Electric motors: state of flux?

Motor innovations are an overlooked enabler for the electrification of transport. This 15-page note explores whether axial flux motors could come to dominate in the future. They promise 2-3x higher power densities, even versus Tesla’s world-leading PMSRMs; and 10-15x higher than clunky industrial AC induction units; while also surpassing c96% efficiencies. This extends the range of EVs and the promise of drones/aerial vehicles.


Traditional AC induction motors are described on pages 2-6, outlining how they work, their efficiency, middling reliability and typically low power density.

Electrification of transport already uses a step-change in motor design, to yield higher power density and controllability. Tesla’s PMSRM is world-leading. Details are laid out on page 7.

But a totally novel motor design is gaining ground. This is the axial flux motor, described on pages 8-11. Power density is 10x a traditional AC induction machine, efficiency is enhanced, and lower material usage may also yield important cost-savings.

Power electronics are overlooked in the revolution of electrifying transport. We note the importance of Moore’s Law on page 12, in the attempt to electrify passenger cars, two-wheelers and even aerial vehicles in the future.

Leading companies in axial flux motors are profiled on pages 13-15, based on reviewing 1,200 patents, and the technical specifications of their products. Auto-makers have started acquiring industry leaders, while earlier-stage companies are also raising capital.

Drones & droids: deliver us from e-commerce

Small, autonomous, electric delivery vehicles are emerging. They are game-changers: rapidly delivering online purchases to customers, creating vast new economic possibilities, but also driving the energy transition. Their ascent could eliminate 500MTpa of CO2, 3.5Mboed of fossil fuels and c$3trn pa of consumer spending across the OECD. The mechanism is a re-shaping of urban consumption habits, retail and manufacturing. The opportunities are outlined in our new, 20-page report.


The average US consumer buys 2.5 tons of goods per year, served by a vast distribution network of ships, trucks and smaller vehicles, collectively responsible for 1.5 barrels of oil, $1,000 of cost and 600kg of CO2 per person per annum (page 2).

Fuel economy currently deteriorates, with each step closer to the consumer. Container ships achieve c900 ton-miles per gallon of fuel. But delivery vans, the dominant delivery mechanism for internet purchases, are least efficient, achieving just 0.02 effective ton-mpg and costing at least $3.6 per delivery (page 3).

The rise of e-commerce has already increased supply chain CO2 by c30%, and supply chain costs by 2x since the pre-internet era. On today’s technologies, CO2 will rise another 20% and cost will rise another 50% by 2030, adding 0.7Mbpd of oil demand, 120MTpa of CO2 and $500bn of cost across the OECD (pages 4-5)

Drones and droids are 90-99% less energy intensive than delivery vans, and 70-97% less costly. The technology is maturing. Thus small, autonomous, electric vehicles will move immediately, efficiently, straight to their destination (pages 6-8).

Retail and manufacturing will have be transformed by the time drones approach 50% market share in last-mile delivery. Tipping-point economies-of-scale mean that they will take market share away from cars and delivery vans very rapidly (pages 9-10).

The second half of the report focuses in on the opportunities. Retail businesses must consolidate, specialise or diversify to “sharing” models. The latter can save $1trn of consumer spending and 100MTpa of emissions in the US alone (pages 11-20).

Copyright: Thunder Said Energy, 2022.