Characteristic components of an EV. Click to enlarge.		Optimizing energy consumption. Click to enlarge.

From 2011, Renault will progressively roll out four electric vehicles, including two derivatives of internal-combustion vehicles. The first will be the electric version of Fluence (earlier post) which will initially be available in Israel and Europe. The second will be an electric version of Renault Kangoo Express, intended primarily for fleet and business use.

The range of electric vehicles will then expand to cover other segments, with two vehicles that will be designed from scratch as electric vehicles. Derived from the Twizy ZE Concept, the third vehicle will target urban mobility. The fourth vehicle, which takes its inspiration from Zoe ZE Concept, will go on sale at the beginning of 2012 and will be a multi-purpose daily driver for built-up areas.

The power electronics and electric machine unit. Click to enlarge.		Lithium-ion battery pack. Click to enlarge.

Twizy ZE Concept. Twizy ZE Concept is an ultra-compact (2.30m in length, and 1.13m wide) all-electric vehicle aimed primarily at city dwellers. Power comes from a 15 kW (20 hp) electric motor which develops 70 N·m of torque; the transmission is a direct drive with reducer and forward/reverse inverter.

Twizy ZE Concept. Click to enlarge.

The acceleration performance of Twizy ZE Concept in urban and suburban traffic is comparable to that of a 125 cc motorbike, according to Renault. The EV has a top speed of 75 km/h (47 mph), and a projected range of 100 km (62 miles).

The lithium-ion batteries for Twizy ZE Concept are located beneath the two seats. They are charged by means of an extendible cable located behind the Renault logo at the front. This cable can be plugged into a 220V 10A or 16A domestic socket, and will fully charge the batteries in three and a half hours.

Zoe ZE Concept. Click to enlarge.

Zoe ZE Concept targets motorists who own more than one car and who are looking for a compact, versatile vehicle capable of meeting their varied day-to-day needs, such as the school or work run, or shopping trips.

Zoe ZE Concept is 4.10m long and is powered by a 70 kW (95 hp) electric motor which develops 226 N·m of torque and a direct drive with forward/reverse inverters. Top speed is 140 km/h (87 mph), and projected range is 160 km (99 miles). Zoe ZE Concept uses electric variable rate power steering and an electric parking brake.

At the rear, a retractable spoiler deploys at speeds in excess of 90 km/h (56 mph) to contribute to Zoe ZE Concept’s aerodynamic efficiency. This LED-equipped spoiler also serves as a brake light, as does the integrated light in the shark’s fin-type aerial on the roof.

The driver has three options when it comes to recharging: standard charge, quick charge and Quickdrop. Air intakes situated either side of the car channel airflow to cool the batteries. The air is extracted through two large rear channels through which it is possible to glimpse the suspension arms.

Some of the other features on the Zoe ZE Concept include:

• Rearward vision is handled by two small, profiled, energy-efficient cameras which transmit images to the interior rear view mirror, giving the driver perfect visibility without blind spots.

• The front features scissor doors, while rear access is through butterfly-style doors. The design of the rear doors means they also double up as openings for the trunk, allowing carrying space to be accessed from the side, from the pavement, for example.

• The climate control system offers a three functions in addition to adjusting the temperature. A hydrating function sprays an active substance to rehydrate the skin; a detox function uses toxicity sensors to monitor air quality and shut off airvents if required; and an active scent function that exhales essential oils (aromatherapy in the car). This triple-function system was developed in association with Biotherm, the skin biology brand of L’Oréal’s Luxury Products Division.

The Fluence ZE Concept on the road. Click to enlarge.

Fluence ZE Concept. Fluence ZE Concept previews the forthcoming electric version of Fluence, and is a family car with a range of 160 km (99 miles). The battery can be charged using one of three methods: a standard charge (between four and eight hours), a quick charge (20 minutes) or an immediate solution (three minutes) in the form of the Quickdrop rapid battery exchange system.

Fluence ZE Concept is powered by a 70 kW (95 hp) motor that develop 226 N·m of torque, and a direct drive with forward/revers inverter. It uses electric variable-rate power steering.

Photovoltaic cells located on the panoramic roof, dashboard and rear parcel shelf meet part of the car’s energy requirements with a view to complementing the power supplied by the battery. The headlights use high-performance electroluminescent diodes.

The Kangoo ZE Concept. Click to enlarge.

Kangoo ZE Concept. Kangoo ZE Concept is based on Renault Kangoo and also is powered by the 70 kW electric motor with 226 N·m of torque.

The use of heat-reflective paint and bodywork featuring large surface areas reduces temperature fluctuations. The bodywork functions along the same lines as a Thermos flask and comprises two insulating panels with a sandwich of air in between. This air serves to moderate temperature extremes between the exterior and the interior of the car. Thermal insulation is further optimized thanks to special treatment of the glazed surfaces, meaning that less call is made of the climate control and heating systems which are big consumers of energy.

Solar panels positioned on the roof are employed to power a temperature regulation system inside the car.

The Kangoo ZE Concept supports either a standard charge or quick charge.

Charging and Quickdrop. A standard charge using a domestic 220V 10A or 16A socket requires between six and eight hours in order to charge an electric vehicle. This method is best suited to a car parked overnight in a private parking area or during the working day in a shared car park. A secure automatic key system is designed to prevent vandalism from disconnecting the cable during charging.

This type of charging point can easily be incorporated in a private garage, or in shared domestic parking areas. The plug socket can be easily adapted to the current grid by an electrician.

In France, EDF and Renault have been working together since October 2008, and recently signed an agreement for a Power Line Communication (PLC) system. This allows confidential data transfer between the charging point and the vehicle while the battery is being charged, such as the vehicle’s identity or billing information, for example. (Earlier post.)

A quick charge employs a 400V socket capable of operating from 32A to 63A triple phase using infrastructure that is under development. This system will charge a 20 kWh battery in 20 to 30 minutes, according to the available current. Charging points will be installed close to residential areas, offices or shops.

A group of 20 manufacturers, including Renault, as well as energy providers, have been working with the German company RWE on the development of a multi-purpose common charge plug that will cover the range of electricity from 230V/16A single phase to 400V/63A triple phase. This specification will allow charging infrastructures to be normalized across Europe, while also taking into account the variable capabilities of the different power grids and electric vehicles.

The standard charge plug was launched last April in Hanover and will be suitable for recharging Renault’s forthcoming range of electric vehicles. Approval by the usual standardization authorities (ISO, IEC) is currently underway.

The Quickdrop system, developed in collaboration with Better Place, supports the use of rapid battery exchange stations. The automatic battery exchange process takes approximately three minutes. In May, Better Place unveiled its automated battery switch system in Yokohama. (Earlier post.)

The battery exchange station will resemble a car wash, in the sense that the driver will enter the facility and stop the car in a precise location. This will allow the robot positioned underneath the vehicle to easily locate the attachment points of the battery that needs to be replaced.

The system operates with two battery change robots on an automatic conveyor. The first robot takes the fully-charged battery that will be inserted, while the second removes the empty battery. At the end of the process, the conveyor belt transports the empty battery to a storage area where it is quick charged in 20 to 30 minutes and then re-employed in another electric vehicle.

The battery change robots have been designed to work with varying battery sizes which will allow them to handle different brands of electric vehicle. This is because the first electric vehicles to reach market will be modified versions of internal combustion vehicles. Renault says that it expects that fully electric vehicles will be designed around a common battery standard.

The only restriction is the need for a standardized system of battery attachment points to allow the robot to work as quickly as possible.

The battery exchange technology on display in Frankfurt indicates the state of progress of the project, which will be rolled out in Israel initially. Battery exchange stations will be built to enable journeys longer than 150km, or for specific uses such as taxi fleets. For example, the majority of taxis in and around Paris cover between 140 and 200km a day. They would need just one battery change to complete a day’s work.

Both at rapid charge points and at rapid battery exchange stations, the intention is to introduce a system which permits automatic recognition either of the charging socket or of the car itself in order to enable automatic billing. Drivers won’t even need to get out a credit card.

Intelligent navigation for range optimization. Renault says that range optimization is the greatest challenge for electric vehicles. In addition to the HMI (human-machine interface) to inform the driver of the vehicle’s remaining level of charge and range, a new navigation system gives a precise indication of:

• the location of the nearest charging points or battery exchange stations;
• advance reservation of a charging point;
• the precise remaining range; and
• the optimum itinerary, taking into account the vehicle’s range and the location of charging points.