Concept Preview: Lotus Sports Car

Many of the same engineering and design parameters apply to both high performance and green performance. In fact, the two are often intertwined, employing the same design goals and disciplines in pursuit of parallel technologies. Take, for example, the quest for weight reduction. Moving less mass translates directly to better acceleration, shorter stopping distances, and improved cornering ability. Reducing weight is also a primary factor in improving fuel economy and reducing emissions.

In the spirit of company founder Colin Chapman, few automakers in the world can match the Lotus knack for innovative design and engineering. Those talents are clearly evident in Lotus' latest green design study, the Eco Elise. Unlike many green concept cars that focus primarily on tailpipe emissions, Lotus approached the Eco Elise project as a systemic start-to-finish effort with an eye on sustainability.

Most notable in the Eco Elise is the use of organic renewable materials throughout the car. Sustainable hemp technical fabrics, for example, are used in the composite body panels and spoiler. Hemp's strong fibers are used in place of a carbon fiber mat in the composite panels. Farming the hemp locally reduces the overall carbon miles required to produce the Eco Elise. Growing the hemp also absorbs CO2 as a natural part of the plant's photosynthesis process.

While the hemp fabric is bonded with a polyester resin in the hybrid composite, Lotus is hoping a fully recyclable composite resin will be available in the near future. The body panels are coated with a water-based paint system that the Lotus Paint Facility developed in partnership with Du Pont. With the very low cure temperature the water-based process requires, Lotus is able to realize a significant energy reduction along with fewer solvent emissions.

Hemp fibers are also used to produce the lightweight seats designed by Lotus. The seats are covered in a renewable, biodegradable natural wool fabric. Rather than using harmful dyes to color the fabric, Lotus designers carefully selected the breeds of sheep used to achieve the desired color palate. Carpeting can also be a less-than-environmentally-friendly material, so Lotus turned to sisal, which like hemp is a renewable crop with very durable properties.

A pair of flexible solar panels is bonded into the roof structure of the Eco Elise. These panels collect energy that's converted to electricity for powering systems in the car, relieving some of the charging energy normally drained from the engine. The solar panels are impressive because they are embedded in a complex double curvature in the roof line, illustrating how the technology can be applied to a wide range of surfaces.

Lightweight designs are central to the Lotus brand philosophy. Compared to the standard Elise S, weight in the Eco Elise has been trimmed by an impressive 70 pounds. The Eco Elise has special lightweight wheels that reduce the unsprung mass of the car and trim about 35 pounds from the overall package. Not so obvious areas were also scrutinized in the weight reduction process. Lotus was even able to save just over three pounds by installing a special featherweight Alpine sound system with MP3/iPod technology.

The green efforts are company-wide at Lotus, too. In the span of just one year, Lotus has reduced energy usage with a 14 percent decrease in electricity and 30 percent decrease in gas, while cutting water use by 11 percent at the company's Hethel, England headquarters. During the same period there's been an increase in recycling waste products, to the tune of 57 percent.

Lotus is certainly not new to the green car scene, with recent concepts like the E85 Lotus Exige 265E and the Lotus Exige 270E Tri-Fuel sports car, which can run on gasoline, bioethanol, or methanol. And let's not forget that the much-anticipated Tesla Roadster electric car is based on the Lotus Elise. Lotus Engineering is an integral part of the Zero Emissions London Taxi Commercialization project that's planning to introduce a fleet of fuel cell hybrid taxis to London in 2012 and other cities by 2014.

The Eco Elise is a refreshing design exercise that clearly illustrates that in the future the green car movement will be waged on many levels with an ultimate goal of sustainable mobility.