The November elections are creating a narrow window for Congress to get a comprehensive energy bill to President Obama's desk by the end of the year, say lobbyists who are stepping up a full-throttled campaign to do just that.

"Staff has been working all recess … [but] one of the challenges will be the time left in the congressional calendar," said Greg Bertelsen, senior director for energy and resources policy with the National Association of Manufacturers.

"We have not had the president sign an energy bill since 2007. And it's long overdue," he said.

His group, which is the lead trade association for all manufacturing in the U.S., began fanning out during the summer congressional recess to meet with staff and lay the groundwork for a lobbying push when members return Sept. 6.

The House and Senate passed their versions of the major energy bill. Now it is up to a conference committee made up from lawmakers from both chambers to hash out the differences.

Bertelsen's group, and others that have joined the lobbying push to ensure Congress stays on course, are optimistic that the bill can pass this year, saying they think most of the heavy lifting has been done.

However, there is time for something unexpected, such as a controversial amendment or two. Controversy over funding issues and the water crisis in Flint, Mich., held up the bill's passage in the Senate for months.

"Any time a bill is moving, expect amendments," Bertelsen said. But "our objective is to get this bill passed."

The election is another hurdle for moving the bill. It "just shortens the calendar," Bertelsen said. Congress comes back in September, but leaves again in October. Then the lame-duck Congress will return in December.

Nevertheless, "I think it can happen this year," he said, adding that staff wouldn't have worked the entire August recess if they didn't think it could be done.

Lobbyists say much of what happens will be dictated by what Congress' schedule looks like in September, which won't be determined until lawmakers return. There is some concern that they may not stay the entire month.

"We know they have to fund government at some point," one lobbyist said, which means lawmakers probably will be in Washington through the beginning of October, since the fiscal year ends Sept. 30. Other bills waiting for action include funding the fight against the Zika virus and defense spending.

Industry lobbyists also are playing up the non-controversial aspects of the energy bill, especially those that benefit energy efficiency and electric transmission development. The heavy lift will be to merge the Senate and House bills, which aren't mirror images of each other.

Bertelsen and another group, the National Electrical Manufacturers Association, want to make sure key provisions to change how the Department of Energy conducts efficiency standards is included in the bill. Appliance manufacturers have gone to court over the standards because the way the agency devised the mandates doesn't allow them to understand the basis of the requirements.

The bill would change that by ensuring that the technical basis for the rule, called the "test procedure," is issued before the rule is final, giving businesses enough time to comment. As it stands, the agency issues the test procedure after the appliance standards are made final, which the industry sees as a backwards process.

The test procedure "is a big deal," said Joseph Eaves, director of government relations for the electric manufacturers that include big industry players such as General Electric. The House bill would require that the test procedure be issued for a certain time, he said, and the industry wants to make sure both chambers agree to include that.

Another top issue for manufacturers is the improvements the bill makes to the permit approval process for building transmission lines. Lines can take a decade to permit, but the bills seek to resolve that. The permit process can be bogged down because of the number of government agencies involved having to sign off on the lines, with no communication between one another.

The time it takes to complete a line is unacceptable for many of the manufacturers that have expertise in building the lines, Eaves said. It's "way too long," so the bill would place one agency in charge of moving the process along.

Eaves repeated what many lobbyists refer to as "non-controversial" fixes to major issues affecting the nation's energy infrastructure. The bill gives the energy secretary special emergency authority to protect the grid against cyber-attack, as well as direct studies on the barriers facing energy storage devices and other advanced grid technologies to make them a bigger part of the electric grid.

It also would expedite the Energy Department's approval process for shipping natural gas to other countries, which has been a major priority for the GOP and the oil industry.

Sen. Shelley Moore Capito, R-W.Va., is holding a field hearing of the Senate Energy and Natural Resources Committee in her home state on Monday. Her office doesn't expect the energy bill conference to come up, but it will touch on a theme in the bill of improving energy infrastructure.

A spokeswoman for the senator said Capito wants to use the hearing to address clean coal technologies that limit carbon pollution from going into the atmosphere, as well as other pollution control technologies being deployed at coal-fired power plants.

She also will address fracking in her state by examining key hurdles for developing storage facilities for natural gas liquids such as ethane, much prized by the chemical industry.

She also will use the hearing to discuss a bill she introduced this year to improve the pipeline permitting process.