Clean energy and environmental groups are asking the state to update the way it accounts for the environmental and health costs of generating electricity.
Current estimates used are no longer accurate and don't reflect changes in the science and economics of power generation, said University of Minnesota economist Stephen Polasky.
In the mid-1990s, the Public Utilities Commission began to calculate what economists call the "external costs" — damages — caused by electricity generation. They include pollutants that contribute to asthma, heart and lung disease, and greenhouse gases that contribute to global warming.
The commission uses those dollar values when it considers utilities' plans to build new power plants. Environmental groups, though, say the values are now outdated.
Polasky says the state currently assigns a value of zero to $4 per ton of carbon dioxide emissions. He says a more accurate number would be $38 per ton.
"External costs are in fact real costs," he said. "They should be reflected when the PUC is thinking about alternative forms of energy production..."
A more realistic accounting would encourage energy efficiency and renewable sources, said Beth Goodpaster, clean energy program director with the Minnesota Center for Environmental Advocacy.
The Public Utilities Commission will take input from utilities and others before deciding whether to review the matter.