Battery Metals

Optimizing the electrical power grid has always been a difficult task because its state is constantly changing. Now electric power systems all over the world are transitioning from highly centralized infrastructures with bulk generation plants to increasingly distributed generation and storage solutions.

The driver is the ambition to render the electric power supply more sustainable by integrating green energy into the grid. But the growing penetration of wind and solar generation also increases the challenge of balancing their variable output. So, when it comes to mastering the operation of the future power grid, do we need local intelligence or centralized decision-making? The answer is both – and other skills as well.

Hydropower plants and storage devices of all sizes are perfect balancing resources, but consumers will also play an important role: New technologies allow the consumers to use energy more efficiently and smartly and thereby participate in the load balancing process. Consequently, there will be flexible resources spread throughout the grid, from the high-voltage system down to the low-voltage system. Naturally, we will want to use the capabilities of all of these resources as efficiently as possible, but there will be literally millions of them. So one of the main challenges will be finding a way to coordinate them locally but also across these system levels.

The concept of local intelligence and decision-making will play a major role, given the increased level of available data, the number of actuators and capabilities for computing. From data and from offline simulations of the grid, we can learn what optimal decisions are and create decision making curves that are then used in online operation without the need for a coordinator.

As of now, however, most local schemes can be described as “one size fits all.” One example of this is how voltage control is applied to photovoltaic (PV) systems in Germany to keep the voltage within acceptable limits: by following standardized and predefined curves. Standards are valuable, but if the system becomes as diverse as we predict, we should consider standardizing how we determine the operational settings but not the actual decision curves. This is the only way to ensure that we make optimal use of all of the capabilities of the grid components.

Distributed optimization – in which communication allows for the coordination and exchange of information among “intelligent,” distributed resources – takes local intelligence a step further. In this case, the best actions of the individual components are usually found using an iterative approach, i.e. computational entities located at these resources talk to each other and based on the received information they update their own decisions until they have found an agreement. The concept of distributed optimization is relatively old, but it has quite recently gained new traction and importance in research on electric power systems as the infrastructure is becoming more distributed.

Despite the increasing importance of local intelligence, I believe that centralized decision-making will always have a role in the operation of the electric power grid. The system is mostly operated based on this principle now, and centralized operating schemes will certainly have their justification in the future. The electric power system is too complex and too important not to have some level of centralized monitoring and control. The question will rather be what decisions can be made locally and based on what data, who should be interacting with whom, and how such local decision-making should interact with a centralized entity.

When designing the operational structure of the future electric power system, we must take more than just technology into account. Electricity is being bought and sold in electricity markets, and the economic structure and rules of these markets have a major impact on the operation of the system. Furthermore, policies provide the framework within which the markets and operational procedures need to be designed.

Hence, we must take a holistic view that encompasses these different layers and considers the entire supply chain. That will only be possible if we carefully model and simulate these interdependencies – in the Nexus project1 we are working with researchers from other departments to develop a modelling platform capable of this – and use such comprehensive simulations to test and validate new operational approaches and market products. The key is to see the entire puzzle instead of only its pieces. And this is what we are working on.

Hyundai this week unveiled its upcoming long-range all-electric crossover at the New York International Auto Show. Since last fall it was known that the battery-powered version of its Kona small SUV would go on sale in late 2018. However, the Korean automaker in New York confirmed that it will carry a 64 kilowatt-hour battery pack capable of traveling about 250 miles on a single charge.

Hyundai did not indicate the Kona EV’s starting price, but the crossover EV is expected to sell for below $40,000—putting it in competition with the 238-mile Chevrolet Bolt and the base-level 220-mile version of the Tesla Model 3.

The Kona EV will initially only be sold in California, with further distribution to follow in the west coast and northeast states that adhere to California’s emissions rules. When an automaker says a vehicle is “coming in the fourth quarter,” it commonly means that the first keys will be handed over to a few customers in December—but legitimate availability will take a couple of more months.

The Kona is an attractive yet sedate crossover EV. It will become the only so-called affordable long-range electric sport utility on the market. The Kona EV will have a slight driving-range advantage over the Bolt and the base-level Model 3 (although the more expensive Model 3 being produced now has a bigger battery pack.) The Kona’s electric motor produces 201 horsepower, which matches the acceleration from the Chevy Bolt.

The EV version of the Kona has the same 19.2 cubic feet of rear cargo room as its gas-powered sibling. Its outward appearance is nearly identical, except for a somewhat odd hash-marked front fascia, which houses the charging inlet. Hyundai says the flush design improves aerodynamics. The narrow, split lighting units on the front fascia add a sleek design element.

Reviewers say the Kona platform offers a spacious front cabin, snug rear seating, and modest interior appointments. On the dash, a floating center-console push-button gear selector replaces the gas version’s conventional shifter.

Like other Hyundai models, the Kona is loaded with high-tech safety features such as forward-collision warning, automatic emergency braking, and lane-keeping assist. Unlike the gas version of the Kona, the all-electric model is not available with all-wheel-drive.

For the past year, Hyundai has been reporting sales of the Ioniq Electric hatchback, which provides 124 miles of driving on a single charge. However, the company has not yet registered selling more than 79 units in a single month. These anemic numbers raise the question of whether or not Hyundai will produce the Kona EV in sufficient quantities. Rumors suggest that annual production—at a global level—will be fewer than 30,000 units, indicating that availability will remain tight. “We’re still assessing volume,” Brian Smith, chief operating officer for Hyundai Motor America, told Ward’s Auto. “We’ll start small,” he said.

Adding the 250-mile Kona to the Hyundai showroom also casts some doubt on the long-term appeal of the smaller and lower-range 124-mile Ioniq Electric. Yet the plug-in hybrid version of the Ioniq could remain a viable choice, although it competes with the more compelling Kia Niro Plug-in Hybrid.

Despite the potentially low volume and a slow rollout, the introduction of the market’s third affordable 200-plus mile EV, especially in the form of a crossover SUV, is great news for electric-vehicle shoppers—and a sign of things to come.

The Tesla Model S was just rated the third-fastest accelerating production car in the world, beating out cars such as the Lamborghini Aventador and the Bugatti Veyron.

The head-snapping acceleration of the new supercharged Model S raises a question: Just how did engineers at Tesla get the electric, seven-seat family sedan to go so fast?

It turns out, one part of the car largely determines the Tesla’s impressive performance.

“They’re adding a bigger battery, and adding a bigger battery makes it more powerful,” said Mike Duoba, a mechanical engineer at Argonne National Laboratory in Illinois, who develops standards for hybrid plug-in vehicles.

Fastest ever

The Tesla Model S, used in what the company calls “Ludicrous mode,” can go from 0 to 60 mph (96 km/h) in 2.5 seconds, the company said in a statement. The only commercial cars on the planet that can beat the Tesla Model S, the LaFerrari and the Porsche 918 Spyder, each cost about $1 million and are “tiny” two-seater roadsters. Neither was built for the masses and neither is currently being produced. (The fastest custom-built race car, the Grimsel, can reach the same speed as the Tesla in about 1.5 seconds.)

Tesla confirms that the secret sauce behind this record-breaking time is the new battery. (Those who want to upgrade their existing Model S can purchase a bigger battery for $10,000.)

Better batteries

In general, a battery’s energy density predicts how much energy it can release (meaning how far the car drives) before recharging, while the power density (the energy density delivered per second) determines how fast energy can go in and out of the battery. That, in turn, governs how fast a car can accelerate, said Jordi Cabana, a chemist at the University of Illinois at Chicago, who studies battery chemistry.

The new Tesla battery helps quickly achieve these lightning-fast speeds by increasing the latter, Cabana said.

Though exact details haven’t been released, the Model S likely uses a lithium-ion battery where one layer, called the cathode, is made of a blend of nickel, manganese and cobalt oxide (NMC), Cabana said. When charged, lithium ions from the cathode are driven through an electrolyte solution into the anode, which is made of stacks of graphite. Lithium-ion batteries that overheat can sometimes produce a runaway chain reaction and catch fire; to prevent that, manufacturers encase individual cells containing both a cathode and anode in protective shells. The Tesla Model S battery likely has thousands of these cells, Cabana said.

The new battery may have crammed more cells into the same space of the older Tesla S battery pack, Cabana said.

“It looks like they changed the internal design of the battery pack,” Cabana told Live Science. “They reduced the amount of packaging that they put in the battery to make it safe.”

Historically, batteries that could produce enough power for fast acceleration or enough energy for long-range driving were typically quite expensive. That’s in part why battery-powered electric cars had a reputation for being less peppy than an equivalent gasoline car, Duoba said. However, a 2014 study in the journal Nature found that the cost of electric batteries has been plummeting, paving the way for cheaper, speedier, longer-range vehicles.

Built-in advantages

Take the battery out of the equation, and electric cars have an edge in speed tests.

For one, engines have myriad tiny parts that must spin, push, open and close to produce internal combustion at the right times, Duoba said.

“An engine is a sort of a breathing animal: It has to take air in and squeeze it,” Duoba told Live Science. “Those processes are not instantaneous.” (In a gas-powered engine, a piston compresses a mixture of air and fuel, causing combustion, which turns the motor.)

Electric motors, meanwhile, don’t have all those tiny moving parts.

“The electronics in an electric motor are almost instantaneous,” Duoba said. “There’s no delay in power, no waiting for throttles to close. All those little effects add up.”

Torque mismatch

Electric motors can achieve their maximum torque, or the rotational force that is transmitted from the motor to turn the wheels, anywhere from 0 to 4,000 revolutions per minute (rpm), which roughly corresponds to vehicle speeds between 0 and 30 mph (48 km/h), said Paul Chambon, a controls engineer who is an expert on powertrains at Oak Ridge National Laboratory in Tennessee.

In contrast, gasoline-powered cars cannot achieve peak torque at either a very low or very high rpm. Engines are optimized to run best with certain combinations of air flow, temperature and rotational speed. That means the torque in gas-powered engines peaks around 4,500 rpm, and that a graph of torque versus rpm looks like a domed hat, Chambon said.

So at zero speed, gas-powered engines are not at their peak.

“They don’t have that peak torque right away, you have to accelerate to middle speed to gain enough torque,” Chambon said.

Shifting gears

The dome-shaped torque graph also has another implication: At low speeds, the torque needed to propel the car doesn’t match the torque produced by the engine.

As a result, manufacturers place a gearbox between the engine and the wheels, which matches engine speed to that needed to rotate the wheels at a certain torque, Chambon said. Gear shifting creates lulls in the car’s acceleration.

But because electric vehicles can operate at peak torque anywhere from 0 to 4,000 rpm and can spin faster than engines, they often have no gearbox.

“There’s no gear shifting, that alone is probably worth half a second or maybe a third of a second,” in the 0-to-60 test, Duoba said.

As electric vehicle ownership continues to slowly grow, especially in cities and states such as California, which have invested in promoting these new transportation options, proponents continue to come up against the challenge of awareness and infrastructure. Despite a big increase in sales in 2017, a 25 percent year-over-year jump from 2016, total EV sales still amounted to just less than 200,000 total vehicles, less than 1 percent of the 17 million vehicles sold across the country last year.

How can consumers be convinced to make the switch, and how can those promoting EVs make the case that they offer a sustainable, affordable, and convenient ride?

A new campaign launched today at the New York International Auto Show hopes to answer some of those lingering questions by tapping into the power of a broad coalition of partners. A joint effort by automakers, states in the northeast, and local utilities, the “Drive Change. Drive Electric.’ campaign wants to encourage consumer awareness, improve infrastructure, and increase the number of electric vehicles on the road.

There’s plenty of self-interest involved. Automakers, some of whom have invested heavily in electric technology, want to sell more cars, and utilities hope to gain additional revenue by pushing customers to charge autos at home (90 percent of EV charging takes place at home or at work).

But, beyond promoting the technology and hopefully selling cars, the alliance demonstrates how different players may need to come together to catalyze EV adoption. It could be a model for the type of policy tools, partners, and engagement initiatives that cities, many of which are pushing for lower emissions and cleaner air, might consider.

“There’s a lot of great innovative work happening around EVs, but it isn’t at the scale to drive adoption from early adopters to mainstream consumers,” says Elaine O’Grady, senior policy advisor for Northeast States for Coordinated Air Use Management (NESCAUM), a nonprofit helping coordinate the initiative. “Transforming our transportation system is going to be a multi-stakeholder effort. It’s not just on the states, or automakers, or utilities.”

The campaign will see seven state—New York, New Jersey, Connecticut, Massachusetts, New Hampshire, Rhode Island, and Vermont—work together to promote electric vehicles with 16 global automakers including Ford, General Motors, Honda, Hyundai, Kia, Mazda, Mercedes-Benz, Mitsubishi, Nissan, Subaru, Toyota, Volkswagen, and Volvo.

The consumer awareness push will include promotions, a social media push, and a website meant to provide information about purchasing incentives, fuel savings, and charging infrastructure. No figures for the total investment in the campaign have been released.

O’Grady says it’s important to work together to bring down barriers to ownerships. Utilities want to encourage home charging, and many have started offering incentives for charging stations and off-hours car charging, and states have money to invest in infrastructure, thanks to the Volkswagen settlement. Coordinating efforts can make the most impact.