Michael Kelly: The green energy Net Zero plan will require a command economy

By Paul Homewood

 

 

Imagine the USA in 2050 has a net-zero emissions economy, as President Joe Biden has pledged that it will (the UK is also committed to this).

Three very large, interrelated, and multidisciplinary engineering projects will need to have been completed. Transport will have been electrified. Industrial and domestic heat will have been electrified. The electricity sector – generation, transmission and distribution – will have been greatly expanded in order to cope with the first two projects, and will have ceased to use fossil fuels.
I have had a long career in industrial and academic engineering, and recently retired as Professor of Technology in electrical engineering at Cambridge University. I’ve spent some time looking into the feasibility of these ideas, and these are the facts.

At the moment the USA uses on average 7,768 trillion British Thermal Units of energy every month, most of which is supplied by burning fossil fuel either directly for heat or transport, or indirectly to generate electricity.
Because an internal combustion engine converts the energy stored in its fuel into transport motion with an efficiency of about 30 per cent, while electric motors are more than 90 per cent efficient at using energy stored in a battery, we will need to increase the US electricity supply by about 25 per cent to maintain transport in the USA at today’s level. Let’s assume that replacing today’s fossil-powered vehicles and trains with electric ones will cost no more than we would have spent replacing them anyway: it’s not really true but the difference is small compared to the rest of this. I should note however that a small part of today’s transport energy is used for aviation and shipping, which are much harder to electrify than ground transport, but we’ll ignore that for now.

Next we need to electrify all the heat. If this heat was provided by ordinary electric heaters, we would need an extra electrical sector equal to the size of today’s. But if we mostly use air-source and ground-source heat pumps, and assume a coefficient of performance of 3:1 – optimistic, but not wildly unreasonable – then we only need new grid capacity equivalent to 35 per cent of the size of the present grid for the heat task.

So far, the grid in 2050 will need to be more than 60 per cent bigger than its present size. We also need to work on the buildings. US building stock is made up of nearly 150 million housing units, commercial and industrial buildings, with an estimated floor space of 367 billion square feet. Some of this is well insulated, much of it is not. All of it would need to be, for our heat pumps to work at the efficiencies we need them to. Based on a UK pilot retrofit programme the national scale cost for this is $1 trillion per 15 million population. The figure in the USA could therefore be about $20 trillion. It might be as high as $35 trillion.

We should note here that as with transport, some specialist types of heating cannot at the moment be done electrically, for instance in primary steel production. These will involve extra costs if net zero is to be reached, but we’ll ignore that for now, even though we’re going to need an awful lot of steel.
Now let’s get the power grid decarbonised and make it 60 per cent bigger and more powerful. Taken together, the US electrical grid has been called the largest machine in the world: 200,000 miles of high-voltage transmission lines and 5.5 million miles of local distribution ones. We will need to add a further 120,000 miles of transmission line. This will cost on the order of $0.6 trillion, based on US cost data.

The 5.5 million miles of local distribution lines will have to be upgraded to carry much higher currents. Most houses in the USA have a main circuit-breaker panel that allows between 100 and 200 amps (A) current into the house, although some new ones are rated at 300A. The 100A standard was set nearly a century ago, when the electric kettle was the largest single appliance. In a modern all-electric home, some of the new appliances draw rather higher currents: ground-source heat pumps may draw 85A on start-up, radiant hobs when starting up draw 37A, fast chargers for electric vehicles draw 46A, and even slow ones may draw 17A, while electric showers draw 46A. The local wiring in streets and local transformers were all sized to the 100-A limit. Most homes will need an upgraded circuit breaker panel and at least some rewiring, and much local wiring and many local substations will need upsizing. The UK costs have been estimated in detail at £1 trillion, which would scale to the order of $6 trillion on a per-capita basis.

As 60 per cent of the current electrical generation is fossil fuelled, we need to close all the fossil stations down and increase the remaining, non-fossil generation capacity four times over. There isn’t much scope for new hydropower, and so far carbon capture doesn’t exist outside fossil fuel production. Using a mixture of wind (onshore $1600/kW, offshore $6500/kW), solar ($1000/kW at the utility level) and nuclear ($6000/kW), the capital cost of this task alone is around $5 trillion, and we have not dealt with the enormous problem of wind and solar being intermittent.
So far we’re up to $32 trillion as the cost of providing the insulated buildings and the generation, transmission and distribution of electricity in a net-zero world. Although not all borne by households, this figure is of the order of $260,000 per US household.

Now let’s think about intermittency. Sometimes there is no wind and no sunshine, and our largely renewables-driven grid will have no power. Current hydropower storage would run a net-zero grid in the USA for a few hours; current battery capacity could do so for a few minutes. Net-zero advocates often suggest simply building huge amounts of battery storage, but the costs of this are colossal: 80 times as much as the power plants, hundreds of trillions of dollars. And indeed this is simply fantasy as the necessary minerals are not available in anything like the required amounts. If prices climbed, more reserves would become economic – but the prices are already impossibly high.

Straight away, we can see that a net-zero grid with a large proportion of renewables simply cannot be built. But for now let’s just ignore the storage problem and look at some more numbers.
The UK engineering firm Atkins estimates that a $1-billion project in the electrical sector over 30 years needs 24 or more professional, graduate engineers and 100 or more skilled tradespeople for the whole period. Scaling up these figures for the $12 trillion of electricity sector projects just described, we will need 300,000 professional electrical engineers and 1.2 million skilled tradespeople, full time, for the 30 years to 2050 on just this part of the net-zero project. Based on the budget, we might expect the buildings retrofit sector to need a similar workforce of roughly three million people. This is a combined workforce roughly the size of the entire existing construction sector.

Now let’s think about materials. A 600-megawatt (MW) combined-cycle gas turbine (CCGT) needs 300 tonnes of high-performance steels. We would need 360 5-MW wind turbines, each running at an optimistic average 33 per cent efficiency (and a major energy storage facility alongside which we are just ignoring as it would be impossibly expensive) to achieve the same continuous 600-MW supply. In fact, since the life of wind turbines at 25 years is less than half that of CCGT turbines, we would actually need more than 720 of them.
The mass of the nacelle (the turbine at the top of the tower) for a 5-MW wind turbine is comparable to that of a CCGT. Furthermore, the mass of concrete in the plinth of a single CCGT is comparable to the mass of concrete for the foundations of each individual onshore wind turbine, and much smaller than the concrete and ballast for each offshore one. We are going to need enormous amounts of high-energy materials such as steel and concrete: something like a thousand times as much as we need to build CCGT or nuclear powerplants, and renewed more frequently. This vast requirement is probably going to affect prices, both of materials and energy – and not in a good way – but for now we’ll just assume costs remain at something like current levels.

So we can see that the infrastructure parts of the net-zero project which are theoretically possible would cost comfortably in excess of $35 trillion and would require a dedicated and highly skilled workforce comparable to that of the construction sector as well as enormous amounts of materials. Net zero would also require several things which today are completely impossible: scalable non-fossil energy storage, very high temperature electrical industrial processes, serious electrical aviation and shipping. There would also be the matter of decarbonising agriculture. These things, if they can even be achieved, would multiply the cost at least several times over, to more than $100 trillion.

So the real cost of net-zero, or more likely of trying and failing to achieve it, would be similar to – or even more than – total projected US government spending out to 2050. There is no likelihood of that amount of money being diverted from other purposes under anything resembling normal market economics and standards of living.
The idea that net zero can be achieved on the current timelines by any means short of a command economy combined with a drastic decline in standards of living – and several unlikely technological miracles – is a blatant falsehood. The silence of the National Academies and the professional science and engineering bodies about these big picture engineering realities is despicable.
People need to know the realities of net zero.

Michael Kelly is Emeritus Professor of Engineering at the University of Cambridge. He is a Fellow of the Royal Society, of the Royal Academy of Engineering, of the Royal Society of New Zealand, of the Institute of Physics and of the Institution of Engineering and Technology, as well as Senior Member of the Institute of Electronic and Electrical Engineering in the USA. He is a trustees of the Global Warming Policy Foundation.