Thoughts on Arianrhod



I was (re-)watching the 1992 film Hedd Wyn recently. It tells the story of the Welsh poet Ellis Evans, the poet of the Black Chair, who was killed during the battle of Passchendaele in 1917.

There’s a scene in which Evans is standing outside the family farmhouse on a cold winter’s night, mentally composing the poem which will win him second place in that year’s National Eisteddfod. His sister comes out, wrapped in a blanket, to demand why he’s standing out there on his own. Evans, who has been gazing at the full moon, replies “I’m not on my own. She’s with me. Arianrhod. The ancient name for the moon”.

The moon… and inspiration… and much more. As I wrote in a previous post, Arianrhod is the goddess of poetry, and culture, and of social memory. She is the goddess of rite and ritual, and of transition through…

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Natural History Museum letter to UK statutory Committee on Climate Change – June 2019 – copy

3rd June 2019

Committee on Climate Change

7 Holbein Place,



Dear Committee Members,

Re: Reaching net zero emissions in the UK by 2050

In the Committee on Climate Change’s May 2019 report1 the key conclusion is ‘that net-zero is necessary, feasible and cost-effective’. The report is laudable but we attest is only likely to be feasible if considerations are made on the resource implication of what is needed to achieve that goal.

A key component of the net zero attainment is for ‘all cars and vans to be electric by 2050’.  This further requires ‘all sales to be pure battery electric by 2035 at the latest’.  In the report the need for vehicle charging facilities and infrastructure to support this change are acknowledged, but it entirely omits the challenge of the metal resources needed to produce the vehicles that will lead to this revolution. 

There are currently 31.5 million cars on the UK roads. Between them they cover 252.5 billion miles per year2. In 2017 electric and hybrid cars accounted for about 0.2% of the UK fleet, so that clearly needs to change rapidly for this to reach 100% by 2050.  The stated challenge for all sales to be pure battery by 2035 is also a steep ask, given projections for vehicle sales, set to be around 2.5 million new vehicles per year.

Electric vehicles are resource hungry.  Although the body and chassis are largely constructed from the same materials as internal combustion engine vehicles, the drive train and fuel (comprising stored electricity in the form of batteries) demand a new range of metals.  An average battery electric vehicle with the next generation, low cobalt, NMC811 battery, will demand 6.6 kg cobalt and 8.4 kg of LCE (lithium carbonate equivalent)3.  In addition, the electric drive chain contains between 1-2 kg of neo-magnets, containing around 0.2kg neodymium and 0.03kg dysprosium.  Electric vehicles also need, on average, 90kg of copper for wiring to connect the battery and drive train.  It should be noted that a conventional car currently contains between 9 and 25 kg copper along with minor cobalt in structural steel elements and minor rare earths for the electrical systems.

To replace all these UK-based vehicles today with electric vehicles (not including the LGV and HGV fleets), assuming they use the most resource-frugal next-generation NMC 811 batteries, it would take 207,900 tonnes cobalt,  264,600 tonnes of lithium carbonate (LCE), at least 7,200 tonnes of neodymium and dysprosium, in addition to 2,362,500 tonnes copper.  This represents, just under two times the total annual world cobalt production, nearly the entire world production of neodymium, three quarters the world’s lithium production and at least half of the world’s copper production during 2018. Even ensuring the annual supply of electric vehicles only, from 2035 as pledged, will require the UK to annually import the equivalent of the entire annual cobalt needs of European industry.

If we are to extrapolate this analysis to the currently projected estimate of 2 billion cars worldwide1, based on 2018 figures, annual production would have to increase for neodymium and dysprosium by 70%, copper output would need to more than double and cobalt output would need to increase at least three and a half times for the entire period from now until 2050 to satisfy the demand.

This choice of vehicle comes with an energy cost too.  Energy costs for cobalt production are estimated at 7000-8000 kWh for every tonne of metal produced4 and for copper 9000 kWh/t5.  The rare earth energy costs are at least 3350 kWh/t6, so for the target of all 31.5 million cars that requires 22.5 TWh of power to produce the new metals for the UK fleet, amounting to 6% of the UK’s current annual electrical usage7.  Extrapolated to 2 billion cars worldwide, the energy demand for extracting and processing the metals is almost 4 times the total annual UK electrical output.

Furthermore there are serious implications for the electrical power generation in the UK needed to recharge these vehicles. Using figures published for current EVs (Nissan Leaf, Renault Zoe), driving 252.5 billion miles uses at least 63 TWh of power. This will demand a 20% increase in UK generated electricity.  If wind turbines are chosen for this extra capacity, each GW of added power capacity for new generation wind turbines uses 4700t copper, 200t neodymium and 13t dysprosium8. Data shows that wind farms in the UK operate at about 40% of their nominal capacity9, so for the 63 TWh needed annually to fuel the EV fleet, 18GW of new installed capacity is needed.  Equating to 6000 wind turbines of 3MW capacity, these demand an additional 84,600t of copper, 3600t of neodymium and 234t of dysprosium.  If we are to power all of the projected 2 billion cars at UK average usage, this requires the equivalent of a further years’ worth of total global copper supply and 10 years’ worth of global neodymium and dysprosium production to build the windfarms. The solar alternative to wind is also resource hungry; all the photovoltaic systems currently on the market are reliant on one or more raw materials classed as “critical” or “near critical” by the EU and/ or US Department of Energy 10 (high purity silicon, indium, tellurium, gallium) because of their natural scarcity or their recovery as minor-by-products of other commodities. With a capacity factor of only ~10%11, the UK would require ~72GW of photovoltaic input to fuel the EV fleet; over five times the current installed capacity. If CdTe-type photovoltaic power is used, that would consume over thirty years of current annual tellurium supply.  Both these wind turbine and solar generation options for the added electrical power generation capacity have substantial demands for steel, aluminium, cement and glass which has been highlighted by previous authors12

It is clear that our move to a lower-CO2 society and industry has a significant resource footprint, such that the availability (and price) of raw materials will likely be a major limiting factor. The UK’s industrial  and environmental strategies will depend not just on novel technologies for energy generation, but on the discovery of new mineral resources, and more efficient extraction of a greater diversity and amount of elements and minerals from our mines.  This has to be achieved while reducing the environmental impacts and energy consumption of those extractive industries. Researchers in the UK are engaged in research to do just this – the recent “Security of Supply” programme funded jointly by NERC, EPSRC, Newton and FAPESP ( focussed on improving our understanding of how particular scarce elements become concentrated in particular ore deposits, and how we can better extract them. Across the programme, our research has identified potential sources for cobalt, rare earths, tellurium and more; modelled the impacts of mining seabed resources; calculated the environmental and energy footprints of competing REE resources; piloted cobalt extraction through novel bio-processing; and developed new “deep eutectic” solvents capable of recovering a suite of metals with low energy inputs and water consumption.

This research represents the tip of the iceberg. Over the next few decades, global supply of raw materials must drastically change to accommodate not just the UK’s transformation to a low carbon economy, but the whole world’s. It is essential to have timely and sustainable supplies of raw materials in quantities greatly exceeding current global mining and processing capacity. There is space for us to look again at the our own local mineral endowment; Europe has great potential for many of these commodities but the current economics, socio-political framework and export of mining from the developed world have led the world’s mining industry to seek minerals in more permissive tracts, a move that has itself led to risks in the supply chain13.  The UK itself has potential for some of the metals needed for these new vehicles, but currently we do not have a a clear measure of that local potential.  Society needs to understand that there is a raw material cost of going green and that both new research and investment is urgently needed for us to evaluate new ways to source these, potentially considering sources much closer to where the metals are to be used. 

We would welcome the opportunity to discuss the contents of our letter with the committee and work with interested parties to build on the useful research started through the SoS MinErals programme and seek solutions for the resource supply challenge that a ‘Net Zero’ pledge raises.

Yours sincerely,

Professor Richard Herrington, Head of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD Email: (corresponding author)

Professor Adrian Boyce, Professor of Applied Geology at The Scottish Universities Environmental Research Centre

Paul Lusty, Team Leader for Ore Deposits and Commodities at British Geological Survey

Dr Bramley Murton, Associate Head of Marine Geosciences at the National Oceanography Centre

Dr Jonathan Naden, Science Coordination Team Lead of NERC SoS MinErals Programme, British Geological Society

Professor Stephen Roberts, Professor of Geology, School of Ocean and Earth Science, University of Southampton

Associate Professor Dan Smith, Applied and Environmental Geology, University of Leicester

Professor Frances Wall, Professor of Applied Mineralogy at Camborne School of Mines, University of Exeter


  1. Net Zero – The UK’s contribution to stopping global warming, 2019, report, UK Parliamentary Committee on Climate Change, London, May 2019, 275pp
  2. RAC Foundation
  3. McKinsey & Co Metals and Mining June 2018 Report
  4. Dai et al. 2018
  5. Energy Use in Copper Production, Rankin 2012
  6. Piero and Mendez (2013) 10.1007/s11837-013-0719-8
  7. Energy consumption in the UK, 2015, UK Department of Energy & Climate Change
  8. Ayman Elshkaki and T.E. Graedel, 2014, Dysprosium, the balance problem, and wind power technology, Applied Energy, 136, 548-559
  9. Energy Numbers Info
  10. Hayes & McCullough, Critical minerals: A review of elemental trends in comprehensive criticality studies, Resources Policy, V. 59, 2018
  11. Hemingway, James (2013). “Estimating generation from Feed in Tariff installations” (pdf). Energy Trends. Department of Energy & Climate Change.
  12. Vidal et al. (2013)
  13. Herrington (2013)