It’s a huge undertaking that not only requires replacing the current fleet of buses, but also building charging stations to power them.

But change is on the way. When the work is done, it will mean cleaner air, cleaner lungs, and fewer cases of asthma and other lung diseases.

“That will happen in five to ten years,” said Richard Schreiner, chief executive officer of HARTransit, which operates bus services in the Danbury area. “I think it will happen on the low side this time.”

“It’s very exciting,” said Katie Dykes, commissioner for the State Department of Energy and Environmental Protection. “It can’t come a moment too early.”

In December, Governor Ned Lamont signaled the state’s commitment to a fully electric bus fleet as part of an ordinance on a variety of environmental issues.

In response to that order, Lamont directed the State Department of Transportation to stop buying or allocating funding for diesel buses by the end of 2023.

The DOT and some cities are already moving in this direction. There are two electric buses in Bridgeport and one in New Haven, with more on the way.

The state is also using $ 12.7 million of its $ 55.7 million settlement with Volkswagen to purchase 43 electric school buses that will be used in seven communities including Bethel and Stamford.

The DOT is investigating the use of electric buses in other locations.

Schreiner said the DOT will analyze the HARTransit area this year. The DOT report will provide a blueprint for future electrification of its buses.

One of the things to be clarified is how a new fleet should be paid for. The up-front costs of electric buses are high.

According to a report by the American Public Power Association, a diesel transit bus can cost about $ 500.00 and an electric bus about $ 750,000. A diesel school bus costs about $ 110,000 and an electric school bus about $ 230,000.

But electricity costs much less than diesel fuel, and electric vehicles require less maintenance – no oil changes, no mufflers and no exhaust system.

Ridgefield First Selectman Rudy Marconi said the city used grants in 2014 to buy an electric Nissan Leaf that city officials use in their daily work

The overall savings on fuel, maintenance, and servicing made the car a bargain, he said.

“Absolutely,” said Marconi. “Without doubt.”

Since buses travel a fixed route and return to a fixed location, they are ideal candidates for an electric fleet – charged at night in the bus station and ready for use in the morning.

However, Schreiner said there are wrinkles that need to be carved out. The HARTransit system covers an area from Norwalk to New Milford, so more than one charging center may be required.

In addition to its 28 local buses, it has 32 smaller buses that it uses for services such as its SweetHART routes for seniors and people with disabilities.

“The entire system has to be configured for all of these things,” said Schreiner.

But the environmental benefit – cleaning the air of the state – would be great.

DEEP levees said Connecticut consistently fails to meet federal environmental agency standards for clean air.

That’s partly because of geography. The prevailing winds blow pollution into our skies from coal-fired power plants in the Midwest and from the Washington DC-Philadelphia-New York corridor.

But 69 percent of the state’s air pollution comes from car exhaust, Dykes said. 40 percent of this comes from buses.

Diesel fumes add to the state’s carbon dioxide emissions and fuel climate change.

But they also emit high levels of nitrogen oxide and fine dust, which heat up the smog and bad air days in summer.

Dykes said this contributes to the state’s high rates of asthma, particularly in downtown areas and along the transit routes that buses run on.

She said about 11 percent of the state’s children and 10.5 percent of adults have asthma, with rates higher in some large cities. Overall, asthma treatment costs about $ 100 million a year in the state.

A fleet of electric buses therefore saves money across the board. And people can be healthier.

“That means clean air for children and adults,” said Dykes.

Contact Robert Miller at [email protected]