of power, equivalent to 1700 W/kg of firm supply over 40 years. When combined with a steam turbine, the figure is 1000 W/kg.
• A 1.8-MW wind turbine weighs 164 tonnes, made up of a 56-tonne nacelle, 36 tonnes
for the blades, and a 71-tonne tower. That is equivalent to 10 W/kg for the nameplate
capacity, but at a typical load factor of 30%, this corresponds to 3 W/kg of firm power.
A 3.6-MW offshore turbine, with its 400-tonne above-water assembly, and with a 40%
load factor, comes out at 3.6 W/kg over a 20-year life.
• Solar panels for roof-top installation weigh about 16 kg/m2, and with about 40 W/m2
firm power provided over a year, that translates to about 2.5 W/kg energy per mass
over a 20-year life.
The figures are shown in Figure 12, although the wind and solar bars are all but invisible.
You’d need 360 5-MW wind turbines (of 33% efficiency) to produce the same output as a gas turbine, each with concrete foundations of comparable volume.
The late David MacKay showed that the land areas needed to produce 225 MW of power were very different: 15 acres for a small modular nuclear reactor, 2400 acres for average solar cell arrays, and 60,000 acres for an average wind farm.
Approximate area required for all of
London’s electricity to come from wind farms
The challenge of megacities
In 2050 over half the world’s population will be living in megacities with populations of more
than 5 million people. The energising of such cities at present is achieved with fossil and
nuclear fuels, as can the cities of the future. The impact of renewable energies will be very
small, as the vast areas of land needed, often taken away from local areas devoted to food
production as in London or Beijing, will limit their contribution. The extreme examples are
Hong Kong and Singapore, neither of which have any available hinterland.
It is clear to me that, for the sake of the whole of mankind, we must stay with business as usual, which has always had a focus on the efficient use of energy and materials. Climate change mitigation projects are inappropriate while large-scale increases in energy demand continue. If renewables prove insufficiently productive, research should be diverted to focus on genuinely new technologies. It is notable that within a few decades of Watt’s steam engine becoming available, the windmills of Europe ceased turning. We should not be reversing that process if the relative efficiencies have not changed. We must de-risk major infrastructure projects, such as mass decarbonisation. They are too serious to get wrong. Human lifestyle changes can have a greater and quicker impact:they could deliver a 10% drop in our energy consumption from tomorrow. This approach would not be without consequences, however. For example, airlines might well collapse if holidaymakers stayed, or were made to stay, at home.
Who owns the integrity of engineering in the climate debate in the United Kingdom? Globally? The Royal Society, the Royal Academy of Engineering and the Engineering Institutions should all be holding the fort for engineering integrity, and not letting the engineering myths of a Swedish teenager go unchallenged.
Footnote: See also a previous 2015 article by Kelly in Standpoint Magazine: For Climate Alarmism, The Poor Pay The Price Some excerpts in italics with my bolds.
During a period as a scientific adviser in Whitehall, I quickly learned the elements of sound advice given to politicians — a process that is quite distinct from lobbying. A well-briefed minister knows about the general area in which a decision is sought, and is given four scenarios before any recommendation. Those scenarios are the upsides and the downsides both of doing nothing and of doing something. Those who give only the upside of doing something and the downside of doing nothing are in fact lobbying.
In his introduction he (Stern) makes it clear that he has consulted many scientists, businessmen, philosophers and economists, but in his book I find not a single infrastructure project engineer asked about the engineering reality of any of his propositions, nor a historian of technology about the elementary fact that technological breakthroughs are not pre-programmable. Lord Stern’s description of the climate science is an uncritical acceptance of the worst case put by the International Panel on Climate Change (IPCC), one from which many in the climate science community are now distancing themselves.
Those building the biblical Tower of Babel, intending to reach heaven, did not know where heaven was and hence when the project would be finished, or at what cost. Those setting out to solve the climate change problem now are in the same position. If we were to spend 10 or even 100 trillion dollars mitigating carbon dioxide emissions, what would happen to the climate? If we can’t evaluate whether reversing climate change would be value for money, why should we bother, when we can clearly identify many and better investments for such huge resources?
The Paris meeting on climate change will be setting out to build a modern Tower of Babel.