Kate Sheppard has a handy overview of the big energy bill that just passed out of the Senate Energy and Natural Resources Committee. Bottom line: Environmentalists despise the bill, and it's likely to undergo heavy surgery on the Senate floor. The biggest brawl will likely be over offshore drilling:

A major concern for enviros and for some senators is that the bill would allow oil and gas drilling up to 10 miles off parts of the Florida coast, lifting a ban on drilling in the eastern Gulf of Mexico that Congress instated two and a half years ago.

Also, expect wrangling over the renewable-energy mandates and funding for new energy technologies—a lot of which could flow to coal and nuclear:

The bill includes a renewable electricity standard (RES) that’s weaker than the one being considered in the House as part of the Waxman-Markey climate and energy bill. The version in the Senate bill would require utilities to draw 15 percent of their electricity from renewable sources or energy-efficiency measures by 2021. Renewable-energy advocates have said that even the House version—which requires 20 percent of power to come from renewables and efficiency by 2020—is far too weak to make much a difference.

One of the notable dynamics in the ongoing climate/energy debate is that the House and Senate are taking two completely different approaches. In the House, Henry Waxman decided to put all his eggs into one bill: The American Clean Energy and Security Act includes a cap-and-trade regime for carbon emissions, a renewable-energy mandate for utilities, strict efficiency standards for buildings and appliances, money for various alternatives to fossil fuels, funding for smart-grid and electric-vehicle infrastructure…

The Senate, however, is doing climate and energy in piecemeal fashion. Barbara Boxer's Environment and Public Works Committee will oversee the regulation of greenhouse gases and crafting of a carbon cap-and-trade regime. Boxer's committee skews more liberal than the House energy committee, so their version of a carbon cap may turn out to be more stringent than Waxman's. (Earlier this week, Boxer told reporters that she was hoping to build off the Waxman-Markey framework, and could potentially crack down on offsets and strengthen the short-term targets for emission targets.)

Meanwhile, Jeff Bingaman's Energy and Natural Resources Committee is working on promoting renewable energy, setting efficiency standards, and overseeing new transmission lines. As Kate's piece implies, Bingaman's crew is far less "green" than Waxman's committee in the House. Plus, in the full Senate, there's a lot more resistance among "centrist" Democrats against acting aggressively on climate policy. Evan Bayh, for example, has threatened to block any moves to bolster the Senate's flimsy renewable-energy standard, even though the current version would barely improve on what states are already doing. And he may get his way. That 60-vote threshold, after all, is tough to clear.

That means it'll take quite awhile to pass and then reconcile all the House and Senate versions of these bills, and it's still wholly uncertain what the final outcome will look like.

--Bradford Plumer