H2O Equals Power
Growing up, many of us can remember the story of Jonah being swallowed by a whale. In our minds, we most likely envisioned Jonah standing inside the great whale looking for a way out. At least, that is the way pictures and cartoons showed it must have been like inside of such a large creature.
I will have to admit that early visions of Jonah entered my mind as I first entered the draft tube at the New Martinsville Hydroelectric Plant. The size of the tube that lies below the river’s water level is something impressive to experience. The faint smell of the river lingered in the moving air currents as the sound of my footsteps echoed off the walls. Approaching the massive runner blade was impressive in this place few ever imagined existed. I had seen the outside of the draft tube and did not realize the shear internal size until I stood before the blade.
One of the first industrialized sources of power in this country was water. Early industries understood the flowing water had weight and mass. If you could control the water and direct its force into mechanical energy, the possibilities could be endless. That discovery long ago is why the Ohio River is so important to the power plant.
We have come a long ways since those days, but the use of water to produce hydrodynamic force and be changed into energy is very much alive today along Howard Jeffers Drive. The hydroelectric plant has been part of our community for over 23 years and plant manager Chuck Stora has been there since the beginning. Chuck was hired as an operator at the plant, leaving a job in a coal mine. Over time he worked through the rigorous training program to understand the many complexities of the power plant’s operation. Back then, same as now, each employee goes through a four-year training program to operate the plant. In addition to being an operator, each may have additional job knowledge, such as electrical and mechanical skills. Stora’s personal training paid off and in 1995 he earned the plant manager’s position.
A short time ago, I was Chuck’s guest to visit the plant during a shutdown of its number one power generator and draft tube. The opportunity to visit the plant and get a chance to see inside the unit sparked my curiosity. I had visited the plant some years ago, while both the plants units were in operation. The plant’s concrete structure we see from the outside gives no indications of the facilities inside design and size. The plant from top to bottom stands 80 feet. That is the same as an eight story building, except it is all below your feet at ground level. The power plant structure is constructed mostly underwater when standing on the outside of the complex.
On the inside it is well lit, clean, brightly painted, and well kept. As you descend down each level you drop further into the operating structure. Electrical cabinets, pumps and a variety of equipment are in place on each level as you venture downward. Not long after entering and beginning your descent, you realize the walls around you are holding back the Ohio River.
Each of the two units begins operations by allowing water into the draft tube through wicket gates on the upriver side. The gates open much like the shutter on a camera. A total of 16 gates open as a connecting ring around the outside of the draft tube moves each gate simultaneously. The ring moves on two-inch ball bearings. It takes a total of 502 of them to operate the ring smoothly. Improving the ring’s operations was the primary reason the unit was out of service. During repairs the ring underwent a design change; when completed a new roller style bearings will be in place. This will keep the unit running smoothly for many years to come.
The plant was constructed for a cost of $130 million when built in the late-1980’s. Each of the plant’s two generating units can produce up to 18.8 megawatts of power. In order to produce that power, 14,000 cubic feet of water must pass over each of the runner blades which turn the power generators. If you had a swimming pool in your back yard the size of a football field 10 feet deep, the water passing through the plant would fill it in 10 seconds. When originally built it was one of the largest bulb-type turbines in the world.
The turbine design for the plant is called a Kaplan Blade. The blade is 25 feet high and made of stainless steel. The blade and its supporting structure weighs in at nearly 100 tons. In comparison, the largest blade on the Titanic was 23 feet high and weighed in at just 38 tons. When in operation, the blade speed is controlled by a hydraulic governor to maintain 64.3 rpm. The runner blade turns the armature inside the generator to the same speed. Two large servo motors control the operating ring to the wicket gates and the pitch of the runner blade. This maintains the power out of the generator at a constant 6,900 volts which is in turn stepped up to 138,000 volts before going onto the power grid.
In comparison to a steam-powered generator that turns at 3,600 revolutions per minute, the hydro generator seems slow in compassion at only 64.3 rpms. A steam generator has two connecting poles from its generator windings, where as the slow turning hydro turbine has 112 connecting poles. Both generate power, but the hydro generator does it at a much slower speed.
There is one other important difference with hydro power. A smaller steam powered generator may use up to 350 tons of coal a day. The hydro plant simply opens the wicket gates and allows the water to pass over the turbine blade on its downriver journey. Worldwide, nearly 20 percent of power is generated by water. In our country it is near six percent, but the number is growing as renewable energy technology improves. At present, five hydroelectric plants produce power along the Ohio River. Several more are in some stage of planning or construction.
Why renewable? The same Ohio Rivers waters flowing from its beginning at the point in Pittsburgh will pass through each of the five plants on its way to the Mississippi. At the two rivers’ junction a fisherman may catch a flathead catfish in the same waters. not realizing its down river journey produced electric for homes along its way.
The New Martinsville Hydroelectric Plant is part of our nation’s power grid that makes all our lives better. It plays a small part in power generation for our country, but it takes all the resources of coal, natural gas, nuclear, winds, tidal, and hydro to keep the lights on. America has come a long way since the first water wheel generated power to begin building our country. Chuck Stora and his team are helping to carry on that tradition as I see it Thru the Lens.