The base-level requirement for a car to meet for the green series' is a 'well to wheel' carbon footprint of less that 120g/km of CO2. Additionally, the cars must be of suitably high performance, turning quick laps, launching well at the drag race events and also capable of long-distance endurance events without the need for refueling.
Officials plan to 'performance balance' the varying cars a la FIA GT3 European Championship standards, which will likely include the addition of ballast to successful entries among other things. A field of six manufacturers, each with two car teams is hoped to offer a minimum grid size of 12 cars - scant even by modern formula standards, but the organizers are working to add more to the field.
Many standard race series have adopted 'green' fuels such as ethanol and ethanol blends to power their race cars, and many more have individual entries running alternative fuels on their own. The Indy Racing League, for instance, switched to 100% ethanol in 2005. American Le Mans teams, such as the Corvettes run by the factory, have been running on E85 for over a season.
The success of Audi's diesels in American Le Mans Series racing and at Le Mans itself is also well known. The world's first 'clean emissions' grand prix, the TTxGP, is already planning it's inaugural race for June 2009 at the historic Isle of Man. Formula One itself is planning to add a mechanical brake regenerative hybrid system, called KERS, into its cars by next year.
Whether the green angle will be enough to help the new 10-round enviroSportscar Series wedge itself into the already fiercely competitive world of racing remains to be seen, but a number of demonstration races held next year should let organizers know if they'll have the fan base necessary to carry the series off when it launches in 2010.