You’ve heard the saying over and over, and you’ve seen the signs in yards, on business windows and bumper stickers across Craig, “Coal, it keeps the light on.”

That’s exactly what Craig Station does day in and day out — it generates low-cost electricity to provide continuous electricity to a vast region in four states.

The coal-fired power plant has a huge presence in the Craig and Moffat County community.

About Craig Station and Craig’s electricity

Craig Station employs over 300 workers and is operated by Westminster-based Tri-State Generation and Transmission Association, Inc. It paid nearly $36.7 million to its workforce in Northwest Colorado in 2013.

The company is a wholesale electric power supplier that is owned by 44-electric cooperatives, and it dispenses electricity to 250,000 square miles in Colorado, Nebraska, New Mexico and Wyoming.

Although it produces electricity for parts of Colorado, the city of Craig receives its power mainly from Craig Station’s neighboring power plant, Hayden Station.

Yet, when you look at the big picture of the electric grid, where the electricity comes from is irrelevant as long as consumers are able to “turn the lights on.”

How much electricity is generated is based on a demand and supply model. The supply of electricity that is put on the grid depends solely on how much demand is created by energy consumers that day, said Tim Osborn, operations superintendent at Craig Station.

Tri-state owns nearly 5,300 miles of power lines through which its power plants, wind and solar farms deliver electricity. The company’s eight power stations work together to either raise or lower the amount of electricity put onto the grid in order to meet the needs of its coop members at any given time. Once on the grid, electricity flows to where it is needed.

“If you can picture a sprinkler system in your yard, and the electricity is the water and you turn all of your sprinklers on, all of that (water) will go out of those sprinklers,” Osborn said. “And then one zone gets flooded out and doesn’t need (water) anymore, that zone can be shut off.”

It’s the same with electricity. When that light switch comes on, the electricity goes through, and when it’s shut off, the electricity flows to the next source.

“After our peak time of day, at 10 or 11 p.m., somewhere in there, people turn their lights out, depending on the time of year, air conditioners get turned off… so the peak can fluctuate a little bit and that’s the demand,” Osborn said.

The reason why the power plants need to work together to supply the demand is because megawatt energy can’t be stored.

“You can’t just store this volume of energy in a battery because one megawatt is 10,000 100-watt light bulbs, if you can picture that,” Osborn said.

Coal-fired power plants and renewables

Coal-fired power plants can constantly fill that need for electricity, something that renewable forms of energy cannot, Osborn said. Power plants can produce energy 24 hours a day, 7 days a week.

Wind and solar energy, on the other hand, only operate when the sun is out or when the wind is blowing. When clouds block the sun or it’s nighttime, energy can’t be produced.

“If you want to have any sort of reliability on wind or solar you have to at least have gas or coal backing it up,” noted Drew Kramer, public affairs manager for Tri-State.

Tri-State isn’t foreign to the renewable energy option though, as the company has the 30-megawatt Cimarron Solar Facility in northeastern New Mexico, meeting the “equivalent needs of 9,000 average homes,” according to the company.

Wind power is also in Tri-State’s energy portfolio. It operates the 51-megawatt Kit Carson Windpower Project in east-central Colorado, providing roughly enough energy to power 14,000 homes.

The company also has a 67-megawatt wind farm in northeastern Colorado called the Colorado Highlands Wind project, which can power nearly 20,000 homes.

“Additionally, Tri-State continues to be one of the region’s principal buyers of federal hydropower,” according to the company.

How electricity is produced at Craig Station

In order to produce that electricity at a power plant, coal — that’s provided to Craig Station from Colowyo and Trapper mines — needs to be pulverized, heated, generated into energy and released onto the grid.

Essentially, coal is burned in massive furnaces inside the plant, which produces heat. That heat is used to boil water, which produces steam. The steam is then used to turn the turbines, which produces electricity.

The power plant has three units that carry out this process, recognizable by the three tall stacks that thrust high into the air called Unit 1, Unit 2 and Unit 3.

Unit 1 and 2 have wet scrubbers that reduce the amount of sulfur dioxide that’s released into the atmosphere during the coal burning process.

“The combustion byproduct (of coal) is sulfur dioxide, which is SO2,” said Rich Thomson, maintenance superintendent at Craig Station. The scrubbers take the flue gas and condition the byproduct with water.

The white plumes from Unit 1 and 2 that look like clear smoke are basically steam, or water vapor, he said.

Unless it’s extremely cold outside, no plume (water vapor) is apparent from Unit 3, because it has what is called a dry scrubber, which doesn’t use water.

“The technology that was put in on Unit 3 was at the time when there was a concern about the amount of water that was being used in the west. They wanted to reduce the amount of water usage, so they went for a dry scrubber technology on Unit 3,” Thompson said. “Both technologies (wet and dry scrubbers) are considered best achievable control technologies. The point is to get the sulfur dioxide out of the emissions.”

Craig Station takes water from the Yampa River and runs it through the power plant to produce steam to make electricity and to cool off big equipment — mainly the turbines.

“We condense the steam as it goes through the turbine and back into the water so we can use that condensed steam cycle again,” Osborn said. “We’re in a constant recycle process out here with the scrubbers and the river water.”

The power plant recycles 18 million gallons of water each month, and is allowed to take 45 cubic feet per second of water from the river each month.

The turbine, which is powered by the steam from Yampa River water, rotates 3,600 times every minute (3,600 rpm).

“The reason we have it rotating at that speed is our electric grid is based on 60 hertz electric power. The U.S. works on 60 hertz, so you basically take the square root of 3,600 and that’s 60,” Osborn highlighted.

New EPA rules could affect coal-fired power plant business

Craig Station upgraded to a newer, faster turbine in 2008.

“What we have done here starting in 2008 is put a better turbine in so that the steam flow through the turbine is more efficient,” Osborn said. “So we can actually burn the same amount of fuel and have more output.”

That essentially lowers the heat rate, something that the Environmental Protection Agency is asking coal-fired power plants to do in its Clean Power Plan proposal that was released by the Obama administration in June.

Such upgrades are what Tri-State is hoping the EPA will consider recognizing as it works to finalize its Clean Power Plan.

Comments on the proposed plan were originally due to the EPA by Oct. 16, but due to the hundreds of thousands of responses to the proposal, the EPA extended the deadline to Dec. 1.

Once the plan is finalized, it will set standards on how much carbon emissions coal-fired power plants can release into the air, along with other standards.

Tri-State calls itself a compliant company, meaning it makes proper upgrades to meet standards handed down by the state and federal government.

The EPA visited Craig in September to hear from coal miners and power plant workers about how its proposal could harm the local economy.

Tri-State’s primary concern is it wants the EPA to count the $176 million in upgrades it has already made to Units 1, 2 and 3’s turbines.

“We did Unit 3 in 2008, in 2011 we did Unit 1 and did Unit 2 in 2013,” Osborn said.

Only time will tell what will happen with the EPA plan, and the energy industry should have a good idea of what’s next in the coming year.

Contact Noelle Leavitt Riley at 970-875-1790 or nriley@craigdailypress.com.