Within A Decade, We Will All Be Driving Electric Cars

NC WARN Solar Case tests third-party solar rights as North Carolina Supreme Court reviews Utilities Commission fines over a Greensboro church's rooftop power deal, challenging Duke Energy's monopoly, onsite electricity sales, and potential rate impacts.

Key Points

A North Carolina Supreme Court test of third-party solar could weaken Duke Energy's monopoly and change utility rules.

✅ NC Supreme Court weighs Utilities Commission penalty on NC WARN

✅ Case could permit onsite third-party solar sales statewide

✅ Outcome may pressure Duke Energy's monopoly and rates

North Carolina's highest court is taking up a case that could force new competition on the state's electricity monopolies.

The state Supreme Court on Tuesday will consider the Utilities Commission's decision to fine clean-energy advocacy group NC WARN for putting solar panels on a Greensboro church's rooftop and then charging it below-market rates for power.

The commission told NC WARN that it was producing electricity illegally and fined the group $60,000. The group said it was acting privately and appealed to the high court.

If the group prevails, it could put new pressure on Duke Energy's monopoly, which has seen an oversubscribed solar solicitation in recent procurements. State regulators say a ruling for NC WARN would allow companies to install solar equipment and sell power on site, shaving away customers and forcing Duke Energy to raise rates on everyone else.

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That's because if NC WARN's deal with Faith Community Church is allowed, the precedent could open the door for others to lure away from Duke Energy, as debates over how solar owners are paid continue, "the customers with the highest profit potential, such as commercial and industrial customers with large energy needs and ample rooftop space," attorney Robert Josey Jr. wrote in a court filing.

Losing those power sales would force the country's No. 2 electricity company to make it up by charging remaining customers more to cover the cost of all of its power plants, transmission lines and repair crews, a dynamic echoed in New England's grid upgrade debates as solar grows, wrote Josey, an attorney for the Public Staff, the state's official utilities consumer advocate.

The dispute is whether NC WARN is producing electricity "for the public," which would mean it's intruding on the territory of the publicly regulated monopoly utility, or whether the move was allowed because it was a private power deal with the church alone.

NC WARN installed the church's power panels in 2015 as part of what it described as a test case, amid wider debates like Nova Scotia's delayed solar charge for customers, challenging Duke Energy's monopoly position to generate and sell electricity.

North Carolina was one of nine states that as of last year explicitly disallowed residential customers from buying electricity generated by solar panels on their roof from a third party that owns the system, even as Maryland opens solar subscriptions more broadly, according to the North Carolina Clean Energy Technology Center. State law allows purchased or leased solar panels, but not payments simply for the power they generate.

NC WARN's goals included "reducing the effects of Duke Energy's monopoly control that has such negative impacts on power bills, clean air and water, and climate change," the church's pastor, Rev. Nelson Johnson, said in a statement the same day the clean-energy group asked state regulators to clear the plan.

Instead, the North Carolina Utilities Commission ruled the arrangement violated the state's system of legal electricity monopolies and hit the group with nearly $60,000 in fines, which would be suspended if the church's payments were refunded with interest and the solar equipment donated. The group has set aside the money and will donate the gear if it loses the Supreme Court case, NC WARN Executive Director Jim Warren said.

NC WARN's three-year agreement saw the group mount a rooftop solar array for which the church would pay about half the average retail electricity price, state officials said. The agreement states plainly that it is not a contract for the sale or lease of the $20,000 solar system, the church never owns the panels, and the low electricity price means its payback for the equipment would take 60 years, Josey wrote.

"Clearly, the only thing of value (the church) is obtaining for its payments under this agreement is the electricity created," he wrote.

In court filings, the group's attorneys have stuck to the argument that NC WARN isn't selling to the public because the deal involved a single customer only.

The deal "is not open to any other member of the public ... A private, bargained-for contract under which only one party receives electricity is not a sale of electricity 'to or for the public,' " attorney Matthew Quinn wrote to the court.

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Inflation Reduction Act Energy Credits help households electrify with tax credits and rebates for heat pumps, EVs, rooftop solar, battery storage, and efficiency upgrades, cutting utility bills, reducing carbon emissions, and accelerating home electrification nationwide.

Key Points

Federal incentives offering tax credits and rebates for heat pumps, EVs, solar, and efficiency to cut emissions.

✅ 30% rooftop solar and storage credit; $2,000 annual cap for heat pumps

✅ Up to $7,500 EV tax credit; price, income, and assembly rules apply

✅ Low-income rebates and discounts available via states starting mid-2023

Earlier this year, Congress passed the biggest climate bill in history — cloaked under the name the “Inflation Reduction Act,” a historic climate deal by any measure.

Starting in the new year, the bill will offer households thousands of dollars to transition over from fossil-fuel burning heaters, stoves and cars to cleaner versions as renewable electricity accelerates. On Jan. 1, middle-income households will be able to access over a half-dozen tax credits for electric stoves, cars, rooftop solar and more. And starting sometime in mid-2023, lower-income households will be able to get upfront discounts on some of those same appliances — without having to wait to file their taxes to get the cash back. This handy online tool shows what you might be eligible for, depending on your Zip code and income.

But which credits should Americans focus on — and which are best for the climate? Here’s a guide to the top climate-friendly benefits of the Inflation Reduction Act, and how to access them.

Heat pumps — the best choice for decarbonizing at home

Tax credit available on Jan. 1: 30 percent of the cost, up to $2,000

Income limit: None

Ah, heat pumps — one of the most popular technologies of the transition to clean energy and to net-zero electricity systems. “Heat pump” is a bit of a misnomer for these machines, which are more like super-efficient combo air conditioning and heating systems. These appliances run on electricity and move heat, instead of creating it, and so can be three to five times more efficient than traditional gas or electrical resistance heaters.

“For a lot of people, a heat pump is going to be their biggest personal impact,” said Sage Briscoe, the federal senior policy manager at Rewiring America, a clean-energy think tank. (Heat pumps have become so iconic that Rewiring America even has a heat pump mascot.)

Heat pumps can have enormous cost and carbon savings. According to one analysis using data from the National Renewable Energy Laboratory, switching to a heat pump can save homeowners anywhere from $100 to $1,200 per year on heating bills and prevent anywhere from 1 to 8 metric tons of carbon dioxide emissions per year. For comparison, going vegan for an entire year saves about 1 metric ton of CO2 emissions.

But many consumers encounter obstacles when switching over to heat pumps. In some areas, it can be difficult to find a contractor trained and willing to install them; some homeowners report that contractors share misinformation about heat pumps, including that they don’t work in cold climates. (Modern heat pumps do work in cold climates, and can heat a home even when outdoor temperatures are down to minus-31 degrees Fahrenheit.) Briscoe recommends that homeowners look for skilled contractors who know about heat pumps and do advance research to figure out which models might work best for their home.

Electric vehicles — top choice for cutting car emissions

Tax credit available on Jan. 1: Up to $7,500 depending on the make and model of the car

Income limit: <$150,000 for single filers; <$300,000 for joint filers

If you are like the millions of Americans who don’t live in a community with ample public transit, the best way to decarbonize your transport, as New Zealand's electricity transition shows, is switching to an electric car. But electric cars can be prohibitively expensive for many Americans.

Starting Jan. 1, a new EV tax credit will offer consumers up to $7,500 off the purchase of an electric vehicle. For the first few months, Americans will get somewhere between $3,751 and $7,500 off their purchase of an EV, depending on the size of the battery in the car.

There are limitations, per the new law. The vehicles will also have to be assembled in North America, where Canada's electricity progress is notable, and cars that cost more than $55,000 aren’t eligible, nor are vans or trucks that cost more than $80,000. This week, the Internal Revenue Service provided a list of vehicles that are expected to meet the criteria starting Jan. 1.

Beginning about March, however, that $7,500 credit will be split into two parts: Consumers can get a $3,750 credit if the vehicle has a battery containing at least 40 percent critical minerals from the United States (or a country that the United States has a free-trade agreement with) and another $3,750 credit if at least 50 percent of the battery’s components were assembled and manufactured in North America. Those rules haven’t been finalized yet, so the tax credit starting on Jan. 1 is a stopgap measure until the White House has ironed out the final version.

Joe Britton, the executive director of the EV industry group Zeta, said that means there will likely be a wider group of vehicles eligible for the full tax credit in January and February than there will be later in 2023. Because of this, he recommended that potential EV owners act fast in 2023.

“I would be buying a car in the first quarter,” he said.

Rooftop solar — the best choice for generating clean energy

Tax credit available now: 30 percent of the cost of installation, no cap

Income limit: None

For those who want to generate their own clean energy, there is always rooftop solar panels. This tax credit has actually been available since the Inflation Reduction Act was signed into law in August 2022. It offers a tax credit equal to 30 percent of the cost of installing rooftop solar, with no cap. According to Rewiring America, the average 6 kilowatt solar installation costs about $19,000, making the average solar tax credit about $5,700. (The Inflation Reduction Act also includes a 30 percent tax credit for homeowners that need to upgrade their electricity panel for rooftop solar, and a 30 percent tax credit for installing battery storage to support the shift toward carbon-free electricity solutions.)

Solar panels can save homeowners tens of thousands of dollars in utility bills as extreme heat boosts electricity bills and, when combined with battery storage, can also provide a power backup in the case of a blackout or other disaster. For someone trying to move their entire home away from fossil fuels, solar panels become even more enticing: Switch everything over to electricity, and then make the electricity super cheap with the help from the sun.

For people who don’t own their own homes, there are other options as well. Renters can subscribe to a community solar project to lower their electricity bills and get indirect benefits from the tax credits.

Tips, tricks and words of caution
There are many other credits also coming out in 2023: for EV chargers (up to $1,000), a boon for expanding carbon-free electricity across the grid, heat pump water heaters (up to $2,000), and even cash for sealing up the doors and windows of your home (up to $1,200).

The most important thing to know, Briscoe said, is whether you qualify for the upfront discounts for low- and moderate-income Americans — which won’t be available until later in 2023 — or the tax credits, which will be available Jan. 1. (Try this tool.) If going the tax credit route, it’s better to spread the upgrades out across multiple years, since there is an annual limit on how many of the credits you can claim in a given year. And, she warned, it is not always going to be easy: It can be hard to find the right installers and the right information for how to make use of all the available government resources.

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EV Charging Coal and Oil Claim: Fact-check of kWh, CO2 emissions, and electricity grid mix shows 70 lb coal or ~8 gallons oil per 66 kWh, with renewables and natural gas reducing lifecycle emissions.

Key Points

A viral claim on EV charging overstates oil use; accurate figures depend on grid mix: ~70 lb coal or ~8 gallons oil.

✅ About 70 lb coal or ~8 gal oil per 66 kWh, incl. conversion losses

✅ EVs average ~100 g CO2 per mile vs ~280 g for 30 mpg cars

✅ Grid mix includes renewables, nuclear, natural gas; oil use is low

The claim: Average electric car requires equivalent of 85 pounds of coal or six barrels of oil for a single charge

The Biden administration has pledged to work towards decarbonizing the U.S. electricity grid by 2035. And the recently passed $1.2 trillion infrastructure bill provides funding for more electric vehicle (EV) charging infrastructure, including EV charging networks across the country under current plans.

However, a claim that electric cars require an inordinate amount of oil or coal energy to charge has appeared on social media, even as U.S. plug-ins traveled 19 billion miles on electricity in 2021.

“An average electric car takes 66 KWH To charge. It takes 85 pounds of coal or six barrels of oil to make 66 KWH,” read a Dec 1 Facebook post that was shared nearly 500 times in a week. “Makes absolutely no sense.” 

The post included a stock image of an electric car charging, though actual charging costs depend on local rates and vehicle efficiency.

This claim is in the ballpark for the coal comparison, but the math on the oil usage is wildly inaccurate.

It would take roughly 70 pounds of coal to produce the energy required to charge a 66 kWh electric car battery, said Ian Miller, a research associate at the MIT Energy Initiative. That's about 15 pounds less than is claimed in the post.

The oil number is much farther off.

While the post claims that it takes six barrels of oil to charge a 66 kWh battery, Miller said the amount is closer to 8 gallons  — the equivalent of 20% of one barrel of oil.

He said both of his estimates account for energy lost when fossil fuels are converted into electricity. 

"I think the most important question is, 'How do EVs and gas cars compare on emissions per distance?'," said Miller. "In the US, using average electricity, EVs produce roughly 100 grams of CO2 per mile."

He said this is more than 60% less than a typical gasoline-powered car that gets 30 mpg, aligning with analyses that EVs are greener in all 50 states today according to recent studies. Such a vehicle produces roughly 280 grams of CO2 per mile.

Lifecycle analyses also show that the CO2 from making an EV battery is not equivalent to driving a gasoline car for years, which often counters common misconceptions.

"If you switch to an electric vehicle, even if you're using fossil fuels (to charge), it's just simply not true that you'll be using more fossil fuel," said Jessika Trancik, a professor at the Massachusetts Institute of Technology who studies the environmental impact of energy systems.  

However, she emphasized electric cars in the U.S. are not typically charged using only energy from coal or oil, and that electricity grids can handle EVs with proper management.

The U.S. electricity grid relies on a diversity of energy sources, of which oil and coal together make up about 20 percent, according to a DOE spokesperson. This amount is likely to continue to drop as renewable energy proliferates in the U.S., even as some warn that state power grids will be challenged by rapid EV adoption. 

"Switching to an electric vehicle means that you can use other sources, including less carbon-intensive natural gas, and even less carbon-intensive electricity sources like nuclear, solar and wind energy, which also carry with them health benefits in the form of reduced air pollutant emissions," said Trancik. 

Our rating: Partly false
Based on our research, we rate PARTLY FALSE the claim that the average electric car requires the equivalent of 85 pounds of coal or six barrels of oil for a single charge. The claim is in the ballpark on coal consumption, as an MIT researcher estimates that around 70 pounds. But the oil usage is only about 8 gallons, which is 20% of one barrel. And the actual sources of energy for an electric car vary depending on the energy mix in the local electric grid. 

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Canada EV Incentives drive adoption toward the 2035 zero-emission target, with rebates, federal and provincial programs boosting affordability amid concerns over charging infrastructure, range anxiety, and battery life, according to a BNN Bloomberg-Leger survey.

Key Points

Canada EV incentives are rebates and tax credits reducing EV costs to accelerate zero-emission vehicle adoption nationwide.

✅ Federal and provincial rebates reduce EV purchase prices

✅ Incentives offset range, battery, and charging concerns

✅ Larger incentives correlate with higher adoption rates

If the federal government wants to meet its ambitious EV goals of having all cars and passenger trucks sold in Canada be zero emissions by 2035, it’s going to have to do something about the cost of these vehicles.

A new survey from BNN Bloomberg and RATESDOTCA has found that cost is the number one reason stopping Canadians from buying an electric car.

The survey, which was conducted by Leger Marketing earlier this month, asked 1,511 Canadians if they were planning to purchase a new electric vehicle in the near future. It found that just over one in four, or 26 per cent of Canadians, are planning to do so, with Atlantic Canada lagging other regions. On the other hand, 19 per cent of Canadians are planning to buy a gas/diesel/hybrid card for their next purchase. 

Those who aren’t planning on buying an EV were asked what the biggest reason for their decision was. By far, it was the price of these vehicles: 31 per cent of this group cited cost as the main reason for not electrifying their ride. Another 59 per cent of respondents cited it as a concern, but not the main one. Other reasons for not wanting to buy an electric vehicle included lack of infrastructure (18 per cent), range concerns (16 per cent), and battery life and replacement (13 per cent), and some report EV shortages and wait times too.

What’s interesting is that it’s clear that government incentives for EVs are the most powerful tool right now to drive adoption, though some argue subsidies are a bad idea for Canada. When asked if further government incentives would convince them to buy an electric vehicle, 78 per cent of those surveyed said yes.

That’s right. If more governments increased the incentives offered for buying electric vehicles, reaching the goal of only selling zero emission vehicles in Canada by 2035 would no longer be a pipe dream, despite 2035 mandate skepticism from some.

At the moment, only Quebec and B.C. offer government incentives to buy an electric vehicle, even as B.C. charging bottlenecks are predicted. The federal government offers up to a $5,000 incentive, with restrictions including a limit on the total price of the vehicle, and has signaled EV sales regulations are forthcoming. Ontario previously offered a rebate of up to $14,000, however, the popular program was cancelled when the Progress Conservative government was elected in 2018.

The cancellation led to a plunge in new electric vehicle sales in Ontario, falling more than 55 per cent in the first six months of 2019 when compared to the same time period in the previous year, according to Electric Mobility Canada.

It’s no surprise that the larger the incentive, the more Canadians will be swayed to buy an electric car. Perhaps what’s surprising is that the incentive doesn’t even have to be as large as the previous Ontario rebate was. The survey found that seven per cent of Canadians would buy an electric vehicle if they got an incentive ranging anywhere from $5,001-$7,250. A full 35 per cent said a $12,500 or higher incentive would convince them.

The majority of Canadians surveyed said they use their vehicles for leisure or commuting to work. Leisure uses include running errands and seeing friends and family, of which 43 per cent of respondents said was the primary way they used their vehicle. Meanwhile, 36 per cent said they primarily used their car to commute to work.

The survey also found that incentives were more effective at convincing younger people to buy an electric vehicle. Eighty-three per cent of those under the age of 55 could be swayed by new incentives. But for those over 55, only 66 per cent said they would change their mind. 

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Bimbo Canada VPPAs secure renewable electricity from RES wind and solar projects in Alberta, totaling 170MW, via 15-year contracts to offset consumption, advance RE100 goals, and drive decarbonization across bakeries, depots, and distribution centers.

Key Points

Virtual power purchase agreements sourcing wind and solar to offset Bimbo Canadas electricity and support RE100.

✅ 15-year RES contracts for Alberta wind and solar capacity

✅ Offsets electricity for bakeries, depots, and distribution centers

✅ Advances Grupo Bimbo RE100 target for 100% renewable power

Canada's oldest and largest bakery, Bimbo Canada, has signed two virtual power purchase agreements (VPPAs) with Renewable Energy Systems  (RES) to procure renewable electricity, similar to federal green electricity contracts advancing in Alberta, that will offset 100 per cent of the company's electricity consumption in Canada. The projects are expected to be fully operational by December, 2022.

Canada is the second market, alongside the United States, to enter into VPPAs, where companies like Amazon clean energy projects are expanding rapidly. These agreements, together with additional sustainability initiatives conducted around the world by the parent company Grupo Bimbo, will help the company offset 90 per cent of its global electricity consumption.

"Bimbo Canada is committed to nourishing a better world through productive sustainability practices," said Joe McCarthy, president of Bimbo Canada. "These agreements are the next big step in reducing our environmental footprint, as peers such as Arvato's first solar plant signal industry momentum, and becoming leaders in responsible stewardship of the environment."

The 15-year agreements with RES will support the commercial development of two renewable energy projects in southern Alberta, consisting of wind and solar projects, similar to RBC's solar PPA announced in the region, totaling 170MW of installed capacity. Under these two agreements, Bimbo Canada will procure the benefit of approximately 50MW of renewable electricity to offset electricity consumption for its 16 bakeries, 14 distribution centres and 191 depots. Commercial development for the wind and solar farms will be finalized later this year by RES Canada and the projects are expected to be fully operational by the end of next year.  

"RES is proud that its Alberta wind and solar projects, amid growth such as a $200M Alberta wind farm led by a Buffett-linked firm, are helping Bimbo Canada meet its sustainability initiatives," said Peter Clibbon, RES Senior VP of Development. "It's a win-win situation with our projects delivering competitive wind and solar electricity to Bimbo Canada, and while providing our host communities with long-term tax and landowner income."

In 2018, Grupo Bimbo joined RE100, a global initiative led by The Climate Group and in partnership with Carbon Disclosure Project (CDP) and committed to operating with 100 per cent renewable electricity by 2025. As a leading supplier of fresh-baked goods and snacks for Canadian families, these agreements support the company's targets and builds upon many successful past sustainability initiatives, as market activity by Canadian Solar project sales continues nationwide.

"The renewable electricity initiatives in our operations respond to Grupo Bimbo's deep commitment that we have had for many decades globally with the planet and with present and future generations," said Daniel Servitje, global CEO of Grupo Bimbo. "With this announcement, we have achieved another important milestone for the company on our journey towards becoming 100 per cent renewable electricity by 2025."

Last year, Bimbo Canada reduced product waste and exceeded its product waste reduction target by 18 per cent, which saved four million units of products from landfills. The company also eliminated 174 metric tonnes of plastic per year (equal to 43 adult elephants) through several packaging optimization initiatives.

Earlier this year, Bimbo Canada signed the Canada Plastics Pact (CPP) and, amid a broader push for clean energy exemplified by Edmonton rooftop solar installations, earned its first ENERGY STAR certification for its Hamilton, Ontario bakery. The company will continue to work towards other initiatives that fulfill its commitment to be a sustainable, highly productive and deeply humane company.

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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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