For one thing, there's disagreement over how much it should cost for the Capitol Power Plant--which provides heating and cooling power to Congress--to use cleaner-burning natural gas instead of coal power.

FORBES: The Greening Of The Hill

Supermarket giant Tesco has recently been given a green light to build Britain's first ever straw-powered Combined Heat and Power (CHP) plant to meet the electricity and heating needs of one of its distribution centres.

BBC: Time to encourage biomass growth

Rather than letting the heat escape, a cogeneration plant uses the excess energy to power a heating and cooling system.

FORBES: The Most Efficient Power Plants