BASIC KNOWLEDGE - ELECTRIC CARS TYPES The 5 different electric cars types explained
As OEMs solidify their commitment to reduce their carbon footprint, their focus is on electric cars which reduce carbon emissions, cut oil use, and provide an improved driving experience. Alongside vehicle development is significant advancements in battery R&D, vehicle-to-grid connectivity, and wireless charging.
The last few years have seen carmakers build electric vehicle (EV) adoption into their plans to increase fuel efficiency and achieve net-zero carbon emissions by 2050. GM has made a commitment to 30 new global electric vehicles by 2025 and plans 19 different battery and drive unit configurations initially, including horizontal and vertical stacks, to power vehicles ranging from affordable cars and crossovers to luxury SUVs and pickup trucks. The company is also intent on creating an electric car able to run up to 450 miles on a full charge. Kia aims to have battery electric vehicles, plug-in hybrid and hybrid electric vehicles make up 40 % of Kia’s total sales by 2030. 11 new Battery Electric Vehicle models are planned for release by 2026.
Volkswagen aims to reduce the carbon footprint of cars and light-commercial vehicles across the entire value chain by 30 % by 2025 compared to 2015 – and by 2050 to make the entire Group’s balance sheet CO2 neutral. Daimler this week announced an acceleration of their efforts in electric vehicle development with Ola Kallenius, chairman of the board of management of Daimler and Mercedes-Benz, stating “Almost two years ago, we presented our Ambition2039. We want a CO2-neutral fleet of new cars. It’s our goal to reach this target sooner.” In 2019, Daimler said it expected plug-in hybrids or all-electric vehicles to make up more than 50 % of its car sales by 2030.
But to understand the various electric cars OEMs are rolling out, each with their own distinct operating systems, it is helpful to first understand the different kinds of electric vehicles:
Battery electric vehicles (All-electric cars)
Battery electric vehicles (BEVs), also known as all-electric vehicles or pure electric vehicles are powered entirely by electricity. They are built without a petrol engine, fuel tank, or exhaust pipe.
Battery electric cars are powering by plugging into a public or at home charge point and accessing energy from the grid. An Inverter converts the electric current in the form of Direct Current (DC) into Alternating Current (AC) The electricity is stored in rechargeable batteries. These batteries power the electric motor (instead of an internal combustion engine). The single-speed transmission sends power from the motor to rotate the wheels. All-electric vehicles can also charge their batteries internally using Regenerative Braking. When the brakes are pressed or the car decelerates, the motor becomes an alternator, producing power, which is sent back to the battery, therefore using kinesthetic and heat energy that cars typically waste. This generated electricity is stored for future use in the batteries.
BEV batteries are lithium-based with a low rate of discharge, meaning the charge remains even when the car isn’t driven for weeks. As they operate solely on battery power, they tend to contain large battery packs and take a while to fully charge.
There is a variety of charging methods:
- Charging at home using a standard 120 V wall outlet: An hour of charging typically generates enough battery power for a distance of 2-5 miles.
- EVSE (Electric Vehicle Standard Equipment)- This equipment operates on a 220/240 V circuit and can be done at home with the appropriate installation or at an electric vehicle service station. An hour charge generates a cover of approximately 10-25 miles.
- DC Fast charger: These 480Vchargers can charge up to 80 % of the full charge in less than one hour at a DC fast charging station.
Battery electric vehicles typically cover a range of distances on a full change, dependent on the battery size (kWh). Batteries with higher kWh, facilitate further travel. For example, Volkswagen’s upcoming ID.4 has an estimated range of 250 miles while their earlier 2019 e-Golf had a range of 125 miles.
Examples of Battery Electric Vehicles in the market:
- Chevrolet Bolt
- Kia EV6
- Nissan LEAF
- Renault Zoe
- Tesla Model S
- Tesla X
- Toyota Rav4
- Volkswagen e-Golf
Hybrid electric vehicles
Developments in BEV design and technology help address the shorter-range capability of first-generation BEVs. An example is the development of Hybrid electric cars and vehicles. Hybrid electric vehicles (HEVs) are the second most popular type of electric vehicles.
HEVs use both electricity and petrol/diesel as their fuel source. They are equipped with both an electric motor and an internal combustion engine. The electric motor is uses at lower speeds where it provides higher torque (rotational force). As the speed increases, the vehicle utilizes the internal combustion engines to provide higher torques at higher speeds. This means that unlike pure electric vehicles you don’t have to plug them in to recharge their batteries. Hybrids also feature regenerative braking like Battery Electric Vehicles.
Examples of HEVs include:
- Ford Fusion Hybrid
- Honda Accord Hybrid
- Honda Civic Hybrid
- Hyundai Elantra Hybrid
- Kia Optima Hybrid
- Toyota Prius Hybrid
- 2010 Tesla Roadster
- 2010 Chevrolet Equinox
Plug-in hybrid electric vehicle
Like standard hybrid electric vehicles, Plug-in Hybrid Electric Vehicles (PHEVs) run on battery and petrol/diesel. Like the BEVs, the electric battery can be charged using an external charger, and it uses conventional fuels for its second motor in the same way as the Conventional Hybrids. Unlike Hybrid EVs, PHEVs can be plugged into an electric outlet to charge as opposed to being restricted to regenerative braking alone.
PHEVS have rechargeable battery packs that provide 20-80km (depending on model) of all-electric driving before a gasoline engine or generator turns on for longer trips. The battery's energy is recharged by the ICE, wheel motion, or by plugging into a charge point.
Plug-in Hybrid Electric Cars and Vehicles are able to drive longer distances than BEVs because they are able to operate using a gasoline engine or generator, meaning they are able to utilize gas station services. They however use roughly 30 % to 60 % less petroleum than conventional vehicles and are considered cheaper to operate and maintain compared to traditional petrol/diesel hybrids. But fuel savings need to be weighed up compared to other costs. The PHEV's fuel-saving capability means it uses a larger battery pack to provide those miles of electric-only driving before its internal-combustion engine kicks in to share the load. This plus the additional hardware and software required, results in a higher price than a standard hybrid. For example,a Prius plug-in hybrid, costs significantly more than a base level Prius.
Examples of plug-in hybrid electric vehicles include:
- Audi A3 E-Tron
- BMW X5 xDrive40e
- Chevy Volt
- Ford Fusion Energi
- Mercedes GLE550e
- Mini Cooper SE Countryman
- Mitsubishi Outlander PHEV
- Porsche Cayenne S E-Hybrid
- Prius Plug-In
- Toyota Prius Plug-In
- Volvo XC90 T8
- VW Golf GTE
- Volvo XC90 T8
Extended range electric vehicles
Extended Range Electric Vehicles (E-REVs) also known as Range Extender Electric Vehicles (REEV) are equipped with a small petrol or diesel powered generator to recharge the battery. The vehicles operate on electric power and switch to the conventional engine when more power or speed is needed, or the battery runs out of power. and allow extended range when the car battery level is low.
The range extending fuel enables the vehicles to gain the cost and environmental benefits of battery power, while also equipped with the full driving range from the extending fuel motor. They are however distinct from a Hybrid vehicle where the fossil-fuel motor only re-charges the battery and is not connected to the wheels. E-REV wheels are always driven by the electric motor island.
Extended Range Electric Vehicles produce low CO2 emissions due to their reliance on electric power, about 20 g/km which is lower than that of Hybrid Electric Vehicles. They can also cover large ranges.. Many range extender vehicles including the BMW i3, are able to charge their batteries from the grid as well as from the range extender, and therefore are a type of plug-in hybrid electric vehicle. The BMW i3 can travel up to 153 miles fully changed and up to 200 miles with the extended range.
Examples of extended range electric vehicles include:
- BMW i3
- BMW i8
- Chevrolet Volt (no longer in operation)
- Vauxhall Ampera (no longer in operation)
Hydrogen fuel cell electric vehicles (FCEV)
Hydrogen Fuel Cell Vehicles (HFCVs), also called Fuel Cell Vehicles, have a fuel cell stack that uses hydrogen to create the electricity needed to power the wheels of the vehicle. A fuel cell is a device that generates electrical power through a chemical reaction by converting a fuel (hydrogen) into electricity. Although you refuel them with hydrogen, HFCVs are actually powered by an electric motor. The hydrogen in the fuel tanks travels to the fuel-cell stack. Inside the stack. The hydrogen undergoes an electrochemical reaction with oxygen that’s collected through the air intake. This process generates electricity which either directly powers the motor or is stored in the battery for future use. The HFC is able to generate power for as long as there is a steady supply of hydrogen.
Hydrogen Fuel Cell Electric Vehicles can be refilled with hydrogen at refilling stations. Refilling takes about 3-5 minutes and the vehicles have a range of 300 miles between refillings. This means on a full refill, HFCVs can cover a much higher range than a fully charged Battery Electric Vehicle.
In efforts to move from fuel to zero-emission vehicles and fleets, there are still several factors that prohibit consumer adoption. HFCVs are highly regarded from an emissions perspective even though their use is still in development. There are however a number of challenges before they go mainstream.The purchase price of FCEVs is high. Public hydrogen refuelling stations are limited. Also, extracting hydrogen from a water molecule is an energy-intensive process that generates greenhouse gas emissions if renewable energies are not used. These include vehicle cost, range, charge time, battery life uncertainty, vehicle model choices, charging infrastructure, and understanding of the technology. While hydrogen fuel cells and hybrid HFC/electric offerings won't be mainstream anytime soon, they create an opportunity to progress innovation future and expand the existing suite of products in development and at market.
Hydrogen fuel cells are being rolled out across a number of transport verticals including trains, trucks, and buses. Last year saw a multi-million dollar project integrating hydrogen technology into 50 trucks, marking the first such green fleet in operation in the world. Each of the Hyundai Xcient Fuel-Cell trucks features a 190 kilowatt fuel cell comprised of seven high-pressure tanks holding around 35kg of hydrogen. This provides a long distance range of about 400km before refueling is required, which far surpasses the capabilities of vehicles powered by electric batteries. Hydrogen fuel cells can generate more power when pulling heavier loads uphill than an equivalent sized battery, and offer a greater range.Hyundai is investing heavily in hydrogen, planning to put 1,600 hydrogen trucks on Swiss roads by 2025 and set to launch similar projects in other European countries as well. Their use is expected to be widespread over the next decade.
Examples of hydrogen fuel cell electric vehicles:
- BMW i Hydrogen NEXT
- Honda FCX Clarity
- Hyundai Nexo
- Mercedes Benz F-Cell
- Hyundai ix35 FCEV
- Riversimple Rasa
- Toyota Mirai
What’s next for powering vehicles?
The initial expense of electric vehicles and the inconvenience of charging has proved a challenge to consumer adoption, even as OEMs transition to electric vehicle stock and subsidies and rebates exist in many countries to promote electric vehicle adoption.
However, significant R&D is being put into battery technology. In California, a company called QuantumScape is at work on the next generation of battery technology: solid-state batteries with lithium-metal anodes. QuantumScape’s proprietary solid-state separator replaces the organic separator used in conventional cells, enabling the elimination of the carbon or carbon/silicon anode and the realization of an “anode-less” architecture, with zero excess lithium. In such an architecture, an anode of pure metallic lithium is formed in situ when the finished cell is charged, rather than when the cell is produced. Unlike conventional lithium-ion batteries or some other solid-state designs, this architecture delivers high energy density while enabling lower material costs and simplified manufacturing.
Because it eliminates the side reaction between the liquid electrolyte and the carbon in the anode of conventional lithium-ion cells, QuantumScape’s battery technology is designed to last hundreds of thousands of miles of driving. QuantumScape’s battery technology is capable of running for over 800 cycles with greater than 80% capacity retention. The company suggests this would translate to potentially a 50-80 % improvement in battery power vs today’s leading electric vehicles, depending on the vehicle design. Thus, for example, a vehicle that gets 200 miles of range could get between 300 and 400 miles of range. The company has over 700million in funding including investment from Volkswagen.
Vehicle-to-everything charging electric vehicles
Last month Hyundai launched the Ioniq 5 during a virtual event in Seoul. Along with the choice of a 58 kWh or 72.6kWh battery, it comes with an optional solar roof, a complimentary charging source that can help extend the range, and is enough to charge the internal 12V battery.
Hyundai shared that the solar panels can add up to 2,000km (1200 miles per year) or around 5-6km per day if driven in sunny environments.
The Ioniq 5 can be used to charge electric devices including electric bikes, household appliances, and mobile phones via either the charging port or a 240-volt plug installed under the back seat. It also comes with the capacity to (slowly at just 3.6kWh) charge other electric vehicles providing it has a minimum of 15 % charge left in its own battery - useful in an emergency situation.
Electric vehicle to grid charging
KIA is also focused on the car’s charging system. The Kia EV6y is equipped with an Integrated Charging Control Unit (ICCU). The ICCU enables a new vehicle-to-load (V2L) function, which is capable of discharging energy from the vehicle battery. The V2L function is capable, as an example, of operating a 55-inch television and air conditioner simultaneously for more than 24 hours. Kia markets camping as one of its use cases. The system is also able to charge another EV if needed.
One of the most interesting capabilities of the Ioniq 5 is that it can not only power electric devices and other vehicles but that it will come equipped with vehicle-to-grid (V2G) charging capabilities. V2G is when a bidirectional EV charger is used to supply electricity from an EV car’s battery to the grid via a DC to AC converter system usually embedded in the EV charger.
In 2016, Researchers at Delft University of Technology (TU Delft) in the Netherlands successfully engineered and installed a socket on a Hyundai ix35 Fuel Cell that serves as an electrical outlet. It’s based on the idea that car owners use their vehicles for transportation only 5 % of the time. Unlike a fossil fuel-powered car, a fuel cell vehicle when parked can produce electricity from hydrogen; cleaner and more efficiently than the current electricity system and with useful ‘waste’ products heat and fresh water. The converted Hyundai ix35 Fuel Cell has a capacity of ten kilowatts, sufficient to power on average ten homes.
Nissan is also working in this area, collaborating with energy companies on pilot programs globally to create Virtual Power Plants with Nissan LEAFs and e-NV200s.
Nissan EVs can provide electricity to households through the Power Control System. The power supply system* lets a Nissan EV share the electricity stored in its high-capacity lithium-ion batteries with an ordinary home once the car is connected to the home's electricity distribution panel via its quick-charging port. In this way EV batteries can provide additional value.
It will be interesting to see where innovation goes in this area, as it points to a future of vehicle to grid energy where electric vehicles not only can support household power but also provide energy to the grid in critical situations.
Electric vehicles and wireless charging
As global automakers race to support both consumer and government-generated demand for zero-emissions vehicles, they are also developing wireless charging capabilities that will improve the owner experience. One of the top “wish list” items for potential EV and PHEV consumers is being able to drive into a garage or parking space and have your EV charge automatically, without plugging in. MIT spinout WiTricity develops solutions to enable wireless power transfer over distance using its patented magnetic resonance technology. This is achieved through resonant coupling, a process that occurs when the natural frequencies of the two systems – a source and a receiver — are approximately the same. WiTricity power sources and receiver devices are specially designed magnetic resonators that efficiently transfer power over large distances via the magnetic near-field.
The company envisions a not-too-distant future when dynamic charging will support moving vehicles (from taxi queues to roadways), and autonomous vehicles and robots will charge without human intervention. WiTricity works with top global carmakers and Tier 1 suppliers to deploy magnetic resonance solutions, helping realize a future of transportation that is electrified.