"It's a mixed bag," said Neil Elliott, a director at the American Council for an Energy-Efficient Economy, a nonprofit research organization.

The American Council for an Energy-Efficient Economy, an environmental advocacy group, calls it the greenest car in America.

The American Council for an Energy-Efficient Economy, reports that investing in energy efficiency technology will save the average American household more than $4,000 by 2030.

Among the federally sponsored projects are the president's Freedom Car hydrogen vehicle program, according to the American Council for an Energy-Efficient Economy.

The Green Book is published by the American Council for an Energy-Efficient Economy, an environmental group in Washington.

The American Council for an Energy-Efficient Economy has explained that both resources must be developed in order to stabilize and reduce carbon dioxide emissions:

The American Council for an Energy-Efficient Economy, a Washington advocacy group, suggests consumers use a measure of return on investment.

The American Council for an Energy-Efficient Economy reviewed more than 36 different residential smart metering and feedback programmes internationally.

Even so, building owners and tenants will save $11 billion by 2000 because of the new law, the American Council for an Energy-Efficient Economy estimated.

He also serves on the Board of the non-profit American Council for an Energy-Efficient Economy.