Speakers from an overflow crowd lined up Thursday night to blast Duke Energy for relying on coal and nuclear power while investing comparatively little in energy efficiency and renewable energy.

The N.C. Utilities Commission scheduled the Charlotte hearing on the 20-year growth plans filed every other year by Duke Energy Carolinas, which serves Charlotte, and other North Carolina utilities. The plans project future demand for electricity and how the utilities will meet it.

Duke Carolinas’ most recent plan comes as the utility is transitioning away from coal toward cheaper, cleaner-burning natural gas. The plan forecasts a 45 percent drop in coal use by 2032 and an 86 percent increase in natural gas.

Nuclear generation stays about the same, supplying half of the utility’s energy production. But while renewable energy such as solar and wind grows fast, it still reaches only 3 percent of Duke’s power generation in 20 years.

That’s not good enough for those who believe climate change – coal is a major producer of greenhouse gases — is near a turning point and who blame water and air pollution on power plants they say are obsolete.

“We need a radical plan right now to abandon fossil fuels, but Duke’s plan falls far short,” Sally Kneidel, a Charlotte biologist, told the commission. “Catastrophic climate change is upon us. Duke Energy is one entity that could do something about it. And you are too.”

Charlotte resident Harry Taylor said, “Duke Energy is rewarded for building (power plants) whether or not there’s need, and without risk. The (plan) suggests that even though they know better, they’re going to keep doing the same thing for the next 20 years.”

Anna Behnke, 12, toted to the podium her science project. She said it found arsenic in water near her home close to the Riverbend power plant west of Charlotte. “Duke could set an example,” she said, “and you could make them do it.”

Duke Carolinas points out that it is changing. The utility is retiring 38 old coal and oil-fueled power plant units, and has or will soon open one new coal-fired plant and two gas-fired plants that will operate far more cleanly.

“The challenge of our job is to balance those concerns with the costs to our customers,” said Jeff Brooks, a Duke spokesman.

Bill Gupton, outreach director for Consumers Against Rate Hikes, said Duke could do far more with energy efficiency, paring its emissions while saving consumers money. The 14-group coalition is fighting a 9.7 percent rate hike Duke Carolinas is seeking.

“We could avoid building several new power plants, keeping our rates below others in the region” with efficiency, he said.