Ten years ago Hawaii motorists looking for a more environmentally friendly way to drive to work or the beach didn’t have to do much research: They were pretty much limited to buying a hybrid vehicle.

That is about to change as an increase in the variety of "green" vehicles coming to market will compel consumers to understand the various technologies being employed under the hood and decide what vehicle best fits their budget and lifestyle.

General Motors plans to bring its first shipment of 20 Equinox hydrogen-powered vehicles to Hawaii by the end of this year, and Nissan will follow in early 2011 with the first order of its Leaf electric vehicles. Coda, a small company based in Southern California, says it will begin selling its electric sedan on Oahu by the end of the year. Other EV manufacturers, including Chevrolet and its Volt, also have their eye on Hawaii, as do makers of flex-fuel vehicles capable of burning up a mixture of up to 85 percent ethanol.

Toyota is also adding a plug-in Prius to its lineup that will offer drivers the option of using it as a traditional gas-electric hybrid or a fully electric vehicle. Toyota plans to introduce the car to the U.S. market in 2012.

Although no single technology has emerged as the favorite, having a greater number of green vehicle choices is good news for consumers and those working to reduce the state’s dependence on imported oil, said Jeff Mikulina, executive director of the Blue Planet Foundation.

"We might have a healthy ecosystem with different sorts of vehicles. Hopefully we’ll have a good mix of different technologies," said Mikulina, who drives a car that runs on biodiesel made from used cooking oil.

However, a recent survey suggests that the choices of green car technologies may be confusing for consumers. About half of 2,242 adults surveyed recently for Mercedes-Benz by Harris Interactive said they are interested in buying an alternative-fuel vehicle, but only 35 percent of those surveyed said they know which technology is best suited for certain types of driving.

"There is a plethora of vehicles coming to the Hawaii market, so people are going to have to do their homework and see what works best for them," said Dave Rolf, executive director of the Hawaii Automobile Dealers Association.

Hawaii is fortunate because the willingness of the government and consumers here to embrace new technologies means many companies view the state as a good place to test-market their cars, he said.

Rolf noted that just as Nissan chose Hawaii as one of the first markets to roll out the Leaf, so did Toyota when it launched the Prius in the U.S. in 2000.

State officials are looking at the adoption rate of the hybrid cars to gauge the public’s receptiveness to electric vehicles.

When the first hybrids arrived in Hawaii in 2000, a total of 46 were sold, including 31 Priuses, according to research done by R.L. Polk for HADA. Sales of hybrids increased by an average of about 90 percent a year before peaking at 1,235 vehicles in 2006. Sales have leveled off since then, partly do to the slowing of the economy. There were 1,047 hybrids sold in 2009, half of which were Priuses.