A truck delivers coal to Pacificorp's 1440 megawatt coal fired power plant on October 9, 2017 in Castle Dale, Utah. Getty Images

The Trump and Obama administrations have at least one thing in common when it comes to energy policy: Both have kept power plant owners in the dark about greenhouse gas rules. The Environmental Protection Agency this week proposed repealing the Clean Power Plan, President Barack Obama's signature effort to reduce greenhouse gas emissions from American power plants. The agency said it would begin a new rule-making process, but some analysts say electric utilities are unlikely to get any clarity in the coming years. The drastic swing — from prioritizing the fight against climate change under Obama to protecting the coal industry under President Donald Trump — marks a break from the past, when power plants could typically expect more moderate policy shifts between administrations.

To the extent government is not giving those clear signals, I consider that a substantial regulatory failure. David Littell Regulatory Assistance Project principal

Democrats and Republicans "both seemed to have decided that their regulatory agenda is more important than certainty for businesses," said James Coleman, professor of energy law at Southern Methodist University Law School. "What certainty means is that you don't have drastic changes between administrations," he told CNBC. "I don't think either administration has really prioritized that." Power plant owners know that some sort of regulation is coming. A Supreme Court ruling that carbon dioxide and several other greenhouse gases qualify as pollutants, followed by EPA's finding that those gases are a public health concern, means the agency is required to regulate them.

Harder to make investments without rules

Under Obama's plan, the EPA set emissions targets for states but left them to figure out how to achieve them. The Supreme Court put the rule on hold in 2016 after 27 states and other stakeholders sued. The D.C. Circuit Court has kept it in limbo while the new administration plotted a new course. Current EPA Administrator Scott Pruitt, a climate-change skeptic, asserts that Obama's plan will force power plant owners to shut coal-fired facilities and invest in natural gas and renewable power. He argues that exceeds EPA's authority and has floated a regulatory framework more accommodating to coal plant owners.

However, EPA's repeal process will likely last throughout much of Trump's first term, and it's likely to face legal challenges from environmentalists and attorneys general in liberal-leaning states. It could also be overturned if a Democrat wins the presidency in 2021. That means utilities must continue to make investments in the facilities that generate America's power with little certainty on future regulations. "With uncertainty, the investors and the markets ... can't fully assess the wisdom of certain planning decisions and certain investment decisions. It increases investor uncertainty," said David Littell, principal at the Regulatory Assistance Project, a nonprofit that promotes clean and efficient energy. Littell, a former commissioner for the Maine Public Utilities Commission, says a big part of his role as a state regulator was creating clear rules so businesses can do their job. "To the extent government is not giving those clear signals, I consider that a substantial regulatory failure," he said. Despite legal efforts to salvage the Clean Power Plan, utilities can safely assume it will not survive as a whole, said Philip Wallach, a senior fellow at the liberal-leaning Brookings Institution. Wallach, who correctly predicted the DC Circuit Court would not issue an opinion on the Clean Power Plan, said the courts are not likely to push forward an Obama-era policy opposed by the current administration.

Little certainty coming from Trump