President Bush has challenged the congressional leadership to get energy legislation to his desk by the August recess. To do that, Rep. Joe Barton (R-Tex.) — chair of both the House Energy and Commerce committee and the 109th Congress edition of the energy conference committee — has set out an ambitious schedule, hoping to get a conference report to the House and Senate in time. Look out for politicos sporting slings as the arm-twisting starts this week. To help you keep track, here’s the Cliff Notes version of the marquee (and not-so-marquee) issues confronting the conferees. MTBE: In high doses, the U.S. EPA lists this gasoline additive as a potential human carcinogen, but it proved fatal to the energy bill in the last (108th) Congress. The House bill once again includes language that would protect MTBE producers from product liability lawsuits. The Senate bill contains no such language. Barton will have to solve the MTBE puzzle in order to get a conference report. He is working on a plan that would give producers liability protection and also establish an industry-funded cleanup trust fund. But will he be able to find a compromise that both industry and Senators facing billions of dollars of groundwater cleanup in their states can live with?

Ethanol: National security hawks and environmentalists concerned about climate change are warming up to this perennial Midwest-farmer favorite. The House passed a 6-billion-gallon-by-2012 renewable fuel standard (RFS). The Senate upped the ante to 8 billion, with extra credit for each gallon of cellulosic ethanol used.  An RFS seems all but inevitable; the only question remaining is, at what level? The smart money is on lucky number 7.

Arctic Refuge: The “sacred place where life begins” or “vast white nothingness”? Depends on who you ask. A stumbling block for the first attempt at an energy bill in the 107th Congress, the House bill once again included language that would open the Refuge to oil and gas development. The Senate included no such language, choosing instead to open the Refuge using the filibuster-proof budget process. The energy conference report will likely be silent on the Refuge, allowing the budget process to play out.

Renewable Portfolio Standard: In a close vote, the Senate adopted an amendment on the floor that would require 10% of our electricity to come from renewable sources by 2020. The House has no similar language, and heretofore Barton has opposed such efforts. Late last week rumors were circulating that he might go along with it if it were a “clean” energy portfolio standard that would encompass new nuclear power and advanced coal plants (as if those two energy sources weren’t getting enough support in the rest of the “uncontroversial” parts of the bill). Can moderate Republicans and Democrats in the Senate stomach that change? Some probably can; others probably can’t. You can be sure vote counters on both sides of the issue will be looking at the resolution to this closely. Will RPS be the new MTBE?

Global Warming: Who would have guessed that climate change would have generated the most energy on this energy bill? Over in the Senate, three amendments concerning climate change were offered, another was proposed. Eventually, incentives for climate-change-combating technology sponsored by Sen. Hagel (R-NE) and a Sense of the Senate to the effect that the time had come for mandatory limits on greenhouse-gas emissions were adopted — with the support of Senate Energy committee Chair Domenici (R-N.M.). This poses a problem for Barton, who is still questioning the science (and scientists) of global warming. He’d probably be happy keeping the Hagel language and ditching the Sense of the Senate, but will Senators — especially Senate Energy committee ranking member Bingaman (D-NM), whose language it is — let him?

PUHCA: Say what? That would be the Public Utility Holding Company Act. Before Social Security was the hot FDR/New Deal legislation to denigrate, there was PUHCA. If you think the Enron debacle was bad, it could have been a whole lot worse without PUHCA. So what do both versions of the energy bill do? Repeal it! The Senate threw in some extra merger oversight authority for the Federal Energy Regulatory Commission, but consumer groups say it’s not enough. Looks like if there is an energy bill, you can kiss PUHCA good-bye. But what, if any, safeguards will legislators leave to protect us the next time “the smartest guys in the room” come up with an idea?

Taxes: The one issue that is out of Barton’s hands. Instead, Rep. Thomas (R-CA) and Sen. Grassley (R-IA), chairs of the tax committees in their respective bodies of Congress, will have to hash out a compromise on taxes. The House’s package comes in with an $8 billion sticker price, skewed toward polluting industries. The Senate’s package would cost $18.4 billion over 10 years and is much, much greener. Rumor has it a $13 billion dollar level has been agreed to, but how the goodies get handed out is yet to be determined. In the end, the package will probably be close to an even split of green and brown. But will it happen in time to get the bill to the President’s desk before August arrives?

Looking for a more in-depth comparison of the two versions of the energy bills? Check this (PDF) out.