|The Eco Elise, with rooftop solar panels. Click to enlarge.|
Lotus will unveil its “Eco Elise” technology demonstrator at the upcoming British International Motor Show, 23 July - 3 Aug in London. Unlike some of Lotus’ other initiatives, this demonstrator focuses less on tailpipe CO2 and more on materials, manufacturing and design.
Renewable materials. Sustainable hemp technical fabrics have been used as the primary constituent in the composite body panels and spoiler. The hemp fibers have also been used in the manufacture of the lightweight Lotus designed seats. An additional benefit of using hemp is that it is a natural resource that requires relatively low energy to manufacture. The hemp material is used with a polyester resin to form a hybrid composite. Lotus hopes that a fully recyclable composite resin will be viable in the short-term future.
The Eco Elise seats are upholstered in a durable yet biodegradable woollen fabric that has been given the EU Flower certificate—a recognized environmental quality mark independently verified and endorsed by the European Commission. This new material is ethically produced and does not use any dyes or harmful processing. The color is created from the selection of sheep breeds used to produce the wool for the yarn, which increases the natural feel of the wool and reduces the processing of the cloth.
Sisal—a renewable crop that, like hemp, is used for its strong material properties—has been used for the carpets in the Eco Elise.
Weight reduction. In keeping with the “performance through light weight” philosophy, the Eco Elise weighs 32 kg (70.5 lbs) less than the standard Elise S, yielding lower fuel consumption and better performance. The reduction in mass improves the handling and braking performance and also reduces the effort required to accelerate the car. The weight reduction philosophy has even extended to the audio system with an exceptionally lightweight stereo and speaker system from Alpine saving 1.5 kg (3.3 lbs). The system uses MP3/iPod technology.
The Eco Elise uses special lightweight wheels that reduce the unsprung mass and contribute a weight saving of approximately 15.8 kg (34.8 lbs) over the already super light Elise wheels.
Manufacturing. The Lotus Paint Facility, in partnership with Du Pont, has developed a totally water-based paint system. This paint solution includes primer, color coat and lacquer, and it is the first time that it has been possible to hand spray a water-based “A” class production paint finish.
In using this water-based technology, Lotus is able to achieve savings in energy consumption due to the low cure temperature this paint requires. An additional benefit of this paint system is the reduction in emissions of solvents, all of which contribute to substantial cost savings for Lotus. This technology is anticipated to be available in production cars in the near future.
Solar panels. The hemp hard top on the Eco Elise has two flexible solar panels neatly embedded in the roof, contributing power to the electrical systems and saving energy that would be drained from the engine.
The solar panels have been integrated into the hard top to illustrate the feasibility of applying this technology. This application shows the installation of solar panels into a composite “A” class panel with a double curvature. Using this technology on a greater number of panels would make it possible to provide more power, especially on a larger vehicle.
Reduction in carbon miles. The hemp fibres have been farmed in East Anglia, thus reducing the carbon miles incurred in the production of this Elise. Lotus Manufacturing has component manufacturing facilities and a paint facility at its headquarters in Hethel, Norfolk, with another manufacturing site a short distance away in Norwich. The company operates a carefully managed logistics system operating between sites to improve efficiency, reduce costs and carbon miles. This is a Kanban driven barcode system that has been adopted by key suppliers. The process also uses packaging that is recycled many times over to eliminate waste.
Efficient driving techniques. Lotus cars have red shift lights to help drivers extract the maximum performance from the engine. However for the Eco Elise, Lotus designed software has been developed to assist drivers in maximizing the fuel efficiency of the engine. A green gear shift display has been integrated into the instrument panel to ensure that gears are changed at the optimum point to reduce emissions and save fuel.