Why Mild and Micro Hybrids Could be The Key to Cutting Car Pollution Without Compromises
The ADEPT (advanced diesel-electric powertrain) project car. (Image: Ricardo)
On September 14, 2016 at the LCV2016 Low Carbon Vehicle event in the UK, the ADEPT project car - an adapted 1.5-liter diesel engine Ford Focus - took to public roads for the first time and thanks to its ‘intelligent electrification' mild hybrid system did so using 10% less fuel than a normal Focus.
Hybrid technology - where a battery-powered electric motor steps in for the fossil-fuel engine from time to time to cut fuel use - is nothing new. Hybrid tech has been around for 115 years. What makes the system in the advanced diesel-electric powertrain (ADEPT) car game-changing is that it can cut fuel use and CO2 without big financial costs and could be applied to an existing gasoline or diesel engine.
A three-year research project led by UK-based Ricardo in partnership with Controlled Power Technologies (CPT) and the University of Nottingham among others, the ADEPT project uses a 48-volt hybrid system consisting of a lead-carbon battery and a SpeedStart system, built by CPT in place of the starter motor and alternator.
"SpeedStart can near instantaneously boost engine power and torque whenever required without having to feed additional fuel into the engine," said CPT chief executive Nick Pascoe. Instead battery power is routed to the engine via a drive belt. This cuts fuel use and therefore emissions. But the system is also able to capture more of the energy generated through braking and via the heat in the exhaust system than a 12-volt hybrid system can.
A mild hybrid system such as this - the ADEPT car isn't the only project currently underway - puts serious strain on a battery as it is constantly depleting and recharging, a practice that can destroy a lithium ion cell. However, a high-tech take on the traditional lead battery fixes.
"Advanced lead-carbon batteries in 48V automotive applications are the most cost-efficient way of meeting stringent future CO2 emission targets," said the Advanced Lead Acid Battery Consortium's Alistair Davidson. Delphi, a company making a name for itself in autonomous car technology, is also developing a 48-Volt hybrid system and it believes that they could start appearing in road-going cars by the end of 2017.
"One out of every 10 cars sold globally in 2025 will be a 48-volt, mild hybrid," said Jeff Owens, Delphi's chief technology officer. Both Delphi and ADEPT are convinced that 48-Volt systems will be a hit because of affordability. "It is likely to enjoy mass-market appeal in the short to medium term, due to the fuel economy, performance and cost benefits that it brings," said Ricardo Innovations MD Thomas Gutwald.