Logistics specialist STEF has been testing an experimental 16 tonne all-electric vehicle under actual operating conditions for Carrefour France.

Developed by Renault Trucks on a Midlum vehicle chassis in partnership with PVI and IFP Énergies nouvelle, the truck covered 16,000 km and delivered 600 t of goods. This electric vehicle recorded a drop of 86% in well-to-wheel (WtW) CO2 emissions compared with its equivalent equipped with an internal combustion engine.

The drop in WtW CO2 emissions was calculated on the basis of the French energy mix, which is 92 g of CO2 for the production of 1 kWh (source: International Energy Agency 2011).

If this figure is applied to the tonne carried, it represents only 2.3 kg of CO2 emitted per tonne. That’s seven times less than an equivalent diesel vehicle. When used under actual operating conditions, this vehicle demonstrated it consumed only 0.95 kWh per kilometer travelled. This is very little and all the more remarkable since that figure not only includes the energy needed for the vehicle’s propulsion, but also the power used for operating auxiliary equipment such as the cooling system for the refrigerated body or cab heating

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The battery-electric 16 t Renault Midlum features a 103 kW electric motor powered by 2lithium-ion battery packs with a total energy of 170 kWh (battery weight: 2 tonnes). Payload of the vehicle is 5.5 t. Another pleasant surprise coming from this real-life test was the vehicle’s capacity to convert its inertia into energy.

During deceleration phases, the propulsion motor becomes an electrical generator which recharges the batteries. 25% of the energy used by the vehicle comes from this generator. This is a very high figure and rather unusual for an electric vehicle. Here again it is able to make energy savings and it proves the driver had been able to drive it in the most appropriate manner.

The only technical problems reported were due to settings or bad electrical contacts, which were rapidly rectified.

The quiet running vehicle enabled access to a night-time delivery slot (from 5 AM to 7 AM), noted Nadège Doubinsky, vehicle technical director for STEF. However, he added,

The only point that needs improving is the vehicle’s operating range. 100 km [62 miles] is not enough for the length of rounds we do in the town center.

The test was conducted in two phases. The first was from June to December 2012, with the vehicle delivering fresh products to three Carrefour City stores in Lyon, with rounds of about 40 km (25 miles) a day. The second, from January 2013 to the end of December 2013, involved the vehicle delivering frozen products to six Carrefour Market shops in the Lyon area with rounds of some 90 km (56 miles) a day.

The length of the test made it possible to see how the vehicle performed under all weather conditions and in temperatures ranging from -8° to +32°C.