Skip to comments.Surplus Renewable Energy: An Update
Posted on 02/10/2012 1:06:41 AM PST by neverdem
Last year I wrote about sudden surges in renewable energy that set up a conflict between wind producers in the Pacific Northwest and the Bonneville Power Administration, a federal agency that runs hydroelectric dams and the regional grid. When unseasonable storms created a simultaneous surplus of wind and water, Bonneville gave free power away but still had to deal with an oversupply that could overwhelm the grid.
Eventually it resorted to unplugging the wind machines because routing excess water around its dams could create excess bubbles in the river...
Another would be using batteries, the secretary of energy said. The problem is that at the moment, the batteries needed to store just one kilowatt-hour (the amount needed to run an window air conditioner for an hour) cost about $350.
That is steep, given that the average price of that amount of energy is about 11 cents. But at $100, Dr. Chu said, batteries would go viral and change the energy equation.
But there are simpler solutions, the secretary said. He said he recently visited a medical center in Houston that ran a power plant that produced both electricity and steam and could run at very high efficiency when both were needed. The problem, Dr. Chu said, is that at some hours, especially at night, there was not much need for the steam. So the medical center was using it to run a cooling device that was usually a component of an air-conditioning system.
In this case, it was simply chilling water in a tank that could be used to cool the building the next day. The amount of energy needed to keep that tank cold is one-tenth of what youd need to chill it, he said, describing a method of storing energy as cold water instead of as electricity...
(Excerpt) Read more at green.blogs.nytimes.com ...
I'm not sure how that is progressing.
Bath County, Virginia has a peak-load generation facility in the Back Creek Valley, but I think the power to pump water from the lower valley to the upper one is from conventional sources and done in off-peak hours. Water running through tunnels in the mountain from the upper valley to the reservoir in the lower valley generates electricity during peak hours.
Oconee Nuclear Plant in South Carolina sits on the shore of Lake Keowee, a reservoir formed by a hydro-electric dam built in 1971 on the Keowee River, a tributary of the Savannah River. The Keowee dam generates 158 megawatts of electricity and the waters of the lake cool the reactors at Oconee Nuclear.
In 1973, Jocassee Hydro-electric dam was build immediately upstream of Lake Keowee. At night, surplus power from Oconee’s Nuclear three nuclear reactors was used to pump water from Lake Keowee UP to Lake Jocassee. During the day and times of peak demand, the water returns to Lake Keowee through Jocassees turbines, generating 610 megawatts of power in the process.
After Oconee’s third 846 megawatt reactor came on line in 1974, there was more surplus power at night than could easily be stored in Lake Jocassee. Bad Creek Hydroelectric Station was built in 1991 to handle this surplus.
Lake Jocassee sits 210 feet above Lake Keowee. The Bad Creek reservoir sits 1,200 feet above Lake Jocassee, up on the Blue Wall that forms the border of North Carolina and South Carolina. Four 250 megawatt centrifugal pumps with 8 foot diameter intakes are buried 1/4 mile inside a mountain on the upper reaches of Lake Jocassee. At night water from Lake Jocassee is pushed by these pumps up 1,300 feet (the pumps sit well below the surface level of Lake Jocassee) into Bad Creek’s 385 acre pond. During time of peak demand, the water flows bad down through the pumps, generating up to 330 megawatts per turbine at ‘full pond”.
Lake Jocassee and Bad Creek Hydroelectric Station.
Gravity Batteries....BIG batteries!
BTW, as of 2008, Oconee Nuclear had generated over 500 million megawatt hours of power and is “the first nuclear station in the United States to achieve this milestone.”
What’s the cost of power for folks there?
With hydro power, you build reservoirs behind your power-producing dams. That's how you store all that runoff during the big snow melts and rainy seasons.
What to do with all that excess wind energy?
Balloons. Big, big, balloons. Let the unused wind fill 'em up, and then when the wind dies down, open their necks in front of the windmills. Problem solved.
Next, I'm working on mirrored thermos bottles to capture excess sunlight.
All of these energy storage schemes have one problem...entropy. Whenever you change one form of energy to another there are energy losses. Using a windmill to compress air produces heat energy that would be lost. Using the compressed air to turn turbines and make electricity also has a loss of energy. The windmills themselves are very inefficient at producing energy...theoretically only about 30% of the energy in the wind can ever be captured. The result is that you might create a Rube Goldberg device that could store wind energy and make some electricity in the end but it would be ridiculously inefficient and thus make that electricity very costly to produce. The cost of electricity produced by windmills alone is many times higher per kilowatt than electricity produced by modern coal plants or nuclear plants. Sure with billions of dollars of our tax money you might demonstrate that this idea could work,but it would never be practical or cost efficient.
About 150.00 for a month for a 4,000 square foot home.
The point of these energy storage methods is to do something productive with over production. It may not be efficient, but these only other choice is to waste all of that energy.
Near as I can tell,
Industrial ~ $0.055 kwh,
Commercial ~ $0.07 kwh
Residential ~ $0.09 kwh
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Do you realize that if I created a cube that spurt out reliable, cheap, energy with no pollution the left would NOT be happy.
They don’t want ‘clean’ energy. They want less energy. They want government controlled energy.
>>But there are simpler solutions, the secretary said. He said he recently visited a medical center in Houston that ran a power plant that produced both electricity and steam and could run at very high efficiency when both were needed.
We’ve been doing what are called “cogeneration systems” for at least 30-40 years. The problem is that there are only so many places that need a ton of process heat, and then you are back to just doing regular ole’ electrical generation.
For Chu to be touting this as if it is something really cool and new is just absurd.
And you’ve nailed it - kill the subsidies.
Thanks for the ping!
Locally we have a large plant that generates it’s own electricity with big coal fired generators (that are scrubbed and rescrubbed). The boilers produce high pressure steam downstream from the generators. That steam is piped all over the plant for process heat has been for decades.
In Saudi Arabia they produce water by condensing steam from salt water after it turns the generators to produce electricity. The steam is produced i gas fired boilers. The louts in California could do the same but would rather writhe in misery and do without.
Ditto Raccoon Mountain pumped storage at Chattanooga Tennessee that stores the water pumped by the power from the Sequoyah Nuclear Plant.
I was fortunate enough to have worked at Oconee Nuclear during a refueling outage. Ending up working inside the containment building (big concrete dome).
Also worked at Bad Creek on the powerhouse construction. I got to clean out INSIDE the centrifugal turbine, making sure that all the construction trash was out before putting it into service. "http://en.wikipedia.org/wiki/Francis_pump_turbine"
Also helped to install the 8 foot diameter ball valves which control the flow.
The powerhouse is 1/4 mile inside the mountain and is in a cavern about 7 stories tall. Very interesting job!
Lake Jocassee looks like a fjord - very clear water! The SC state record Spotted Bass, Red-eye Bass, Smallmouth Bass, Brown Trout and Rainbow Trout were all caught at Jocassee.
Your namesake would be proud of you.
Here is my work....... the glass and aluminum curtain wall enclosing the turbine room at both Watts Bar and Sequoyah.
The 24' free standing bronze aluminum and glass curtain wall is below the lettering and the blue sheet metal. Both are dwarfed by the cooling tower that always attracts pictures and are thought to be the actual nuclear plant by many.
. Unlike most nuclear plants that are utilitarian, TVA wanted a show place and spruces the turbine rooms up with the high free standing curtain walls.
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