When Is It OK To Trade Energy Out Of Your Electric Car?
The energy supply for electric vehicles has always been a matter of public debate, but the current debate about when to trade it out of a vehicle has focused more on its efficiency and safety features.
That’s the topic of a new report from energy efficiency consulting firm EcoLogic that compares the efficiency of the two main types of energy storage, battery storage and battery-powered electric vehicles (BEVs).
The study, published in the journal Energy Economics and presented at the European Electric Vehicle Manufacturers’ Association conference in Paris, found that electric cars that use BEVs have lower fuel consumption, better efficiency, and are less likely to exceed their expected energy density.
That translates to more efficiency in driving, less CO2 emissions, and less overall vehicle wear and tear.
In addition, the report notes that BEVs can be more efficient than conventional batteries when it comes to storing electricity and, thus, a more efficient way to get energy from the grid.
The authors also found that BEV batteries are significantly more energy dense than those used in conventional cars.
These advantages make BEVs an attractive option for electric vehicle owners and their fleets of electric vehicles, but they also require the addition of an additional component: the battery itself.
The report recommends that electric vehicles use a combination of two types of battery: lithium-ion (Li-ion) batteries that have a higher capacity and a smaller battery capacity than a conventional battery, and lithium-air (Li/Al) batteries with a higher energy density than a traditional battery.
Both of these batteries are already used in electric vehicles and could be adopted as part of a future electric vehicle fleet.
“Electric vehicles will always be subject to environmental regulations,” said Jonathan Bloch, a research associate in EcoLogics’ energy efficiency research group.
“But for the foreseeable future, we should expect that electric vehicle batteries will become a more viable and affordable option in terms of energy density.”
A battery with a smaller capacity can be used for smaller vehicles, which tend to be larger than conventional vehicles.
“If we think about the overall energy footprint of the vehicle, a larger battery could be more energy efficient than a smaller one,” Bloch said.
This means that a larger capacity battery could potentially provide more battery capacity and thus an improved energy density of the energy delivered to the vehicle.
Bloch notes that there are a variety of other energy storage options in the market today, including lithium-manganese batteries, which can store energy up to 10 times more energy than conventional lithium-hydroxide batteries, and batteries made of copper.
However, the EcoLogical report notes, it will take years to develop a better battery with more energy density and a larger, safer capacity.
The study also looked at how much electricity could be saved using each battery type, and how much fuel would be saved when using all three types of batteries in a vehicle.
The battery that has the highest efficiency is the Li-ion battery, which has a capacity of up to 300 kilowatt hours, or about 40,000 pounds of energy, according to Bloch.
That capacity is greater than most electric vehicles today.
In contrast, the Li/Al battery has a much smaller capacity of around 100 kilowatts, or 15,000-20,000 gallons of energy.
This difference is due to a difference in the energy density between the two types.
“With the increase in energy density, the capacity of Li-air batteries can also be reduced,” Bluch said.
“It becomes important to make sure the energy capacity of the battery is lower, so it’s not a constant energy density as with a conventional lithium ion battery.”
As with the other battery types, there are drawbacks to using the Li–Al battery.
The researchers note that the energy storage in these batteries is not completely free from degradation, especially if it comes into contact with the environment.
“Li–air batteries have a tendency to degrade under high temperatures and conditions, especially at high voltages and in the presence of low humidity,” Blich said.
The team also noted that it’s important to keep the energy of the batteries in check.
“When using the battery, the electric motor should be turned off and the car should not be driving, so the batteries should not get too hot or the electric motors should not run hot,” Bloc said.
A battery that is in the process of being upgraded to a Li–air battery has the same energy density but can also use a different type of battery, such as a lithium-polymer battery.
However of course, this is not a fixed situation.
“In the future, batteries could be upgraded to include a higher-capacity Li–polymer-based battery that can be recharged with more battery power,” Blomich said, noting that the cost of upgrading batteries to a new battery is also a potential issue.