WASHINGTON – The Energy Department has agreed to boost energy efficiency requirements for nearly two dozen household appliances and equipment from dishwashers to fluorescent lamps as part of a court settlement after years of inaction.

The new standards will be phased in over the next five years.

The agreement, filed in the U.S. District Court in New York and announced Monday, settles a lawsuit filed last year by environmental groups, 15 states, including Maine, and the city of New York because of delays in improving federal appliance efficiency requirements.

Kit Kennedy, an attorney for the Natural Resources Defense Council, which was among those who brought the lawsuit, called the agreement a “historic opportunity” to save consumers energy costs.

She said the new requirements, once fully in place, could save enough energy to meet the needs of 12 million households and avoid building dozens of new power plants.

“This common-sense standards will save consumers money, lower our dependence on foreign oil and improve public health and our environment,” New York Attorney General Eliot Spitzer, the state’s governor-elect, said in a statement in Albany.

Critics of the Bush administration’s energy efficiency efforts said some of the standards have been long overdue. The lawsuit charged that the Energy Department was 13 years late in meeting a number of the requirements, although Congress required that appliance standards be updated.

The court agreement calls for the new standards to go into effect at varying times, the earliest in early 2007 and the latest by June 2011.

The standards will cover 22 appliances and household equipment, including heating and air-conditioning systems, water heaters, boilers and motors, dishwashers, clothes dryers and fluorescent lighting.

Under the agreement the department must set standards at the maximum technologically feasible and cost-effective level possible and cannot weaken established standards, said Kennedy.

The department came under criticism last month when it proposed new efficiency requirements for household furnaces that efficiency advocates said were insufficient.

Those standards, which would go into effect in 2015, establish a standard for widely used natural gas furnaces only slightly greater than what was required 20 years ago and at a level that virtually all of the furnaces now on the market already meet.

It was not immediately clear how the furnace proposal would be affected by the court agreement.

In addition to New York and Maine, states involved in the lawsuit are California, Connecticut, Illinois, Iowa, Massachusetts, New Hampshire, New Jersey, New Mexico, North Carolina, Pennsylvania, Rhode Island, Vermont and Wisconsin.

The Texas Ratepayers’ Organization and the Massachusetts Union of Public Housing Tenants, two advocacy groups for low-income consumers, also were plaintiffs.