More than half the people looking to buy a car in North America right now are considering hybrid vehicles.

They know they'll have to pay more, but for the extra cash they expect significantly better fuel economy compared to a similar model powered by gasoline only.

Despite hybrids often being less efficient than people anticipated, the market for them continues to grow.

Automakers see the demand for vehicles that are easy on the environment, and they know that reducing emissions is good for business and the earth, so they're coming up with better ways to make energy-efficient models.

Here's what different companies are doing, and how they're stacking up at going green.

BMW

BMW is credited with unveiling the world's first hydrogen-drive luxury performance automobile, the Hydrogen 7. It features an internal combustion engine that allows the vehicle to run on either liquid hydrogen or gasoline. On hydrogen, the vehicle essentially emits nothing but water vapour.

Despite the effort, it won't reach Canada yet as it's a limited-production model set for release only in the U.S., Europe and Japan later this year.

Lindsay Duffield, President and CEO of BMW Group Canada, and said that more hydrogen refueling stations need to open in Canada before the product can become mainstream.

Mercedes Benz

Mercedes received the Automobile Journalists Association of Canada (AJAC) award for Best New Technology for the new E320 BlueTec diesel technology.

The breakthrough clean diesel technology blends fuel efficiency to rival a hybrid without sacrificing power. The car is designed to reduce the soot and pollutants that are common with diesel engines.

Chief Executive Officer of Mercedes Benz Canada Marcus Breitschwerdt said the technology was so good that a white handkerchief stuck in the muffler for five minutes would come out without any change in colour.

General Motors

General Motors Vice-Chairman Robert Lutz said his company has 12 hybrid models approved for the market, five which will be available by the end of 2007. GM also expects to have a vehicle powered exclusively by hydrogen on the market by 2011.

There's also a battery-powered model on the company's horizon--the Chevrolet Volt a concept car not yet available for sale, will be a way to get to work without ever having to use gasoline if your roundtrip is less than 65 kilometres on pure electric energy.

"Simply plug in your car at night to recharge it, no stops for gas and zero emissions," Lutz said.

The small gasoline engine, which acts as an onboard generator, can extend the vehicle's range to up to 1,000 kilometres.

Toyota

Toyota has been recognized for its leadership in the field of fuel economy. The Yaris, Prius and Sienna each won the EnerGuide Award -- which recognizes the most fuel-efficient vehicles for 2007 -- in there field.

The Highlander Hybrid, the Prius and the Lexus RX 400h also made J.D. Power and Associates top 30 environmentally friendly vehicles for 2006.

The RX 400h was the only luxury hybrid to make the list.

Ford

Ford, who has won EnerGuide Awards for their Ranger and Escape Hybrid, recently came out with the SynUS Concept.

Deemed by the company as a mobile "Urban Sanctuary," the vehicle features a diesel engine with a transmission that is made to run on a 20 per cent mixture of environmentally conscious, Bio-Mass diesel fuel.

A big-screen TV is included in the design package.

The Escape Hybrid and the company's Mercury Mariner Hybrid were two of the three SUV hybrids to make J.D. Power and Associates top 30 environmentally friendly vehicles for 2006.

Honda

Honda had more vehicles make the J.D. Power and Associates top 30 environmentally friendly vehicles for 2006 than any other auto manufacturer.

The Accord and Civic hybrid models were two of the eight fuel alternative vehicles to make the list.

The Insight and the traditional Accord and Civic models also made it onto the top 30 because of their fuel efficiency.

The company placed second overall on the Automotive Environmental Index, which gauges a combination of fuel economy, air pollution and greenhouse gases.

Volkswagen

Volkswagen has yet to put a hybrid on the market. The company's Shanghai division is slated to begin selling a 2008 Touran Hybrid as part of the lead up to the Beijing Olympic Games.

But that doesn't mean their cars aren't eco-friendly: the company's a good example that fuel efficiency can be just as green as current hybrid designs.

The New Beetle, the Jetta, and the Golf all made J.D. Power and Associates top 30 environmentally friendly vehicles for 2006. Volkswagen had more non-hybrid vehicles on the list than any other auto maker.

They also finished first overall on the Automotive Environmental Index, which gauges a combination of fuel economy, air pollution and greenhouse gases.

For more on green cars, go to DiscoveryChannel.ca