Asks ECCI’s Jim Hart.
Low carbon technology – what’s next for the private car?
Any environmentalist worthy of the name would agree that we must reduce the impacts arising from personal private transport. Furthermore, in effect there is a collective legal obligation to do this, as the carbon emissions reduction targets set out in the Climate Change Acts in force in the UK cannot be met without emissions reductions from the transport sector, as well as from buildings, industry, etc.
With the UK’s vehicle fleet subject to the fluctuations of the global oil market, there is also a strategic argument for introducing more flexibility into the system.
Most environmentalists would also agree that technology has a role to play, to add to the benefits achievable through behaviour change and demand reduction. The big question, though, is which technology? Even if there is eventually only one winner, it is highly likely that several approaches will enjoy some commercial and environmental success in the long transition process.
At the moment, the main technological options for reducing carbon emissions from the private car are as follows:
- Carry on as now, but work on fuel efficiency
- Carry on as now, but use biofuels instead of petrol or diesel
- Recognise the limitations of the above two strategies, and switch to a radically different technology, drawing energy from a new infrastructure powered by electricity from a low carbon system.
The motor industry, under some pressure from regulators both in Europe and the USA has been chipping away at option 1 for some time now and should continue to do so, as it should be possible to carry many of the gains over into the other emissions reduction strategies. But there is no chance of efficiency gains alone delivering the emissions reductions we are looking for in the long term.
There is already a requirement to include a proportion of biofuel in road fuels in Europe. This has its own negative impacts – not least the displacement of agricultural food production by agricultural fuel production. This strategy is highly controversial as it stands, and will only get more so as and when the biofuel targets are ratcheted up. Of course, some highly sustainable biofuels can be produced from various waste streams for instance – and this should be encouraged – but this is unlikely to be in sufficient quantity to meet emissions reductions targets.
Battery Electric Vehicles and Fuel Cell Electric Vehicles
And so we come to vehicles which derive their energy from electrical generators. On one hand there are the Battery Electric Vehicles (BEVs) which draw their power directly from the electricity grid, and on the other we have Fuel Cell Electric Vehicles (FCVs) which consume hydrogen and, therefore grid electricity as this is required to produce the Hydrogen. At the time of writing, BEVs have no more than a toe-hold in the personal private transport market (better known examples include the Nissan Leaf), and FCVs are a bit behind that, with good demonstration models like the one featured in the news item, but not yet a realistic market presence.
Carbon emissions associated with the use of FCVs are related to the emissions arising from the hydrogen production process. So, as with BEVs, their role in the low carbon economy is dependent on the success of ongoing efforts to reduce carbon emissions from the electricity industry. Advocates for the hydrogen economy also point out the potential for hydrogen production facilities to smooth out fluctuations in electricity supply caused by the increasing involvement of renewables in the generation mix. BEVs also, potentially, will offer this advantage as the ‘Smart Grid’ is developed, which will enable plugged-in vehicles to draw power when it is at its cheapest and possibly even to feed electricity back into the grid during peaks in demand when electricity is at a premium. Both types of vehicle – BEVs and FCVs – offer the additional environmental advantage of zero or negligible emissions at source, which should result in improvements to air quality in urban areas.
BEVs and FCVs have a number of pros and cons relative to each other, summarised as follows:
BEVs have the edge in the following ways:
- They use a relatively simple and developed technology (albeit waiting on some improvements in battery technology)
- More efficient use of primary energy (so called ‘[oil] well to wheel’ efficiency)
- It is probably simpler and cheaper to develop a BEV charging infrastructure for much of the population than a hydrogen refuelling infrastructure. It is possible for a recharging infrastructure to emerge ‘piecemeal’ as BEV enthusiasts install charging points at homes and offices, but hydrogen is relatively expensive to store as – being quite a diffuse gas – it needs to be stored under considerable pressure. Securing private investment in hydrogen infrastructure will be challenging in the absence of a FCV fleet (and vice versa).
FCVs have the advantage that in theory they present the user with fewer changes, for instance:
- they can cover a good distance before refuelling (a few hundred miles, in comparison to the 100 miles or so typical of the current range of BEVs)
- they can be refuelled at a Hydrogen pump in a matter of minutes (in contrast to battery charging which typically takes hours, and also simpler than the battery change-over stations that which might be used along with a battery leasing model).
- Hybrid Possibilities
There are also various hybrid strategies available, which are likely to play a significant role in the medium term and at least until a dominant strategy emerges. The most well-known of these are the plug-in hybrid electric vehicles, which combine internal combustion engines and battery-operated electric motors in various configurations. But other possibilities exist – for instance using renewable electricity to produce liquid fuels (typically via Hydrogen) for use in conventional vehicle engines, potentially in mixtures including both biofuels and conventional fossil fuels.
In conclusion, it seems inevitable that eventually, the majority of private cars will be required to run on energy derived from a low carbon grid, but the jury will be deliberating for some time on which technology is best placed to deliver.