What do Power Plants do at Night?

[dontsendbubbamail]

You generally have two peaks a day for electric demand. One is in the morning when everybody gets up and the other is when they get home from work. This gives you a demand graph with a line that has two humps around 7:00 AM and 6:00PM. The area under the line is your electric demand. There is always demand for electric power. Nukes and large base load coal plants are designed to run wot and supply this constant need. The rest of the area under the graph is filled in by smaller coal fired, combustion turbines (jet engines), and then hydro in that order. Hydro is managing the tip of the peak, because it can be brought on and off line the fastest and with the lowest cost. For the small coal fired plants, it cost money to start it up, so the longer you can run it per start the better. Using plants to run the pumps of a pumped storage hydro units is a more cost effect use of the plant. At least that is basically how it is done down South USA.

Bubba

 

[Heynow999]

I am dragging up this old thread because it came up in a Google search and I thought I might be able to add to it

I sell solar panels so I get to talk to a lot of people about electricity. I was in a Home Depot in Ontario, Canada doing a little sales presentation and it happened to be near the nuclear power plant east of Toronto. I talked to many people that day who worked in the power plant. One guy in particular I talked to for at least 1/2 an hour worked in the control room of the plant. He explained to me how there are many levels of generators from the baseload nuclear plant to stand-by natural gas generators. Some, like nuclear, run full out 24/7. Some, like the natural gas plants, are standby that can be fired up in a few minutes. It is all done by phone (at least at the Pickering plant) No computerised smart grid. As the demand rises during the day, the phone rings and some tells the control room to "throw some more coal on the fire" and make more electricity.

So about nuclear and ground rods, he said that that is indeed what they do with excess power during the night. It is just sent back into the ground! Even more bizzare is there is a large wind turbine near the nuclear plant. I guess they want to "look" green. But the dirty little secret is they will spin the windmill backwards to burn of excess energy when they need to. I know people who say they see the wind turbine spinning on calm nights! The hourly spot rate for electricity regularly goes negative in Ontario, which means they will pay you to use electricity! It happened 6 times in October 2009

http://reports.ieso.ca/public/DispUnconsHOEP/PUB_DispUnconsHOEP_20091115_v24.xml

 

[gilnet]

good reading! I ain't schooled on the particulars.I know there are some "crazy farmers" up here that are developing supercaps,actually sell them that have something to do w/nic/zinc.for storing windpower. The whole grid infrastructure fight between the big boys as to how to store power has already started (pie pieces)We buy cheap electric from Canada Off peak(minn,wi.)And Dog! sucking water out of the big muddy on the scale you talk of would suck our water table to zip.Ask Canadians about the Garrison Project.The second garrison project was called an act of war (80's) they were going to divert enough to give the swest corn crops like ours,more golf courses vegas neon and lets not forget,even with Hoover dam diversion L.A.(and the rest of Cal.)would take all they can get.Great Lakes have been in decline(largest source of fresh water in the world)and have all of canada and border states scrambling to stopU.S.politicians from trying to get the water out west where the money is.Old Timers up here told me growing up that Water will cause a war in my liftime.Don't want that one panning out.Old and paranoid in the North.

 

[thomas]

This is why we want electric cars that can charge at night and also be used as one huge battery on the grid. If you have your car plugged in during high demand times you can sell to the grid.

Heres a page that shows the actual power use and import/export of electricity in Denmark. Its in danish but I think you get the idea

http://www.energinet.dk/Integrationer/ElOest/ElsystemetLigeNu/energinet1.swf