Go hybrid to reduce CO2

With automotive battery capacity currently scarce, expensive and suffering supply problems, the deployment of this limited resource is critical to maximising CO2 reduction. And the most effective way to reduce global vehicle emissions for the foreseeable future is not full battery BEVs – but mass adoption of hybrid vehicles.

That's the conclusion from Emissions Analytics, independent specialist for the scientific measurement of real-world emissions.

With tardy consumer adoption of BEVs and slow infrastructure roll-out compounded by concerns around an economical supply of batteries, it is essential to find the fastest, most efficient way to reduce CO2 now.

'One of our biggest challenges is fleet turnover, with vehicles staying on the road typically for up to 12 years,' explained Nick Molden, CEO of Emissions Analytics. 'It means that refreshing the entire fleet is a very slow process. Given reservations about current BEVs, we require an alternative that will have a more immediate impact. Due to CO2's long life in the atmosphere, a small change now is far better than a large change in the future. We need to optimise the use of the industry's available battery capacity to facilitate a critical early reduction.'

Through extensive real-world testing of electrified vehicles, Emissions Analytics has found that hybrids, whether in gasoline or diesel form, offer the highest CO2 reduction per kWh across all electrified powertrains.

Using mild, full and plug-in hybrid real-world emissions test data, from both European and US vehicles, Emissions Analytics compared hybrids with their internal combustion engine equivalents. Using the company's standardised on-road cycle, it determined the average CO2 reduction from hybridisation was 23% for the EU and 34 per cent for the US, with an average of 30% across all pairings.

Emissions Analytics then calculated the distance-specific CO2 reduction per unit of battery size (capacity), in g/km/kWh, for mild, full, plug-in hybrids and BEVs. The results indicated that mild hybrids are the most efficient way to reduce CO2, given limited global battery capacity. With a reduction of 73.9g/km/kWh, the technology was a clear favourite, with full hybrids coming in second at 50.5g/km/kWh.

The EU's post-2021 CO2 reduction target for passenger cars is 37.5% by 2030. Emissions Analytics tests clearly shows that, even with current technology, widespread hybridisation would achieve over three-quarters of that target.

Given a decade of further advances and innovations, it is possible that the goal could be met without the need for BEVs at all. Beyond the 37.5% reduction target, more extensive electrification would be required to bring whole fleet emissions down.