PORTLAND — If given about 20 minutes, the new electric car charger being installed at the Hyatt Place hotel can deliver roughly 80 miles of range.

It will be the most powerful charger north of Boston, according to its developer Tim Soley. It is a project environmentalists, businesses and policymakers are pointing to as a sign of growing support and adoption for electric vehicles in Maine.

Dylan Voorhees, spokesman for the Natural Resources Council of Maine, said Thursday morning over a din of car traffic along Presumpscot Street that at least 150 all-electric cars are on the road in Maine, and he estimates there are more, based on records from the Bureau of Motor Vehicles. Roughly half are registered in Cumberland County.

Adam Lee, chairman of Lee Auto Malls, said during a Thursday media event outside the offices of solar panel installer ReVision Energy his dealership sells about 20 hybrid and electric vehicles a month, between the hybrid Toyota Prius, its plug-in variant and the all-electric Nissan Leaf.

“When they first came out they didn’t sell, but we’ve gotten past that point,” Lee said.

For his dealership, Lee said decreasing cost, more charging options and a rising range of electric vehicles are helping change the attitudes of consumers, most of whom lease the electric vehicles. Lee said state law that requires manufacturers to sell a certain number of zero-emissions vehicles are also compelling lower prices in the cases when car makers are looking to meet their quota.

“If it seems expensive, wait,” he said he tells customers, noting manufacturer subsidies can drop the monthly lease price on a Nissan Leaf by a third, to around $199 from $300.

The car retails for roughly $30,000, and users can qualify for federal tax credits to lower the cost, according to Nissan.

Lee’s Auburn and Topsham dealerships added charging stations two years ago, and a state pilot program is helping to fund new charging facilities at employers like the Westbrook-based Idexx. Matt Haas, Maine operations manager at Idexx, said a $2,500 grant through Central Maine Power’s pilot program with the Maine Public Utilities Commission prompted the company to move ahead with a plan to install four charging stations for its workers — a $10,000 investment from the company.

Usage statistics from those charging stations and others in the pilot project will provide data the PUC will use to study the performance of electric vehicles and their impact on the state’s power grid. Other grant recipients in the program’s first phase include the Maine Organic Farmers and Gardeners Association, Colby College, Lewiston-based HVAC company Fresh Air Ventilation Systems, E2Tech and the Greater Portland Council of Governments.

ReVision Energy, the site of Thursday’s press conference, is one of five locations in the state with electric vehicle charging stations, according to the PUC. The other locations are Lee’s Auburn and Topsham dealerships, Bill Dodge Nissan in Saco and the Acadia Welcome Center in Trenton. The Trenton charger is half the voltage of the others in the state.

Voorhees said the increased adoption of electric cars stands to have emissions benefits over traditional cars and reduces the state’s dependence on oil. While the electricity pulled from the grid is generated in most cases by carbon-emitting power plants, a regional study from the Union of Concerned Scientists found a gasoline-powered car would need to get more than 75 miles per gallon to have fewer emissions than a car running off power from New England’s energy grid.

“The cleaner our power plants are, the cleaner our electric vehicles are,” Voorhees said. “And Maine has one of the cleanest grids.”

The study found power plant emissions in other regions were worse. By comparison, a car getting more than 38 miles per gallon in Michigan would have lower emissions than a car using electricity generated by regional power plants.

Voorhees said analysis of data from the state’s pilot project should be completed within a year, providing regulators more guidance on the benefits and challenges of adding more capacity for electric cars to the grid.

But some are getting ahead of the curve.

Soley, developer of the Hyatt Hotel and its neighboring solar-paneled parking garage, said his Tesla Model S, which retails for more than $60,000, is his third electric car. The company, whose sporty electric vehicles can go up to 260 miles on a single charge, sells directly to customers — a practice car dealerships have successfully fought in some states — and has started building out its own network of 120-kilowatt “superchargers” that can provide nearly 170 miles of range in 30 minutes.

Tesla has said it would install one more of its high-powered chargers in Maine before the end of the year, Soley said.

The power will be free for the chargers being installed at his parking garage this week, but the parking still comes with a charge.