A company called Better Place out of California thinks it has a good alternative to plug-in hybrids or traditional all-electric vehicles. Rather than having to always plug in a vehicle to charge the battery, the company will set up a series of "refueling" stations whereby the battery can be swapped out and replaced with a fully-charged battery in the same amount of time it takes to fill up on gas. The batteries will be mounted underneath the vehicle using the same type of hooks used to hold bombs onto military aircraft and a robot will be able to swap batteries in about 45 seconds at these Better Place battery stations. It's an interesting premise that has managed to get significant funding, $300 million worth, as well as Renault-Nissan to agree to produce vehicles that use a battery system compatible with Better Place's robots.
If a large enough customer base were established it could conceivably be cheaper than plug-in hybrids or all-electric vehicles as it would avoid the expense of having the internal combustion engine and associated hardware while possibly requiring less batteries than standard all-electric vehicles, if customers are willing to accept less electric range with battery swap capability.
Alternatively, if battery prices are too expensive, then plug-in hybrid vehicles would be more economical and if battery prices are too inexpensive (a smaller risk), then electric vehicles with non-swappable batteries with longer electric ranges may be more cost effective. In the end it will come down to a combination of customer utility and cents per mile.
One of the challenges would seem to be the chicken and the egg problem that plagues any type of new fueling infrastructure whether it be hydrogen or battery swapping robot stations. For the system to be economical it seems that a large number battery swap stations would need to be in place and a large number of customers paying to use these stations. To minimize this issue, Better Place is starting off in smaller countries such as Denmark and Israel, which require a smaller number of stations. Customers do also have the option to charge at home.
Another factor potentially impacting the long term commercial viability of this system is energy storage technology. If breakthroughs in ultra-capacitors or high rate capability batteries allow for electric vehicles that can be charged in minutes instead of hours then using a robot to change the battery becomes unnecessary. Although this type of technology may be available in the lab, it is likely a ways away from making it onto vehicles and so is probably not a near-term threat to their business model.
A more pressing question is whether customers will spend tens of thousands of dollars on a vehicle from a start-up company that at any point could go bankrupt, leaving them with a vehicle and no robot swapping stations in which to change their battery.
Thompson, Clive "Batteries Not Included" NY Times, 16 April 2009.
Better Place http://www.betterplace.com/
LaMonica, Martin "Q&A: Better Place's Electric Car Plan, Brilliant or Nuts?" CNET 24 April 2009 http://www.cnet.com.au/q-a-better-place-s-electric-car-plans-brilliant-or-nuts-339296126.htm