Compared with the last energy bill passed by Congress, which favored subsidies for oil companies over increases in renewable energy production or incentives for conservation, this year’s Senate version is a big improvement. That doesn’t mean, however, that it will do much to reduce our over-reliance on fossil fuels or America’s contribution to climate change.

With the bill passed in the Senate last week, regulation in many areas would finally catch up with technology. To end our addiction to oil, as President Bush has called for, regulations must push technological advancement, not trail it.

Take vehicle fuel economy, for example. It is positive that the Senate has finally passed an increase in what are known as Corporate Average Fuel Economy, or CAFE, standards. However, they will remain well below Europe’s, Japan’s and China’s, and worse, below what is technically feasible.

The Senate-passed bill would raise average mileage standards from the current 25 miles per gallon to 35 miles per gallon by 2020, which would be the first congressionally mandated increase since 1975. The standards can be lower if federal regulators find the ones set by Congress are not “cost effective.” Sen. Olympia Snowe, long a champion of higher fuel economy standards, helped negotiate a compromise to fend off weaker CAFE standards and to close a loophole that allowed light trucks and sport utility vehicles to meet lower standards.

“We’ve had the technology to make these advancements, but now we have the political willpower to finally achieve these goals and improve the future of our environment for generations to come,” Sen. Snowe said after the bill’s passage.

Maybe. A 2002 report by the National Academy of Sciences found that fuel economy could be increased by 50 percent, while maintaining vehicle size and performance and improving safety. Mid-size cars could average 41 miles per gallon, minivans more than 36 mpg and large pickup trucks nearly 30 mpg within 10 to 15 years, far quicker than the Senate energy bill required.

The current House energy bill doesn’t include fuel economy language, although Massachusetts Rep. Ed Markey has language similar to the Senate’s that he seeks to include in the bill. Reps. Mike Michaud and Tom Allen are co-sponsors.

The bill also raises efficiency standards for some common appliances. However, many of the new standards were negotiated between manufacturers and environmental groups, so this is another area where regulations are lagging technology.

Senators rejected increasing the country’s renewable energy supply to 15 percent, although a provision in that chamber’s final bill, authored by Sen. Susan Collins, calls for $275 million in federal funding over five years for research to develop low-carbon, alternative sources of energy, such as thermal, biofuels and bioproducts. Researchers at the University of Maine are examining ways to turn wood debris into ethanol.

This energy bill, which still faces more votes in the House and Senate, is an important step forward, but lawmakers have a lot farther to go.