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With around a quarter of the UK’s greenhouse gas emissions coming from transport and around 90% from road transport alone the case for EV is widely known. More than half of all new cars in the UK are bought by fleets and while company car emissions are continuing to fall (17% in the last five years according to a recent survey by ALD Automotive), the more widespread deployment of EV is essential if we are to meet the Government’s environmental targets.
With an improving range of new vehicles being introduced to the market, backed by financial incentives, the EV industry is finally starting to build momentum. Buyers can choose between pure electric, range extended hybrid and plug in hybrid, which all come under the ultra-low emission classification (less than 75g CO2 per kilometer). Which drivetrain technology is the most appropriate is very much dependent on how the vehicle is to be used and should be fully understood before investing in new fleet.
Range anxiety is both a key perception and operational challenge to be overcome, and especially so while charging infrastructure is still being rolled out. Pure electric vehicles can now typically travel up to around 70-80 miles but this can vary significantly depending on ambient temperature, driving style and use of ancillary systems. If a user wants to drive the vehicle further than its range each day, then there are obvious limitations from the time taken to recharge.
For both pure electric and hybrid vehicles, less maintenance and a longer vehicle life should be expected with fewer moving parts and no oil changes required – this is, however, still a technology in its infancy and specialist warranty cover must be put in place. The vehicle’s battery is the most expensive part to be replaced and for pure electric this is currently likely to be required in 7-10 years.
Converting the Chance
While it is increasingly acknowledged that the whole lifetime costs of EV will be less than petrol and diesel, the compromise between battery size and vehicle range remains a challenge for OEMs and a key concern for users. There is, however, plenty of scope for innovative electronics to make a long lasting impact and the retrofit/conversion to hybrid electric drive in specialist vehicles can bring significant advantages, especially where electrical power take off is required for other uses, eliminating the need for an additional generator.
We have developed our own electric vehicle range extender which allows vehicles to drive purely on electricity until they get low on charge and then generate the electricity on-board to allow you to get to your destination and re-charge. The conversion of existing vehicles and modification to new ‘off the shelf’ cars, vans and trucks for a specific commercial application is more cost effective the larger the numbers involved. This typically becomes a more realistic option when there are more than ten vehicles as engineering design costs can be spread out across a fleet.
Battery cell technology is still improving and the commonly used lithium-ion chemistries cells now achieve up to 200 Watt hours per kilogram (Whr/kg). The automotive industry has a target to double this capability within five years, but even so, these batteries will still only offer around one thirtieth of the energy density of petrol or diesel fuel, and this will continue to be restrictive.
Not to be confused with parallel hybrids, range extended electric vehicles are designed to be run from the battery, but have a petrol or diesel generator to recharge as required. Electrical drive backed up by conventional liquid fuel reduces battery size and recharging times.
Hyperdrive Innovation has proven its range extended electric systems in modified petrol and diesel internal combustion engines, and these are now being deployed in new vehicles. The generator runs at its most efficient operating point and is turned off when it’s not needed, for example while sitting in traffic or when the battery charge reaches its upper threshold.
Whether specifying new vehicles, making modifications to existing fleet or looking at ways to improve vehicle management, data telemetry systems have an important role to play in monitoring vehicle states of health. Hyperdrive has developed a plug-in system which tracks state of charge of the battery pack, charge rates when the vehicle is plugged in, battery temperatures and any fault codes from any system on the vehicle.
Modern EVs are complex machines and for fleet managers to have instant access to accurate and uninterrupted data means that analysis can be carried out to optimise these sophisticated control systems, monitor any deterioration of fuel cells and to identify development issues with them as quickly as possible.
While developed for EV this system can equally be applied to petrol and diesel vehicles with information accessed remotely on the vehicle CAN system. The vehicle location is also identified using the device’s on-board GPRS and this means that the location, fuel range, fuel consumption rates, route efficiency and so forth can be continually assessed. Given that fuel and maintenance represent significant operating costs for large fleet operators, this information can also help yield significant savings to funding the transition to cleaner technologies.
Stephen Irish, Managing Director
Stephen has worked in tier one automotive supply chain companies, OEMs and engineering consultancies. He wrote his degree thesis on electric and hybrid vehicle technology almost 20 years ago and is a founding director of Hyperdrive Innovation.