Plant Tour Highlights Efficiency Gains For HEA
A new addition to the Homer Electric Association’s power generation portfolio is set to go online by the end of the year. The Nikiski Combined Cycle Conversion Project is a steam turbine, fueled by the excess heat generated by an existing natural gas turbine.
I was joined by nine others Wednesday afternoon for the tour. We left the old Agrium plant in Nikiski for a short drive next door to HEA’s new steam turbine. It’s part of the co-op’s Independent Light Program, where HEA will generate all of its own electricity beginning in 2014. That’s when its current contract with Chugach Electric is done.
We were greeted by Brad Zubeck, HEA’s Independent Light Project Manager, who told us the combustion turbine at this site came from Soldotna, where it generated both power and waste heat that went to Agrium.
After the Agrium plant shut down in 2007, the heat generated by the natural gas turbine went to waste, essentially. By itself, that turbine cranks out 40 megawatts. The new steam turbine will kick that up to about 60 megawatts. A little more natural gas, and the total output is 80 megawatts. The plant just outside Soldotna that’s currently under construction will serve as back up.
We made a quick stop by the control room where the 12 operators, five shift supervisors and the plant manager will keep an eye one things, then moved into a big room that’s home to a gas turbine.
“Without firing any additional gas, so for the same gas the we burn through this unit, we’re able to pick up 18 megawatts from our steam turbine. That’s about a 45 percent increase in efficiency,” Zubeck said.
Back outside for a quick look at the boiler that captures the steam and sends it on the turbine, then on to the building where all that steam ends up.
“The boiler sends steam to the steam turbine to move that unit. (Then we) send it over to a big radiator, like in your car, and it takes that steam and makes it water again, and we pump it back over to this boiler to make it into steam again. So it’s a closed loop system and we recycle that water.”
Working in concert with HEA’s share of the Bradley Lake Hydro plant, this site in Nikiski will cover all the power needs for HEA. That comes out to a little more than 80 megawatts during peak usage in the winter and about 73 megawatts during peak usage in the summer.
This was the first time HEA had opened its doors for a tour to the public. After all the tours, Board of Director election results were announced at the annual meeting. Dan Chay of Kenai won the seat for District one, Ed Oberts of Soldotna will represent District two and Bill Fry of Homer remains in the seat for District three.