US Crosses the Electric-Car Tipping Point for Mass Adoption


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EV Tipping Point signals the S-curve shift to mainstream adoption as new car sales pass 5%, with the US joining Europe and China; charging infrastructure, costs, and supply align to accelerate electric car market penetration.

 

Key Points

The EV tipping point is when fully electric cars reach about 5% of new sales, triggering rapid S-curve adoption.

✅ 5% of new car sales marks start of mass adoption

✅ Follows S-curve seen in phones, LEDs, internet

✅ Barriers ease: charging, cost declines, model availability

 

Many people of a certain age can recall the first time they held a smartphone. The devices were weird and expensive and novel enough to draw a crowd at parties. Then, less than a decade later, it became unusual not to own one.

That same society-altering shift is happening now with electric vehicles, according to a Bloomberg analysis of adoption rates around the world. The US is the latest country to pass what’s become a critical EV tipping point: an EV inflection point when 5% of new car sales are powered only by electricity. This threshold signals the start of mass EV adoption, the period when technological preferences rapidly flip, according to the analysis.

For the past six months, the US joined Europe and China — collectively the three largest car markets — in moving beyond the 5% tipping point, as recent U.S. EV sales indicate. If the US follows the trend established by 18 countries that came before it, a quarter of new car sales could be electric by the end of 2025. That would be a year or two ahead of most major forecasts.

How Fast Is the Switch to Electric Cars?
19 countries have reached the 5% tipping point, and an earlier-than-expected shift is underway—then everything changes

Why is 5% so important? 
Most successful new technologies — electricity, televisions, mobile phones, the internet, even LED lightbulbs — follow an S-shaped adoption curve, with EVs going from zero to 2 million in five years according to market data. Sales move at a crawl in the early-adopter phase, then surprisingly quickly once things go mainstream. (The top of the S curve represents the last holdouts who refuse to give up their old flip phones.)

Electric cars inline tout
In the case of electric vehicles, 5% seems to be the point when early adopters are overtaken by mainstream demand. Before then, sales tend to be slow and unpredictable, and still behind gas cars in most markets. Afterward, rapidly accelerating demand ensues.

It makes sense that countries around the world would follow similar patterns of EV adoption. Most impediments are universal: there aren’t enough public chargers, grid capacity concerns linger, the cars are expensive and in limited supply, buyers don’t know much about them. Once the road has been paved for the first 5%, the masses soon follow.

Thus the adoption curve followed by South Korea starting in 2021 ends up looking a lot like the one taken by China in 2018, which is similar to Norway after its first 5% quarter in 2013. The next major car markets approaching the tipping point this year include Canada, Australia, and Spain, suggesting that within a decade many drivers could be in EVs worldwide. 

 

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"Remarkable" New Contract Award Adds 10 GW of Renewables to UK Grid

UK Renewable Energy Auction secures 10 GW for the grid at record-low costs, led by offshore wind, floating wind, solar, and onshore wind, with inflation-indexed CfDs delivering £37/MWh strike prices and enhanced energy security.

 

Key Points

Government CfDs add 10 GW of low-cost renewables to the UK grid via offshore wind, floating wind, and solar.

✅ 10 GW capacity: 7 GW offshore wind, 2.2 GW solar, 0.9 GW onshore wind

✅ Record-low £37/MWh offshore; floating wind at £87/MWh CfD strikes

✅ 15-year indexed contracts cut exposure to volatile gas prices

 

The United Kingdom will add 10 gigawatts (GW) of renewable energy capacity to its power grid at one-quarter the cost of fossil gas after concluding its biggest-ever renewable energy auction for new renewable supplies.

The “remarkable new UK renewable auction” will meet one-eighth of the country’s current electricity demand at record low prices of just £37 per megawatt-hour for offshore wind and £87 for floating offshore systems (a dynamic echoed as wind power gains in Canada across other markets), tweeted Carbon Brief Deputy Editor Simon Evans.

“The government is increasing its reliance on a local supply of renewables amid soaring UK power prices driven by a surge in the cost of natural gas following Russia’s invasion of Ukraine,” Bloomberg Green reports. Offshore wind energy “will add about seven gigawatts of clean power capacity to the nation’s fleet from 2026, bringing Britain closer to its target of installing 50 gigawatts by the end of the decade.”

The awards also include 2.2 gigawatts (that’s 2.2 billion watts) of solar and 900 megawatts of onshore wind, even as the UK faces a renewables backlog on some projects, Bloomberg says.

“Eye-watering gas prices are hitting consumers across Europe,” said UK Business and Energy Secretary Kwasi Kwarteng. “The more cheap, clean power we generate within our own borders, the better protected we will be from volatile gas prices that are pushing up bills.”

Citing government figures, Bloomberg says wind generation costs came in 5.8% lower than the previous auction in 2019, reflecting momentum in a sector set to become a trillion-dollar business this decade. Some of the winning bidders included Ørsted, Iberdrola’s Scottish Power unit, Vattenfall, and a consortium of AB Ignitis Grupe, EDP Renovaveis, and Engie.

Offshore wind power costs have fallen dramatically in recent years as the UK supported the industry to scale up and industrialize production of larger, more efficient turbines,” the news story states. Now, “the decline in price developers are willing to accept comes even after the cost of wind turbines rose in recent months as prices increased for key metals like steel and supply chain disruptions created expensive delays.”

The 15-year, fixed-price contracts will be adjusted for inflation when the turbines are ready to start delivering electricity, offering lessons for the U.S. wind sector on contract design.

 

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Biden seen better for Canada’s energy sector

Biden Impact on Canadian Energy Exports highlights shifts in trade policy, tariffs, carbon pricing, and Keystone XL, with implications for aluminum, softwood lumber, electricity trade, fracking limits, and small modular nuclear reactors.

 

Key Points

How Biden-era trade, climate rules, and tariffs may reshape Canadian energy and exports.

✅ Reduced tariff volatility and friendlier trade policy toward allies

✅ Climate alignment: carbon pricing, clean power, cross-border electricity

✅ Potential gains for oil, gas, aluminum, and softwood lumber exporters

 

There is little doubt among industry associations, the Conference Board of Canada and C.D. Howe Institute that a Joe Biden White House will be better for Canadian resource and energy exporters – even Alberta’s beleaguered oil industry, despite Biden’s promise to kill the Keystone XL pipeline.

The consensus among industry observers in the lead-up to the November 3 U.S. presidential election was that a re-elected Donald Trump would become even more pugnacious on trade and protectionism, putting electricity exports at risk for Canadian utilities, which would be bad for Canadian exporters. The Justin Trudeau government would likely come under increased pressure to lower Canadian business taxes to compete with Trump’s low-tax climate.

“A Joe Biden victory would likely lead to higher taxes for both corporations and wealthy Americans to help pay down the gigantic fiscal deficit that is currently running at plus-US$5 trillion,” the conference board concluded in a recent analysis.

On trade and tariffs, the conference board said: “Many but not all of these ongoing trade disputes would wither away under a Joe Biden administration. He would likely run a broad trade policy favouring strategic allies like Canada.

While Canadian industries like forestry and aluminum smelting benefited from strong demand and prices in the U.S. under Trump, the forced renegotiation of the North American Free Trade Agreement failed end tariffs and duties on things like softwood lumber and aluminum ingots, even as Canadians backed tariffs on energy and minerals during the dispute.

The uncertainty over trade issues, and Trump’s tax cuts, which made Canada’s tax regime less competitive, have contributed to a period of low business investment in Canada during Trump's presidency.

“For Canada, we’ve seen a period, since this administration has been in power, where investment has eroded steadily,” conference board chief economist Pedro Antunes said. “We are not doing well at all, in terms of private capital investment in Canada.”

Alberta’s oil industry has been hit particularly hard, with a slew of divestments by big energy giants, and cancellations of major projects, like the $20 billion Frontier oilsands project, scrubbed by Teck Resources.

While domestic policies and global market forces are partly to blame for falling investments in Canada’s oil and gas sector, up until the pandemic hit, investment in oil and gas increased significantly in the U.S., while declining in Canada, during Trump’s first term.

Biden is also expected to level the playing field with respect to climate change policies. Canadian industries pay carbon taxes and face regulations that their counterparts in the U.S. don’t. That has disadvantaged energy-intensive, trade-exposed industries like mines and pulp mills in Canada.

“With Biden in office, Canada will once again have a partner at the federal level in the states in the transition to a decarbonized economy,” said Josha MacNab, national policy director for the Pembina Institute.

Biden’s policies might also favour importing aluminum, cross-laminated timber, fuel cells and other lower-carbon products and commodities from Canada.

At least one observer believes that Canada’s oil and gas sector might benefit more from a Biden White House, despite Biden’s pledge to kill the Keystone XL pipeline.

“I think Joe Biden could be very good for Alberta,” Christopher Sands, director of the Wilson International Center’s Canada Institute, said in a recent discussion hosted by the C.D. Howe Institute.

Sands added that the presidential permit Biden has promised to tear up on the Keystone XL pipeline project is a construction permit, not an operating permit.

“The segment of that pipeline that crosses the U.S.-Canada border, which is the only place that the presidential permit applies, has been built,” Sands said. “So I think that’s somewhat of an empty threat.”

He added that, if Biden bans fracking on federal lands, as he has promised, and implements other restrictions that make it more costly for American oil and gas producers, it might increase the demand for Canadian oil and gas in the U.S. The demand would be highest in the U.S. Midwest, which depends largely on Marcellus Shale production, notably in Pennsylvania, and Western Canada for its oil and gas.

One of the Canadian industries directly affected by the Trump administration was aluminum smelting, which is relevant for B.C. because Rio Tinto plc’s Kitimat smelter exports aluminum to the U.S.

Jean Simard, president of the Aluminum Association of Canada, said one of Trump’s legacies was the reactivation of a little-used mechanism – Section 232 of the Trade Expansion Act – to hit Canada and other countries, notably China, with import tariffs.

The 10 per cent tariffs on aluminum cost Canadian aluminum producers US$15 million in the month of August alone, Simard said.

The Trump administration eventually exempted Canadian aluminum exports from the tariffs, then reintroduced them, and then, one week before the election, exempted them again.

These on-again, off-again tariff threats create tremendous uncertainty, not just for Canadian producers, but also for U.S. buyers. That kind of uncertainty is likely to ease under a Biden presidency.

Simard said Biden’s track record suggests he is well-disposed towards Canada and less confrontational with allies and trade partners in general, and some in Washington have called for a stronger U.S.-Canada energy partnership as well.

Meanwhile, softwood lumber tariffs have been imposed by Democrats and Republicans alike. But there are compelling reasons for ending the Canada-U.S. softwood lumber war.

Home renovation and repair in the United States has done surprisingly well during the pandemic.

As a result of sawmill curtailments in the U.S. due to pandemic restrictions and high demand for lumber in the U.S. housing sector, North American lumbers prices broke records this summer, soaring as high as US$900 per thousand board feet.

“It shows that there’s very strong demand for our product,” said Susan Yurkovich, president of the Council of Forest Industries.

Ultimately, the duties Canadian lumber exporters pay are passed on to U.S. consumers.

Sands said Biden’s climate action pledges, including a clean electricity standard, could increase opportunities for trading electricity between Canada in the U.S., as the U.S. increasingly looks to Canada for green power, and could also be good for Canadian nuclear power technology.

Strong climate change policies necessarily result in an increased demand for low-carbon electricity, and advancing clean grids, which Canada has in abundance, thanks to both hydro and nuclear power.

“[Biden] does share the desire to act on climate change, but unlike some of his fellow party members who are more signed on to a Green New Deal, he’s open to pragmatic solutions that might get the job done quickly and efficiently,” Sands said.

“This is a huge opportunity for small, modular nuclear reactors, and Atomic Energy Canada has some great designs. There’s a real opportunity for a nuclear revival.” 

 

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California Takes the Lead in Electric Vehicle and Charging Station Adoption

California EV Adoption leads the U.S., with 37% of registered electric vehicles and 27% of charging locations, spanning Level 1, Level 2, and DC Fast stations, aligned with OCPI and boosted by CALeVIP funding.

 

Key Points

California EV adoption reflects the state's leading EV registrations and growth in private charging infrastructure.

✅ 37% of U.S. EVs, 27% of charging locations in 2022

✅ CALeVIP funding boosts public charging deployment

✅ OCPI-aligned data; EVs per charger rose to 75 in CA

 

California has consistently been at the forefront of electric vehicle (EV) adoption, with EV sales topping 20% in California underscoring this trend, and the proliferation of EV charging stations in the United States, maintaining this position since 2016. According to recent estimates from our State Energy Data System (SEDS), California accounts for 37% of registered light-duty EVs in the U.S. and 27% of EV charging locations as of the end of 2022.

The vehicle stock data encompass all registered on-road, light-duty vehicles and exclude any previous vehicle sales no longer in operation. The data on EV charging locations include both private and public access stations for Legacy, Level 1, Level 2, and DC Fast charging ports, excluding EV chargers in single-family residences. There is a data series break between 2020 and 2021, when the U.S. Department of Energy updated its data to align with the Open Charge Point Interface (OCPI) international standard, reflecting changes in the U.S. charging infrastructure landscape.

In 2022, the number of registered EVs in the United States, with U.S. EV sales soaring into 2024 nationwide, surged to six times its 2016 figure, growing from 511,600 to 3.1 million, while the number of U.S. charging locations nearly tripled, rising from 19,178 to 55,015. Over the same period, California saw its registered EVs more than quadruple, jumping from 247,400 to 1.1 million, and its charging locations tripled, increasing from 5,486 to 14,822.

California's share of U.S. EV registrations has slightly decreased in recent years as EV adoption has spread across the country, with Arizona EV ownership relatively high as well. In 2016, California accounted for approximately 48% of light-duty EVs in the United States, which was approximately 12 times more than the state with the second-highest number of EVs, Georgia. By 2022, California's share had decreased to around 37%, which was still approximately six times more than the state with the second-most EVs, Florida.

On the other hand, California's share of U.S. EV charging locations has risen slightly in recent years, as charging networks compete amid federal electrification efforts and partly due to the California Electric Vehicle Infrastructure Project (CALeVIP), which provides funding for the installation of publicly available EV charging stations. In 2016, approximately 25% of U.S. EV charging locations were in California, over four times as many as the state with the second-highest number, Texas. In 2022, California maintained its position with over four times as many EV charging locations as the state with the second-most, New York.

The growth in the number of registered EVs has outpaced the growth of EV charging locations in the United States, and in 2021 plug-in vehicles traveled 19 billion electric miles nationwide, underscoring utilization. In 2016, there were approximately 27 EVs per charging location on average in the country. Alaska had the highest ratio, with 67 EVs per charging location, followed by California with 52 vehicles per location.

In 2022, the average ratio was 55 EVs per charging location in the United States, raising questions about whether the grid can power an ongoing American EV boom ahead. New Jersey had the highest ratio, with 100 EVs per charging location, followed by California with 75 EVs per location.

 

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New Kind of 'Solar' Cell Shows We Can Generate Electricity Even at Night

Thermoradiative Diode Power leverages infrared radiation and night-sky cooling to harvest waste heat. Using MCT (mercury cadmium telluride) detectors with photovoltaics, it extends renewable energy generation after sunset, exploiting radiative cooling and low-power density.

 

Key Points

Technology using MCT infrared diodes to turn radiative Earth-to-space heat loss into electricity, aiding solar at night.

✅ MCT diodes radiate to cold sky, generating tiny current at 20 C

✅ Complements photovoltaics by harvesting post-sunset infrared flux

✅ Potential up to one-tenth solar output with further efficiency gains

 

Conventional solar technology soaks up rays of incoming sunlight to bump out a voltage. Strange as it seems, some materials are capable of running in reverse, producing power as they radiate heat back into the cold night sky environment.

A team of engineers in Australia has now demonstrated the theory in action, using the kind of technology commonly found in night-vision goggles to generate power, while other research explores electricity from thin air concepts under ambient humidity.

So far, the prototype only generates a small amount of power, and is probably unlikely to become a competitive source of renewable power on its own – but coupled with existing photovoltaics technology and thermal energy into electricity approaches, it could harness the small amount of energy provided by solar cells cooling after a long, hot day's work.

"Photovoltaics, the direct conversion of sunlight into electricity, is an artificial process that humans have developed in order to convert the solar energy into power," says Phoebe Pearce, a physicist from the University of New South Wales.

"In that sense, the thermoradiative process is similar; we are diverting energy flowing in the infrared from a warm Earth into the cold Universe."

By setting atoms in any material jiggling with heat, you're forcing their electrons to generate low-energy ripples of electromagnetic radiation in the form of infrared light, a principle also explored with carbon nanotube energy harvesters in ambient conditions.

As lackluster as this electron-shimmy might be, it still has the potential to kick off a slow current of electricity. All that's needed is a one-way electron traffic signal called a diode.

Made of the right combination of elements, a diode can shuffle electrons down the street as it slowly loses its heat to a cooler environment.

In this case, the diode is made of mercury cadmium telluride (MCT). Already used in devices that detect infrared light, MCT's ability to absorb mid-and long-range infrared light and turn it into a current is well understood.

What hasn't been entirely clear is how this particular trick might be used efficiently as an actual power source.

Warmed to around 20 degrees Celsius (nearly 70 degrees Fahrenheit), one of the tested MCT photovoltaic detectors generated a power density of 2.26 milliwatts per square meter.

Granted, it's not exactly enough to boil a jug of water for your morning coffee. You'd probably need enough MCT panels to cover a few city blocks for that small task.

But that's not really the point, either, given it's still very early days in the field, and there's potential for the technology to develop significantly further in the future.

"Right now, the demonstration we have with the thermoradiative diode is relatively very low power. One of the challenges was actually detecting it," says the study's lead researcher, Ned Ekins-Daukes.

"But the theory says it is possible for this technology to ultimately produce about 1/10th of the power of a solar cell."

At those kinds of efficiencies, it might be worth the effort weaving MCT diodes into more typical photovoltaic networks alongside thin-film waste heat solutions so that they continue to top up batteries long after the Sun sets.

To be clear, the idea of using the planet's cooling as a source of low-energy radiation is one engineers have been entertaining for a while now. Different methods have seen different results, all with their own costs and benefits, with low-cost heat-to-electricity materials also advancing in parallel.

Yet by testing the limits of each and fine-tuning their abilities to soak up more of the infrared bandwidth, we can come up with a suite of technologies and thermoelectric materials capable of wringing every drop of power out of just about any kind of waste heat.

"Down the line, this technology could potentially harvest that energy and remove the need for batteries in certain devices – or help to recharge them," says Ekins-Daukes.

"That isn't something where conventional solar power would necessarily be a viable option."

 

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World Bank helps developing countries wind spurt

World Bank Offshore Wind Investment drives renewables and clean energy in developing countries, funding floating turbines and shallow-water foundations to replace fossil fuels, expand grids, and scale climate finance across Latin America, Africa, and Asia.

 

Key Points

A World Bank program funding offshore wind to speed clean power, cut fossil fuels, and expand grids in emerging markets.

✅ US$80bn to 565 onshore wind projects since 1995

✅ Pilot funds offshore wind in Asia, Africa, Latin America

✅ Floating turbines and shallow-water foundations enable deep resources

 

Europe and the United States now accept onshore wind power as the cheapest way to generate electricity, and U.S. lessons from the U.K. are informing policy discussions. But this novel technology still needs subsidising before some developing countries will embrace it. Enter the World Bank.

A total of US$80 billion in subsidies from the Bank has gone over 25 years to 565 developing world onshore wind projects, to persuade governments to invest in renewables rather than rely on fossil fuels.

Central and Latin American countries have received the lions share of this investment, but the Asia Pacific region and Eastern Europe have also seen dozens of Bank-funded developments. Now the fastest-growing market is in Africa and the Middle East, where West African hydropower support can complement variable wind resources.

But while continuing to campaign for more onshore wind farms, the World Bank in 2019 started encouraging target countries to embrace offshore wind as well. This uses two approaches: turbines in shallow water, which are fixed to the seabed, and also a newer technology, involving floating turbines anchored by cables at greater depth.

The extraordinary potential for offshore wind, which is being commercially developed very fast in Europe, including the UK's offshore expansion, China and the U.S. offshore wind sector today as well, is now seen by the Bank as important for countries like Vietnam which could harness enough offshore wind power to provide all its electricity needs.

Other countries it has identified with enormous potential for offshore wind include Brazil, Indonesia, India, the Philippines, South Africa and Sri Lanka, all of them countries that need to keep building more power stations to connect every citizen to the national grid.

The Bank began investing in wind power in 1995, with its spending reaching billions of dollars annually in 2011. The biggest single recipient has been Brazil, receiving US$24.2 bn up to the end of 2018, 30 per cent of the total the Bank has invested worldwide.

Many private companies have partnered with the Bank to build the wind farms. The biggest single beneficiary is Enel, the Italian energy giant, which has received US$6.1 bn to complete projects in Brazil, Mexico, South Africa, Romania, Morocco, Bulgaria, Peru, and Russia.

Among the countries now benefitting from the Banks continuing onshore wind programme are Egypt, Morocco, Senegal, Jordan, Vietnam, Thailand, Indonesia and the Philippines.

Offshore wind now costs less than nuclear power, and global costs have fallen enough to compete in most countries with fossil fuels. Currently the fastest-growing industry in the world, it continued to grow despite Covid-19 across most markets.

Persistent coal demand

Particularly in Asia, some countries are continuing to burn large quantities of coal and are considering investing in yet more fossil fuel generation unless they can be persuaded that renewables are a better option, with an offshore wind $1 trillion outlook underscoring the scale.

Last year the World Bank began a pilot scheme to explore funding investment in offshore wind in these countries. Launching the scheme Riccardo Puliti, a senior director at the Bank, said: Offshore wind is a clean, reliable and secure source of energy with massive potential to transform the energy mix in countries that have great wind resources.

We have seen it work in Europe we can now make use of global experience to scale up offshore wind projects in emerging markets.

Using data from the Global Wind Atlas, the Bank calculated that developing countries with shallow waters like India, Turkey and Sri Lanka had huge potential with fixed turbines, while others the Philippines and South Africa, for example would need floating foundations to reach greater depths, up to 1,000 metres.

For countries like Vietnam, with a mix of shallow and deep water, wind power could solve their entire electricity needs. In theory offshore wind power could produce ten times the amount of electricity that the country currently gets from all its current power stations, the Bank says.

 

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Electric Cars 101: How EV Motors Work, Tech Differences, and More

Electric Car Motors convert electricity to torque via rotor-stator magnetic fields, using AC/DC inverters, permanent magnets or induction designs; they power EV powertrains efficiently and enable regenerative braking for energy recovery and control.

 

Key Points

Electric car motors turn electrical energy into wheel torque using rotor-stator fields, inverters, and AC or DC control.

✅ AC induction, PMSM, BLDC, and reluctance architectures explained

✅ Inverters manage AC/DC, voltage, and motor speed via frequency

✅ Regenerative braking recovers energy and reduces wear

 

When was the last time you stopped to think about how electric cars actually work, especially if you're wondering whether to buy an electric car today? We superfans of the car biz have mostly developed a reasonable understanding of how combustion powertrains work. Most of us can visualize fuel and air entering a combustion chamber, exploding, pushing a piston down, and rotating a crankshaft that ultimately turns the wheels. We generally understand the differences between inline, flat, vee-shaped, and maybe even Wankel rotary combustion engines.

Mechanical engineering concepts such as these are comparatively easy to comprehend. But it's probably a fair bet to wager that only a minority of folks reading this can explain on a bar napkin exactly how invisible electrons turn a car's wheels or how a permanent-magnet motor differs from an AC induction one. Electrical engineering can seem like black magic and witchcraft to car nuts, so it's time to demystify this bold new world of electromobility, with the age of electric cars arriving ahead of schedule.

How Electric Cars Work: Motors
It has to do with magnetism and the natural interplay between electric fields and magnetic fields. When an electrical circuit closes allowing electrons to move along a wire, those moving electrons generate an electromagnetic field complete with a north and a south pole. When this happens in the presence of another magnetic field—either from a different batch of speeding electrons or from Wile E. Coyote's giant ACME horseshoe magnet, those opposite poles attract, and like poles repel each other.


 

Electric motors work by mounting one set of magnets or electromagnets to a shaft and another set to a housing surrounding that shaft. By periodically reversing the polarity (swapping the north and south poles) of one set of electromagnets, the motor leverages these attracting and repelling forces to rotate the shaft, thereby converting electricity into torque and ultimately turning the wheels, in a sector where the electric motor market is growing rapidly worldwide. Conversely—as in the case of regenerative braking—these magnetic/electromagnetic forces can transform motion back into electricity.

How Electric Cars Work: AC Or DC?
The electricity supplied to your home arrives as alternating current (AC), and bidirectional charging means EVs can power homes for days as needed, so-called because the north/south or plus/minus polarity of the power changes (alternates) 60 times per second. (That is, in the United States and other countries operating at 110 volts; countries with a 220-volt standard typically use 50-Hz AC.) Direct current (DC) is what goes into and comes out of the + and - poles of every battery. As noted above, motors require alternating current to spin. Without it, the electromagnetic force would simply lock their north and south poles together. It's the cycle of continually switching north and south that keeps a motor spinning.


 

Today's electric cars are designed to manage both AC and DC energy on board. The battery stores and dispenses DC current, but again, the motor needs AC. When recharging the battery, and with increasing grid coordination enabling flexibility, the energy comes into the onboard charger as AC current during Level 1 and Level 2 charging and as DC high-voltage current on Level 3 "fast chargers." Sophisticated power electronics (which we will not attempt to explain here) handle the multiple onboard AC/DC conversions while stepping the voltage up and down from 100 to 800 volts of charging power to battery/motor system voltages of 350-800 volts to the many vehicle lighting, infotainment, and chassis functions that require 12-48-volt DC electricity.

How Electric Cars Work: What Types Of Motors?
DC Motor (Brushed): Yes, we just said AC makes the motor go around, and these old-style motors that powered early EVs of the 1900s are no different. DC current from the battery is delivered to the rotor windings via spring-loaded "brushes" of carbon or lead that energize spinning contacts connected to wire windings. Every few degrees of rotation, the brushes energize a new set of contacts; this continually reverses the polarity of the electromagnet on the rotor as the motor shaft turns. (This ring of contacts is known as the commutator).

The housing surrounding the rotor's electromagnetic windings typically features permanent magnets. (A "series DC" or so-called "universal motor" may use an electromagnetic stator.) Advantages are low initial cost, high reliability, and ease of motor control. Varying the voltage regulates the motor's speed, while changing the current controls its torque. Disadvantages include a lower lifespan and the cost of maintaining the brushes and contacts. This motor is seldom used in transportation today, save for some Indian railway locomotives.

Brushless DC Motor (BLDC): The brushes and their maintenance are eliminated by moving the permanent magnets to the rotor, placing the electromagnets on the stator (housing), and using an external motor controller to alternately switch the various field windings from plus to minus, thereby generating the rotating magnetic field.

Advantages are a long lifespan, low maintenance, and high efficiency. Disadvantages are higher initial cost and more complicated motor speed controllers that typically require three Hall-effect sensors to get the stator-winding current phased correctly. That switching of the stator windings can result in "torque ripple"—periodic increases and decreases in the delivered torque. This type of motor is popular for smaller vehicles like electric bikes and scooters, and it's used in some ancillary automotive applications like electric power steering assist.


 

Permanent-Magnet Synchronous Motor (PMSM): Physically, the BLDC and PMSM motors look nearly identical. Both feature permanent magnets on the rotor and field windings in the stator. The key difference is that instead of using DC current and switching various windings on and off periodically to spin the permanent magnets, the PMSM functions on continuous sinusoidal AC current. This means it suffers no torque ripple and needs only one Hall-effect sensor to determine rotor speed and position, so it's more efficient and quieter.

The word "synchronous" indicates the rotor spins at the same speed as the magnetic field in the windings. Its big advantages are its power density and strong starting torque. A main disadvantage of any motor with spinning permanent magnets is that it creates "back electromotive force" (EMF) when not powered at speed, which causes drag and heat that can demagnetize the motor. This motor type also sees some duty in power steering and brake systems, but it has become the motor design of choice in most of today's battery electric and hybrid vehicles.


 

Note that most permanent-magnet motors of all kinds orient their north-south axis perpendicular to the output shaft. This generates "radial (magnetic) flux." A new class of "axial flux" motors orients the magnets' N-S axes parallel to the shaft, usually on pairs of discs sandwiching stationary stator windings in between. The compact, high-torque axial flux orientation of these so-called "pancake motors" can be applied to either BLDC or PMSM type motors.


 

AC Induction: For this motor, we toss out the permanent magnets on the rotor (and their increasingly scarce rare earth materials) and keep the AC current flowing through stator windings as in the PMSM motor above.

Standing in for the magnets is a concept Nikola Tesla patented in 1888: As AC current flows through various windings in the stator, the windings generate a rotating field of magnetic flux. As these magnetic lines pass through perpendicular windings on a rotor, they induce an electric current. This then generates another magnetic force that induces the rotor to turn. Because this force is only induced when the magnetic field lines cross the rotor windings, the rotor will experience no torque or force if it rotates at the same (synchronous) speed as the rotating magnetic field.

This means AC induction motors are inherently asynchronous. Rotor speed is controlled by varying the alternating current's frequency. At light loads, the inverter controlling the motor can reduce voltage to reduce magnetic losses and improve efficiency. Depowering an induction motor during cruising when it isn't needed eliminates the drag created by a permanent-magnet motor, while dual-motor EVs using PMSM motors on both axles must always power all motors. Peak efficiency may be slightly greater for BLDC or PMSM designs, but AC induction motors often achieve higher average efficiency. Another small trade-off is slightly lower starting torque than PMSM. The GM EV1 of the mid-1990s and most Teslas have employed AC Induction motors, despite skepticism about an EV revolution in some quarters.


 

Reluctance Motor: Think of "reluctance" as magnetic resistance: the degree to which an object opposes magnetic flux. A reluctance motor's stator features multiple electromagnet poles—concentrated windings that form highly localized north or south poles. In a switched reluctance motor (SRM), the rotor is made of soft magnetic material such as laminated silicon steel, with multiple projections designed to interact with the stator's poles. The various electromagnet poles are turned on and off in much the same way the field windings in a BLDC motor are. Using an unequal number of stator and rotor poles ensures some poles are aligned (for minimum reluctance), while others are directly in between opposite poles (maximum reluctance). Switching the stator polarity then pulls the rotor around at an asynchronous speed.


 

A synchronous reluctance motor (SynRM) doesn't rely on this imbalance in the rotor and stator poles. Rather, SynRM motors feature a more distributed winding fed with a sinusoidal AC current as in a PMSM design, with speed regulated by a variable-frequency drive, and an elaborately shaped rotor with voids shaped like magnetic flux lines to optimize reluctance.

The latest trend is to place small permanent magnets (often simpler ferrite ones) in some of these voids to take advantage of both magnetic and reluctance torque while minimizing cost and the back EMF (or counter-electromotive force) high-speed inefficiencies that permanent-magnet motors suffer.

Advantages include lower cost, simplicity, and high efficiency. Disadvantages can include noise and torque ripple (especially for switched reluctance motors). Toyota introduced an internal permanent-magnet synchronous reluctance motor (IPM SynRM) on the Prius, and Tesla now pairs one such motor with an AC induction motor on its Dual Motor models. Tesla also uses IPM SynRM as the single motor for its rear-drive models.


 

Electric motors may never sing like a small-block or a flat-plane crank Ferrari. But maybe, a decade or so from now, we'll regard the Tesla Plaid powertrain as fondly as we do those engines, even as industry leaders note that mainstream adoption faces hurdles, and every car lover will be able to describe in intimate detail what kind of motors it uses.
 

 

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