CALGARY -- Governments needs to set a clear vision on energy goals and then let private enterprise figure out how to get there, according to the chief executives of two major North American energy companies.

Greg Abel, head of Berkshire Hathaway Energy, and Doug Suttles, CEO of Encana Corp., were speaking at a Chamber of Commerce event in Calgary.

Both are looking to see what kind of targets will emerge in Alberta and elsewhere as governments become more proactive in tackling carbon emissions.

But they said policy-makers need to balance environmental concerns with reliability and affordability, and not tell companies how to achieve the targets.

"One of the roles government does have is set these long-term objectives. I think sometimes where they miss the mark is when they decide how," said Suttles. "Picking winners is difficult."

"I think that's absolutely critical," agreed Abel, "they shouldn't define the how."

Abel said the U.S. Environmental Protection Agency has provided a lot of flexibility within four building blocks of achieving carbon reductions, but that some aspects are still too prescriptive.

"Make these less prescriptive, let the people in the industry, the people that know their customers, figure out these answers," said Abel. "And give us a little more flexibility around this, and we'll get to great answers."

Suttles said that once government sets its targets it should help remove barriers.

"I think the next role of government is to help those organizations that have effectively been empowered to go do it, to help implement it, and to not find another roadblock," said Suttles, "They actually have to help take those roadblocks down."

Abel said that while private enterprise needs flexibility, for renewable energy to succeed it will require government incentives and technological breakthroughs.

"If you look at solar, the reality is it can't be done without incentives," said Abel. "They still need a substantial breakthrough in battery technology."

Suttles said North America has an almost unlimited supply of low cost natural gas, which he said was a big reason the United States has been able to return to 1990 carbon emission levels.

He said he expects gas prices to stay within the range of US$3.50 to US$4.50 per thousand cubic feet in the next decade because there is so much low cost supply.