“Not only was fuel expensive,’’ said the Boxford resident, 73, “it was difficult to get.’’

Awareness of the nation’s high energy consumption and dependence on foreign oil made Davis a local trailblazer in energy and environmental consciousness. He equipped his Kimball Road residence with solar panels, which have been heating the water in his home for 30 years.

Today, Davis and his wife, Carole, continue efforts to reduce their carbon footprint, including their decision to replace their gasoline-reliant vehicles with hybrids. They are not alone. Among communities north of Boston, Boxford has the second-highest percentage of registered alternative-fuel vehicles with 2.5 percent, increasing from a total of 28 in 2007 to 166 this year, according to the Registry of Motor Vehicles.

Locally, Boxford is second to Chelsea, which tops the state in alternative-fuel vehicles with 6.4 percent, catapulting from 12 in 2007 to 1,584 this year. Chelsea’s high numbers are largely a result of its commercial operations, such as rental car companies, which are attracted to the city by its proximity to Logan International Airport.

One of those companies, Enterprise Rent-A-Car, has about 5,700 flex-fuel vehicles distributed from Chelsea to approximately 180 locations throughout Massachusetts, New Hampshire, and Maine, said spokeswoman Lisa Martini. Although she did not have a specific number, Martini said many of those vehicles are registered in Chelsea. Of the 1,584 alternative-fuel vehicles registered in the city, 1,385 run on flexible fuel, a blend of gasoline and another fuel, such as ethanol.

Rounding out the five communities north of Boston with the most alternative-fuel vehicles are Winchester, Essex, and Westford, also at 2.5 percent each.

The number of alternative-fuel vehicles in the state has exploded since 2007, from 14,000 to more than 70,000. However, they still represent a fraction of the vehicles on the road: 1.7 percent. Of the state’s 4.2 million vehicles, including cars, trucks, and buses, 4.1 million are powered by gas.

The energy-efficient vehicles cover a wide variety of systems, ranging from hybrids that use electric and gas, compressed natural gas, electric, flexible fuel, and propane. By far the most common are the hybrids, such as the Toyota Prius, with more than 40,000 on the road in the state.

The Davises now own a Toyota Prius and a Ford Escape hybrid sports utility vehicle. “The cost of gas was going up and I wanted to do something about pollution and our use of gasoline,’’ Stephen Davis said. “As far as the Prius . . . I decided that I wanted to get a hybrid to make a statement about energy conservation.’’

Of Boxford’s 166 alternative-fuel vehicles, 99 are hybrids. Davis said most are Priuses.

“We are a very green-conscious community,’’ said Davis, who is also a selectman. “We recycle more than 50 percent of our rubbish; of the town buildings, two of them are Energy Star rated, which is an award for really reducing our energy consumption.’’

Just like in the 1970s, consumers altered their energy consumption habits when gasoline prices hit record highs in 2008, breaking the $4 a gallon barrier, said Paul C. Taylor, chief economist of the National Automobile Dealers Association.

“During the summer of 2008, there was a dramatic shift to focus on small cars by consumers, and dealers sold out of small cars,’’ Taylor said. “Our research suggests that if gas goes to $4.50 a gallon, you’ll see a shift like the one that occurred in the summer of 2008.’’

A combination of factors, including unrest in the Middle East and halted production in Japan resulting from the March earthquake and tsunami, has created high demand and short supply for alternative-fuel vehicles, Taylor said. Demand for the Toyota Prius, for instance, is so high that inventory averaged a 10-day supply last month across the United States, , compared with 56 days in April 2010, he added.

When demand exceeds supply, prices go up, even for used cars, said Alec Gutierrez, manager of vehicle valuation for Kelley Blue Book. “Dealers have to compete to get these vehicles in the lot,’’ he said. “As gas prices come down, we expect prices on these vehicles, including alternative-fuel vehicles, will come down.’’

The average price of a gallon of regular unleaded gas in the Boston area as of last week was $3.94, according to AAA Southern New England. It was $3.82 a month ago and $2.87 a year ago.

Many local communities have integrated purchase of alternative-fuel vehicles into capital improvement plans. In Chelsea, the first municipal hybrid vehicle was purchased in 2008 for the Parking Enforcement Division. “We’ve prioritized hybrid vehicles as part of our overall effort to reduce our energy consumption and promote sustainability,’’ said City Manager Jay Ash.

In Winchester, which went from 95 alternative-fuel vehicles in 2007 to 380 this year, there is a growing movement toward more sustainability, said George W. Wood, chairman of the town’s Climate Action Task Force.

“Through individual small groups and townwide efforts, we’re increasing the awareness of our citizens,’’ Wood said. “My office looks over Main Street, and just anecdotally, the number of hybrid vehicles that come by has increased dramatically. You see more parked on the street and in people’s yards.’’

Westford Town Manager Jodi Ross said it’s exciting that the town has the second-highest percentage of alternative-fuel vehicles among communities north of Boston, going from 102 in 2007 to 420 this year.

“We’re a community passionate about issues of the environment,’’ Ross said. “We have reduced our fuel usage. We negotiated with our unions to reduce the number of take-home cars. We initiated things like car pooling with the employees to try to control the cost of gasoline, and cutting on idling.’’

The water and building departments have one hybrid vehicle each, said John Mangiaratti, assistant town manager.

David Cash, assistant undersecretary for policy at the state Executive Office of Energy and Environmental Affairs, said gas hikes of 2007 and 2008 that steered people toward alternative-fuel vehicles coincided with the start of the state’s Clean Cities Coalition program, sponsored by the US Department of Energy, to promote use of those vehicles.

“The timing was perfect for our collaboration with the Department of Energy through the Clean Cities program, so we have been very aggressive providing funding for hybrid and electric hybrid vehicles, particularly in fleets,’’ Cash said. “We’re doing this both in government agencies, such as the MBTA and other transportation authorities, and also private companies as well.’’

The coalition’s next big push will be toward electric vehicles. A pilot program in the works is expected to bring about 200 federal- and state-funded electric vehicle charging stations to the state by the end of this summer, Cash said.

“The importance of piloting these programs is to show people the cost savings, the emissions savings. It’s really critical,’’ he said. “I think that people are looking at the history of energy cost. We got a huge price shock a couple of years ago.’’

For a list of alternative-energy vehicles in state cities and towns, go to www.boston.com/ yourtown/specials/snapshot/hybrid_cars_alternative_fuel_massachusetts_2011 Matt Carroll of the Globe staff contributed to this report. Katheleen Conti can be reached at kconti@globe.com.