President Obama is giving top billing to clean energy and green jobs as he promotes his $3.6 trillion budget plan.

Addressing a group of clean-tech entrepreneurs and researchers on Monday, the president noted that his proposed budget includes $150 billion over 10 years for direct investments in clean energy and efficiency, as well as $75 billion to make permanent a tax credit for research and experimentation. “At this moment of necessity we need you, we need inventiveness,” he told the crowd.

“We can remain the world’s leading importer of foreign oil, or we can become the world’s leading exporter of renewable energy,” Obama continued. “We can allow climate change to wreck unnatural havoc, or we can create jobs preventing its worst effects. We can hand over the jobs of the 21st century to our competitors, or we can create those jobs right here in America.” The event was the first in a series of budget pep talks the president plans to give this week.

Obama made similar points on Saturday in his weekly address. He acknowledged that the details of a budget will shift as Congress hashes it out, but said a final plan must meet four basic principles, the first of which centers on clean energy:

[A budget] must reduce our dependence on dangerous foreign oil and finally put this nation on a path to a clean, renewable energy future. There is no longer a doubt that the jobs and industries of tomorrow will involve harnessing renewable sources of energy. The only question is whether America will lead that future. I believe we can and we will, and that’s why we’ve proposed a budget that makes clean energy the profitable kind of energy, while investing in technologies like wind power and solar power; advanced biofuels, clean coal, and fuel-efficient cars and trucks that can be built right here in America.

In information sent to reporters on Monday, the White House outlined two examples of the types of green projects it wants to invest in — the Apollo Light Pipe, recently patented by Orion Energy, which collects and focuses sunlight so it can be used indoors; and cylindrical solar panels produced by Solyndra, the first company to receive a loan guarantee from the Department of Energy with funding from Obama’s economic stimulus bill.

All of this comes in advance of what will likely be a tense few weeks of budget negotiations as Congress begins formal debate on the proposal that Obama first unveiled almost a month ago.

A climate plan in the budget bill?

One particular hot spot in Obama’s budget is a cap-and-trade plan to curb greenhouse-gas emissions. The budget includes $79 billion in “climate revenues” that it projects will be raised from the auction of carbon credits by 2012. It sets aside $15 billion a year from those revenues to develop technologies like wind, solar, and advanced automobiles, and would return the remaining funds to consumers via tax credits.

There’s been some talk in recent weeks of Congress following Obama’s lead and including a cap-and-trade plan in a budget “reconciliation” bill, which would need only a simple majority of 51 votes to pass, rather than the 60 votes required under normal Senate rules. But the likelihood of that seemed to dim over the weekend as Senate Budget Committee Chair Kent Conrad (D-N.D.) told ABC’s “This Week” that he doesn’t intend to include cap-and-trade in the budget resolution (even though he didn’t rule out the option entirely, either).

A number of Republicans have been particularly vocal in opposing a cap-and-trade provision in the budget bill, including the minority members of the Senate Environment and Public Works Committee, who called cap-and-trade a “risky, ill defined new energy tax” in a letter to colleagues on Thursday

“The budget resolution is not the right place for the careful bipartisan dialogue we need to get these issues straight, or to account fully for the legitimate concerns of energy consumers, economists, and industry,” the Republicans on the committee wrote. “While the budget resolution the Senate will debate is not yet available, we will offer an amendment to strip any climate revenue provision it contains.”

Some Democrats don’t like the idea either. Eight centrist Dems joined 25 Republicans in sending a letter on March 12 to leaders of the Budget Committee condemning the possible move.

“We oppose using the budget process to expedite passage of climate legislation,” they wrote. “Enactment of a cap-and-trade regime is likely to influence nearly every feature of the U.S. economy. Legislation so far-reaching should be fully vetted and given appropriate time for debate, something the budget reconciliation process does not allow.”

With or without cap-and-trade, the budget will be a highly contentious issue over the next few weeks. Obama is set to promote his budget plan to the nation on Tuesday night in a prime-time address, and he’ll continue talking it up at smaller events, while Congress works to hammer out its own version.