A lot has been written on the subject of extending the range of Electric Vehicles. Battery technologies are becoming more energy dense and able to charge faster; electric motors and powertrain technologies are becoming more efficient. While these improvements will go some way towards addressing the distance challenge, consumers are still waiting to see a broader consensus and gain confidence in a longer-term approach. No one wants to buy an EV with a limited range that could potentially leave them stranded. While Hybrid Vehicles offer an ‘acceptable-for-some’ compromise for now, they are more expensive to manufacture and tax, and continue to pollute the environment.
One of the solutions to address this distance challenge has been proposed many times over the years. It involves embedding an inductive charging loop in the road, so that EVs can receive additional power while moving. Inductive charging is not new, and recent technology innovations have shown how efficiencies have been driven up to nearly 90% using high frequency systems in ideal test conditions. However, there are some fundamental challenges that proponents of these in-road schemes tend to gloss over:
- Putting the infrastructure in is going to cost $$$s. It’s not just what goes into the roads, but all of the supporting electrical distribution infrastructure required to supply large amounts of power to the roadside from national grid systems. EVs need substantially more power than existing signage and overhead gantry systems, and there is a school of thought that this approach simply isn’t economically viable.
- Whatever is put in will then need ripping up and replacing. As various competing technologies evolve, it is likely that different induction systems would be required in the road, and investors won’t want to over-invest in one solution which they know will require replacement.
- Disruption to highways and people using them will be enormous. Even if a “track-laying” type machine is built that can process one lane at a time continuously, it still needs to connect the induction assets to roadside power points that then connect to the local distribution grid. It will be a long and laborious process.
- There will always be significant energy wastage. Induction transference (across the air) is lossy compared to a direct connection – and disparate vehicles will interact with this system in different ways with different degrees of efficiency.
So what are the alternatives?
One option is for a driver who has a large store of energy in their EV being able to trade that with someone else whose battery is almost empty, by using a transfer cable when stationary. With fully autonomous vehicles there’s no reason why a fully charged vehicle couldn’t partially recharge an almost empty one “mid-flight” while both are moving at the same speed, either through a cable connection (similar to how airborne tankers refuel military aircraft) or via induction transfer between vehicles. There may prove to be a strong economic case for large battery trucks driving around able to charge other EVs. There is already an EV “Platoon” concept for several trucks all travelling in convoy that could be extended to provide this sort of capability: a fully peer-to-peer energy charging network “on-wheels”. A gig-economy proposition could evolve around the provision of mobile energy supply.
Many senior decision makers are still blinkered by their big infrastructure way of thinking – and frequently dependent on it for incremental revenue – which is one reason why novel concepts like P2P energy sharing for EVs are often ignored by policy makers (and subsequently in the media).
Another option is swap-out batteries. While it’s too unwieldy to swap out the main battery (as the car is often built around it), an EV could also have a modular swap-out battery that perhaps can store an additional 10-15% of main EV battery capacity. This battery could be swapped out very quickly – as it would be compact and designed for speedy exchange. This could be done at roadside drive-by swap-out stations, or in dire circumstances by top-up trucks similar to those suggested above but which physically exchange modular battery packs while on the move. There is precedent: we are all familiar with exchangeable gas bottles or cylinders for cooking and heating; or laptop computers that have two batteries, one built in and one that can be swapped for a freshly charged battery. At one point even Tesla was enthusiastic about swappable batteries, but is now focused its Supercharger platform.
Both of these options (P2P energy trading, or swap-out batteries) could deliver regular range extensions on long journeys:
- For the first, it is likely that a P2P model will become established in the domestic electricity Smart Grids of the future. Extending this concept to the EV network would be a natural evolution, with the P2P components of future Smart Grid control systems being adapted to manage the overall process of P2P EV charging and payments with optimal efficiency. In a future Smart Grid world the best place to charge an EV may actually be at home, from locally sourced energy stored in a Home Battery. Reliable access to other established charging sources further afield may be limited by the economics of cost and unpredictable demand by location, which is why a P2P sharing/trading model, when away from home, might work well.
- For the second approach, having the ability to exchange swap-out batteries would also enable vehicle owners to store a “spare” in the boot/trunk, similar to the 5 litre/1 gallon fuel can that many people rely on in case of running very low on fuel. If smart battery providers and car manufacturers can agree on some standard capacities and form-factors, this would allow an “energy pack” to have multiple uses, in the car, at home, or wherever else an amount of electrical energy is required. Agreeing on standards to this degree has always proved a significant challenge in the automotive sector where competition precludes commonality, and the current range of different shapes and sizes for 12V car batteries is a discouraging example for this model.
In order to consider which approach makes most sense, we need to step back from the big infrastructure perspective and instead look at how approaches like peer-to-peer have disrupted other industries. While the swap-out battery approach might make sense to consumers, in the absence of sufficient collaboration between manufacturers the more user-centric P2P approach may prevail.
At Ness we are always learning from the latest thinking and best practices from other industries and bringing this to bear on a client’s sector, helping them to plan their operational platforms for the future.