“New ZOE, an energy efficiency champion”

Published by on 09.13.2019 - 3 min

With up to 395 km of range on the WLTP*, New ZOE offers one of the best ratios on the market for battery capacity to distance covered. Éric Blanchard, Director of Electric Vehicle Motors and Batteries at Renault, explains what’s at work making this record energy efficiency possible.

Why is the energy efficiency of an electric car so important ?

Energy efficiency lets you know how many kilometres you will be able to travel with a given amount of energy. In ZOE’s case, it shows that the entire car has been optimised to improve performance and limit energy loss. Increasing the lithium-ion battery’s overall capacity can only be accomplished in small increments, due to the impact on weight, size and production cost. Working on improving efficiency is therefore crucial to providing a high range while still keeping the vehicle affordable.

How does New ZOE attain this level of efficiency ?

New ZOE is carrying a 52 kWh battery that provides up to 395 km as measured by the WLTP test cycle. The ratio between the battery capacity and the vehicle’s range is thus almost unmatched on the electric car market. One of our design masterstrokes, compared to the previous generation, has been the creation of a battery that has a larger capacity but does not significantly impact the vehicle’s energy efficiency. The Z.E. 50 battery is the exact same size as the Z.E. 40, and its weight has only gone up by 20 kg, in exchange for an 11 kWh total increase in capacity. We could have made a car with an even more powerful battery, but doing so would have upset the balance between performance, range and affordability that we strive to maintain.

Éric Blanchard, Director of Electric Vehicle Motors and Batteries at Renault

How does the question of efficiency fit into the design of a car like the ZOE ?

This issue is constantly being considered at every step in the creation of our electric vehicles, from the design stage to the optimisation of our industrial manufacturing processes. New ZOE’s front bumper, for example, has two lateral vents that ensure air flows smoothly along the sides of the car, contributing to its aerodynamic quality. The Cléon plant, where New ZOE’s motor is made, is constantly improving its machining methods. For New ZOE, it focused, among other things, on the reducer, the mechanical part that uses the revolutions of the motor to make the wheels turn. These optimisations made it possible for that component to handle the additional power generated by the new R135 motor, all while improving overall efficiency.

 
The entire car has been optimised to improve performance and limit energy loss.
Éric Blanchard Director of Electric Vehicle Motors and Batteries at Renault

Does the push for efficiency also affect the services offered to the driver ?

Several of ZOE’s fittings and features contribute to the vehicle’s energy efficiency, such as regenerative braking and the various systems in place aimed at encouraging eco-driving best practices. The use of a heat pump instead of traditional resistance heaters also has a part to play, as do some of the connected features offered through the mobile application MY Renault. For example, it is possible to remotely set the cabin temperature, which is particularly impactful when the car is connected to a charging terminal: the energy stored in the battery can be saved for driving instead of climate control, maximising the available range.

 

 

*Worldwide Harmonised Light Vehicles Test Procedure, standardised cycle: 57% urban driving, 25% suburban driving, 18% highway driving.

Copyrights : OHM, Frithjof – Frithjof Ohm INCL. Pretzsch,  Yves FORESTIER

Most viewed articles