Gov. Dannel Malloy released a long-awaited comprehensive energy strategy for the state of Connecticut on Tuesday.

The plan, which the governor unveiled at several stops across the state chosen for their energy efficiency, includes an expansion of natural gas consumption as well as higher energy-efficiency standards. Malloy first expressed interest in reforming the state’s energy policy in 2011, when he proposed legislation that would consolidate state functions — from electricity and oil to heating and transportation — into the state’s Department of Energy and Environmental Protection, according to DEEP spokesman Dennis Schain.

Schain said the legislation, now known as the Energy Bill, called for a major energy strategy that would help DEEP run more smoothly.

“[Malloy’s] feeling was that the state had not been thoughtful enough about energy issues and that we were suffering from high prices for electricity and were ill-prepared for the future,” Schain said.

The most controversial aspect of the new plan is its expansion of natural gas infrastructure and consumption. Speaking at Royal Ice Cream, a Manchester-based small business that saved 50 percent of its energy costs when it switched to natural gas, Malloy called on utility companies to build 900 new miles of natural gas lines in the state and offer customers the option to switch their energy consumption to natural gas. His plan also includes a proposal to offer a $500 tax credit to customers who make the switch.

Many aspects of the plan require legislative approval before they go into effect, while others can be implemented through executive action.

When Malloy released the first draft of his energy strategy last October, opponents, such as home heating oil dealers, came in droves to testify against natural gas expansion. One of the recurring complaints was the cost of new natural gas infrastructure — a puzzle that the Malloy administration solved by placing the burden of cost on utility companies rather than on taxpayers.

But Dan Fischer, a community organizer for the Connecticut Coalition for Environmental Justice, opposes the use of natural gas due to its negative impact on the environment. When natural gas is extracted from the ground, he said, it pollutes drinking water and contaminates the lungs of workers extracting it. Moreover, he added, several studies have shown that producing natural gases emits more greenhouse gases than burning coal.

Other aspects of the governor’s energy strategy are more widely supported. Much of the plan focuses on creating higher energy-efficiency standards in areas such as the state’s energy grid and its public transportation system. The strategy also urges the state to expand its use of renewable energy.

“That’s the basic building block: Reduce demand and therefore bring down bills,” Schain explained.

Mark LeBel, an energy fellow for the Connecticut Fund for the Environment, said that the strategy highlights Connecticut’s position as one of the country’s leaders in energy and climate change policy. The state is just one of a few to have an established greenhouse gas reduction target — a 10 percent decrease from 1990 emission levels by 2020 — which it is on target to meet. Still, he added, Connecticut cannot implement policies as strict as those in California, such as implementing an economy-wide cap-and-trade law.

“[California is] so big and less dependent on regional trade and travel,” LeBel said. “So for Connecticut, you might expect a lot of people would move to New York or elsewhere in the region if they are not pleased with Connecticut’s standards.”

In a poll released last week, the conservative think tank Yankee Institute for Public Policy found that 54 percent of Connecticut residents approve of Malloy’s performance as governor.