Seven big questions about electric vehicles

　　Economists at EIA do not expect CO2 reduction in transportation due to seven major problems with electric vehicles:

　　· Electric vehicles cost more than gasoline vehicles over the lifetime of the vehicle.

　　· Fast charging stations are at risk of losing money.

　　· Rare earth materials risk becoming rarer and more expensive.

　　· Waiting for charging is sometimes inconvenient.

　　· Drivers sometimes feel anxious about range and charging.

　　· CO 2 is emitted when burning natural gas or coal to generate electricity.

　　· CO 2 is emitted when mining rare earth materials and manufacturing batteries.

　　The rest of this article discusses why standardized, replaceable batteries can help with all of these issues.

　　Replaceable batteries to the rescue?

　　Currently, the world has mechanical and electrical standards that define batteries, and these standards allow people to power many products at low cost.

　　Standardized battery example

　　Currently, proprietary batteries are built into electric vehicles and charged periodically. Alternatively, there could be a standard plug-in battery, where all cars use the same form factor, and replace it with a new one in less than a minute. Owners will pay for the electricity consumed and the wear and tear on the EV battery. When using less costly batteries, they hold less charge. Cavities will be dug out at key locations and put in mechanisms for charging, storage and switching. The car positions itself above mechanics and swap.

　　Those who drive less than 100 miles (160 kilometers) a day can swap in low-cost, low-range batteries and charge them overnight. Costs will decrease as lower-grade batteries use fewer rare-earth materials (for example, 20-kWh lithium iron phosphate [LFP] costs less than 60-kWh nickel-manganese-cobalt [NMC], and costs will decrease). During longer trips, one can replace expensive high-end batteries or replace batteries more frequently. Swapping also reduces costs through commoditization, as multiple battery manufacturers will compete and drive down prices.

　　Families can install swap rooms in their driveways that contain swappable batteries. These can be charged by solar during the day, power the house at night, and swap with the car as needed, as shown in the photo below.

　　Electric vehicle batteries in residential exchange rooms power homes at night.

　　Swappable batteries are not a new idea. For a video of David Borlace's discussion, click here. See "Replaceable Batteries" in How to Decarbonize Transport for more details.

　　exchangeable disadvantages

　　Swapping might sound great. However, it also has a dark side:

　　· Replacing batteries requires a huge effort by automakers, who design vehicles around swappable batteries and build new factories to produce them.

　　· The world will need to install many underground exchange rooms at enormous cost.

　　· Exchange must fight "chicken versus egg". Automakers may not be willing to participate without many swap rooms, and swap companies may not be willing to participate without many swapping cars. To move forward, swap chambers will likely initially be placed at car dealerships, where drivers go to get expensive, long-range, fast-charging batteries before taking long trips. Otherwise, they may rely on low-cost, short-range, slow-charging batteries that charge at home.

　　Little money next step?

　　As a next step, governments or foundations could spend tens of millions of dollars to design and prototype standardized swappable battery systems to better understand technical and economic feasibility.

　　Cut battery costs by four times with less range, slower fast charging

　　Electric vehicles typically offer 300 miles of range and fast charging in 30 minutes. However, if the range requirement is reduced by two times and the fast charging speed is reduced by four times (for example, the minimum charging time is two hours), then the cost associated with the battery may be reduced by more than four times.

　　· Traditional 300-mile range batteries use NMC chemistry. Alternatively, LFPs cost approximately 3 times less due to a 30% lower cost per kWh and twice the lifetime (3 = 2 ÷ [1 – 30%]). The downside of the LFP is that it offers less range for the same size and weight (eg, 150 miles for the LFP vs. 300 miles for the NMC).

　　· Slower fast charging generates less heat, which reduces the cost of thermal management systems within the battery.

　　· Slower fast charging extends battery life, reducing costs.

　　· Slower fast charging requires lower cost charging equipment. For example, an AC-DC converter that charges in 8 hours costs about 6 times as much as a converter that charges in 1 hour.

　　· Slower fast charging requires less utility service (eg, 40 kW service costs less than 160 kW service).

　　We will now explore why a standardized replaceable battery might help solve the seven EV problems described earlier.