LAKE OZARK, Mo. - Ameren Missouri is replacing four aging transformers at Bagnell Dam with new environmentally safe models that have never before been used in North America.
The new transformers, which cost about $4 million each, are powered with a special type of gas that is not only safer for the environment, but is also safer for those who live, work and play at Lake of the Ozarks.
"The old transformers were powered with oil, which is of course explosive. And if a leak occurred, it could cause environmental problems for the Lake, the (Osage) river and the surrounding land," said Alan Sullivan, consulting engineer for Ameren Missouri. "But, what could be even more important is that the gas transformers are non-explosive so the physical danger to those who live, work and play near the dam will be vastly reduced."
The transformers, which are manufactured at only one location in the world, have never before been used in North America and are, in fact, rarely used in countries outside Asia largely because most other countries with large dams have much sparser populations, Sullivan said.
Ameren Missouri's long-term plan calls for all four oil-powered transformers at Bagnell Dam to be replaced with the gas-powered giants. But because of the cost and the extensive workload required by the installation, the work is being done over time.
"This is the third one to be installed," Sullivan said. "And the installation of the final one will take place sometime in the next few years, depending on budget."
The transformers, which are manufactured at the Mitsubishi Plant in Tokyo, Japan, were shipped here in pieces and assembled on site by workers with Bagnell Dam's maintenance crew. It takes about a month to put the gigantic machines together and get them up and working once they arrive on site. But, Sullivan said, the workers who are doing the job have some expert help.
"When we installed the first one, we had the expertise of four engineers from Japan on hand to supervise," Sullivan said. "Now that we are on the third one, we only need the help of one of those engineers. But he stays here and helps us through the entire installation process until the transformer is up and running."
The idea for using the gas-powered transformer was brought to Ameren Missouri by James Lueckenoff, Bagnell Dam production supervisor and engineer.
Lueckenoff used to work at Ameren Missouri's Callaway Plant near Fulton, but transferred to Bagnell Dam seven years ago.
He said he got the idea for using the gas-powered transformers from an engineer who told him how they were being used throughout Asia.
"When it became obvious that we were going to have to replace the old transformers, I took the idea for using the gas transformers to the company," Lueckenoff said. "It took some research by our top officials and a trip to Japan to actually see the transformers at work before the company decided to go ahead with the change."
Unlike most transformers used at hydroelectric plants in North America, the giants being installed at Bagnell Dam are not powered by either oil or coal, but by a noncombustible gas called SF6.
Sullivan said although the old transformers were not responsible for causing any environmental or safety problems at the dam, over the past few years regularly scheduled maintenance and safety testing did show that they were beginning to deteriorate internally and needed to be replaced.
"The old transformers were the originals that were installed in 1931 when the dam was built," Sullivan said. "Although they had done the job for all these years, and our crews kept them in good shape, it was becoming obvious that they needed to be updated and the decision for replacing them with the gas-powered ones was both more environmentally responsible and safer for both our workers and the public at large."
The dam's transformers are used to increase the voltage of the electricity generated by the hydroelectric plant before it is sent out on the grid. Sullivan said when they are all up and running the four generators will take the 14,000 volts of electricity put out by the dam's generators and "ramp it up" to some 140,000 volts before sending it out on the grid.
"These new generators will give us the opportunity to generate more electricity at a faster pace and at a much safer rate than ever before," Sullivan said.
The "gas tank" portion of the new transformers are so large that they are brought to the U.S. by ship, then placed on an "over-sized semi-type truck," hauled to Bagnell Dam and lifted into place by a crane. The remaining sections of the transformers were also transported by ship from Japan, then hauled to the dam by a "fleet of 18-wheelers" where they were assembled by Ameren Missouri workers who work three shifts per day, six days per week until the job is completed.