KNOXVILLE, Tenn. — To the casual eye, the basement of this city’s Firehouse 9 looks like a jumble of old hydrants, Dr Pepper cartons, rakes and random gear. To specialists in energy efficiency, the 1960s-era building is a mess of a different sort: wasteful hot water heaters for the firefighters’ showers, ancient refrigerators and outdated lights.

Wrapping up an elaborate energy audit, Knoxville is about to find out which of 99 city buildings are wasting the most energy. It hopes to begin repairs this summer, just in time to catch a tsunami of federal stimulus money earmarked for such unglamorous tasks as replacing light bulbs and fixing leaky insulation.

Knoxville’s timing is excellent. The city began the arduous work of cataloging deficiencies before the stimulus bill passed, and it is well along in planning its next steps. But experts worry that other beneficiaries, especially cities, are not ready to oversee the huge sums of energy-efficiency money about to come their way.

The money in the bill is enough to pay for a tremendous expansion of efficiency efforts across the country. But as with other parts of the stimulus package, the efficiency plan is creating tension between spending the money quickly, to get rapid economic stimulus, and spending it well, to do the most good over the long run.