Denver to Offer New Transit Oriented Height Bonuses for Affordable Housing JetBlue to Reduce Carbon Footprint with Large Purchase of Renewable Jet Fuel 'Project Sidewalk' App Rates AccessibilityWhen it comes to renewables, the state of California has ambitious plans, with a goal to have a third of its electricity coming from renewables by the end of 2020, and half by 2030. With this push for change, electric vehicles are increasingly being seen as a clean, alternative mode of transport than can help drive down emissions. "The state of California has been extremely aggressive in… bringing in other states to have aggressive greenhouse gas goals and accomplishments: We at the city level are doing the same thing," Bob Hayden, from the San Francisco Department of the Environment, told CNBC's Sustainable Energy. For Arcady Sosinov, who lives in California and drives an electric vehicle, switching from gas has proved to be a boon. "I started using an electric vehicle to save money," he said.

"I knew how cheap it is compared to gas vehicles, but why I really loved using it is because of access to HOV (high occupancy vehicle) lanes, because of special parking and because I never have to deal with any maintenance," Sosinov added. A range of incentives have been brought in by the state to encourage the uptake of electric vehicles across California. One measure includes permission for single-occupant vehicles with a Clean Air Vehicle Sticker to use high occupancy vehicle lanes, as well as rebates of up to $5,000 for new zero emission or plug-in hybrid light-duty vehicles.air purification market size One organisation looking to encourage more people to adopt zero emissions vehicles is non-profit Charge Across Town. how to clean laptop with compressed air canThey say that the Bay Area is home to "more electric vehicles on the roads than any other region in the U.S."air purifier cost of electricity

For Meg Ruxton, partnerships manager at Charge Across Town, having a network to charge vehicles is just as important as getting people to purchase them. "I think we need to invest simultaneously in electric cars and charging infrastructure," she said. "Consumers are going to buy cars if there's charging in place, and businesses are going to put in charging stations if there are enough consumers with cars who are going to come and charge at their businesses," she added. Increasing usage of electric and hybrid vehicles stands to benefit both the environment and U.S. economy. The U.S. Department of Energy says that if hybrid or electric vehicles completely replaced light-duty conventional ones, U.S. dependence on foreign oil would fall by between 30-60 percent. Plus, carbon pollution from the transport sector would fall by up to 20 percent. "We've got a couple of benefits with electric vehicles," Hayden said. "Cutting down air pollution… because we do have health related problems related to diesel emissions and other vehicle emissions."

"We're cutting those down as well as reducing greenhouse gas emissions and protecting the climate. All of that comes together with electric vehicles." Across the world, more and more authorities are looking to encourage people to transition from using traditional gas-guzzlers to cleaner modes of transport. The city of Amsterdam, for example, has more than 1,000 charging stations, with Amsterdam City Council targeting 4,000 by 2018. What's more, all taxi journeys from the city's main airport, Schipol, are made in Tesla Model S electric vehicles. While electric vehicles have a clear benefit to the environment, there are other ways of fueling a car – or any kind of transport – in a sustainable way. For Arpad Horvath, a professor at the department of civil and environmental engineering at the University of California, Berkeley, biofuels could be part of the solution, though not in the immediate future. "The existing biofuel production system is unsustainable, the future will have to be based on plant waste or household waste or some other waste materials," he said.

"We're still figuring out the best way to turn them into biofuels at scale," he added.If you’re one of the lucky 85,000 California drivers of hybrids with yellow decals permitting access to carpool lanes, the free ride is over – for now. The state officially ends this program June 30 and will replace it with a new sticker program for electric and plug-in cars in the near future. While the wailing and complaining of frustrated hybrid drivers now joining the crushed masses in the regular freeway lanes is understandable, everyone knew this day was coming. The whole reason California got into the hybrid sticker access to carpool lanes in the first place was to jump-start the push toward vehicles with lower emissions. Since hybrids currently comprise 425,000 of the Golden State’s nearly 32 million vehicle registrations, that goal has certainly been accomplished. And it’s not like hybrid owners with those yellow stickers didn’t have a breather. The program had been set to expire at the end of 2010 but lawmakers approved a six-month extension to help ease the transition to cleaner, next-generation plug-in hybrids.

But drivers shouldn’t expect to get off with a warning if they're caught still driving in the carpool lane come July 1. Law enforcement isn’t going to be forgiving and will cite offenders for the infraction. That comes with a fine of at least $431. All is not bleak for the many California families with one or more hybrids in the household, however.  Come January 1, 2012, California will award 40,000 green bumper decals to owners of “partial zero-emission” plug-in hybrid vehicles. The new plug-in hybrid that Toyota plans to launch in the U.S. by June 2012 is one such next-generation PZEV, but production has been hampered since the March earthquake and tsunami. The 2011 Chevrolet Volt doesn’t currently qualify for the green-sticker program, and won’t until it meets stricter California standards, likely later in the 2012 model year. Tesla Roadster with CA Clean Air Vehicle sticker -- flickr user jurvetsonEnlarge Photo Choices in the meantime include switching to vehicles powered solely by batteries, or hydrogen or compressed natural gas -- vehicles like the Nissan Leaf, Tesla Roadster, and Honda Civic GX or Natural Gas model that runs on compressed natural gas.

These vehicles will qualify owners for an existing program of white bumper decals permitting carpool lane access. Other ways to ease the pain include changing work schedules to avoid rush hour, finding an alternate route, getting in a carpool with someone else going the same way, stocking up on books on tape, hitting up the boss to see if telecommuting one or more days a week is possible, or sticking it out until the new plug-ins arrive. What about other states allowing decaled-hybrid vehicle access to carpool lanes? Hybrid owners there don’t have to worry for now. Virginia, the first state to allow hybrid vehicle access to carpool lanes, plans to keep its program in effect to the end of June 2012. As for Arizona, Colorado, New York, Tennessee and Utah, these states plan to continue allowing access as long as traffic keeps flowing smoothly. Check out more on this issue in GreenCarReports. Sign up for our free newsletter or follow us on Facebook or Twitter.