US President Barack Obama addressed the Energy Department on Thursday, although employees looking for a little inspiration or insight into their future at the agency might have come away disappointed; the renewed bid for a green economic stimulus bill was clearly directed at senators who were busy debating the legislation on Capitol Hill.

The president reiterated calls for a vast new investment in energy efficiency and renewable energy technologies, all of which will be needed to end “the tyranny of oil.” He said a modernized grid on its own could reduce energy consumption by 2 to 4 percent; retrofitting federal buildings would put people to work and cut the government’s energy bills by $2 billion annually.

“Washington might not be ready to get serious about energy independence, but I am,” he said. “No plan is perfect … but both the scale and the scope of this plan is the right one. Our approach is the right one.”

The House of Representatives passed its $825-billion stimulus bill on 28 January, including roughly $13 billion for basic research and development as well as tens of billions for clean energy initiatives. The Senate is busy working on its own version this week; the bill started out at $888 billion (see “American Recovery and Reinvestment Act of 2009”), although Republicans and some Democrats are working to scale that number back.

Much of the focus is on the housing market and the banking sector, but lawmakers have also debated the inclusion of coal and nuclear power. Speculation abounds (check here and here) that the stimulus money will revive the Energy Department’s controversial FutureGen project, a public-private partnership to build a coal-fired power plant that captures carbon dioxide and pumps it underground. The Bush administration cancelled the project last year, but FutureGen’s backers have not given up.

Senate Democrats say they expect to pass the legislation (with the help of a few Republicans) later today. If they do, the House and Senate would then need to negotiate and pass a compromise bill. Obama is pushing for all this to be done by mid-month.

As it happens, standing beside the president during the press conference was Energy Secretary Steven Chu, who made headlines Wednesday by suggesting that California’s agriculture sector – and its cities – could perish by the end of the century if global warming isn’t addressed. Fresh water is clearly a problem, particularly in California, but some have suggested that Chu might have overstated things a tad.