Too much green energy at night. Turn them off or pay high fees.

[Desertdog]

There doesn't seem to be a problem here now, but if they can do it there, then they will be able to do it here.  Produce too much Green Energy and pay the piper.

Too much green energy at night
Wind turbines seem to be producing too much energy at times when there is enough electricity.
http://politiken.dk/newsinenglish/article658546.ece

Danish wind turbines are now producing so much energy that they may have to be stopped at night in order to avoid excess production duties.

In October, turbine owners will have to pay an excess production duty of DKK 1.70 for each kilowatt of energy produced during evenings and nights when there is too much electricity on the market.

“The last thing that we want to do is to stop a wind turbine. But we may have to. No-one wants to produce at a loss,” says Wind Energy Denmark Director Niels Dupont who administers a third of the wind energy production in Denmark.

Energinet.dk, which administers the Danish electricity network says that periods with too much electricity in the network will rise from 100 hours per year to up to 500 hours.

“When prices go negative, wind turbines will probably have equipment installed so that you can reduce production,” Marketing Manager Nicolaj Nørgaard Petersen tells Jyllands-Posten.


Edited by Julian Isherwood

[Headless Thompson Gunner]

Heh!

[TMM]

great way to encourage green energy, huh?

tmm

[HankB]

Another instance that proves the validity of my .sig file.

[AZRedhawk44]

Isn't all the EU linked on powergrids?

Turn down the juice on some of those French and German nukular plants, for pete's sake!

Really... why doesn't anyone ever consider poor pete?

Sheesh. :rolleyes:

[Leatherneck]

Aw C'mon, guys. This is serious!

Imagine a Danish wind machine cranking away all evening and into the night, pushing power into the grid, while all the Danes are doing the usual evening power-sucking activities--laundry, TV, PCs, outside and inside lights, etc. Then, one by one, the families start finisheing drying the clothes, the dishwasher finishes its dry cycle, the kids turn off the TV and PC and go to bed, turning lights off as they go (because that's been pumped relentlessly into their tiny little brains by the Greens).

The power usage drops slowly but the turbines spin happily on, and on, and on, and on. The power, having no place to go, starts swelling the lines. Slowly but steadily the lines swell and swell, until about two ayem:








ZOT!   

TC

[Firethorn]

Couldn't they help with this by encouraging electric heating(whether heatpump or not) with substantial thermal mass storage combined with demand based pricing?

There's around 8760 hours in the year.  A little above 1% of the time is overproduction, and they're looking at it approaching 6%.

[AZRedhawk44]

Couldn't they help with this by encouraging electric heating(whether heatpump or not) with substantial thermal mass storage combined with demand based pricing?

There's around 8760 hours in the year.  A little above 1% of the time is overproduction, and they're looking at it approaching 6%.

Encourage consumption!!!??!!!

Are you completely mad?

[Firethorn]

Encourage consumption!!!??!!!

Are you completely mad?

At the right time...   

The idea being that you need heat sometime, but if you have a 500 gallon hot water tank for building heat, or even a 2 ton furnace or whatever, you can actually be pretty picky on WHEN you need the heat.  Thus, during those nights when the wind is blowing good, all those heaters kick on and use the power.

You could use the same system with cooling, just get a mass cold instead of hot.

[Gewehr98]

What?

They thought the wind didn't blow at night when they put those turbines up?

Pump it into the grid, and spin flywheels, charge batteries, or something similar.

We're not seeing the whole story here, I'll wager.

[WeedWhacker]

They thought the wind didn't blow at night when they put those turbines up?

Pump it into the grid, and spin flywheels, charge batteries, or something similar.

We're not seeing the whole story here, I'll wager.

Therein lies the rub: production of electricity is fairly easy. Storage of electricity is not, and while definitely possible, is prohibitively expensive in almost all cases on the scale required of national production.

[mtnbkr]

How is turning off the windmills any different than reducing water flow across turbines in hydro plants or turning down the nuke heat in a nuclear plant?  Isn't it normal to reduce power generation during periods of low demand?

Chris

[Fly320s]

I need some schooling on electricity. What's wrong with excess electricity?

[Firethorn]

How is turning off the windmills any different than reducing water flow across turbines in hydro plants or turning down the nuke heat in a nuclear plant?

Hyrdo plants could almost be considered big batteries anyways, run them too fast and you run out of water to produce electricity.  They just refill on their own.  Turning down the heat in a nuclear plant costs efficiency, and given the cheapness of the fuel compared to the more or less static costs of running and debt service, it's best to run at 100% as much as possible.

Isn't it normal to reduce power generation during periods of low demand?

Windmills aren't built to be very good at throttling, they produce a certain amount of electricity at any given airspeed, or they're stopped.

I need some schooling on electricity. What's wrong with excess electricity?

Too much electricity translates out to too much voltage, things go overspeed and burn out quicker.  There are controls to prevent this, of course, but they're expensive as well.

[mtnbkr]

I need some schooling on electricity. What's wrong with excess electricity?

Storage and/or overload of the transport system.

Chris

[Gewehr98]

It's also why we have off-peak electric rates over here.

The practice encourages us to run our water heaters, clothes washers, dryers, and dishwashers after hours, keeping at least some load on the grid.

[Fly320s]

I guess that just opening the generator connector (taking the gen off-line) isnt feasable?

[Firethorn]

I guess that just opening the generator connector (taking the gen off-line) isnt feasable?

Then all that resistance the turbine is experiencing from the generator disappears and, discounting failsafes for that very purpose, the turbine overspeeds, and depending on the wind, can destroy itself.   Not likely today, they have all sorts of brakes, one of which would be to simply send the electricity across a big honken resister.  Then you stop the blade, because it takes quite a resister to take a 20kw all the way up to 6MW.  At the higher power levels, conventional brake pads are inadequate.

Of course, nuclear, solar and wind all share the same problem:  their main cost is in aquisition; fuel is either cheap enough to be nonconsequential or free.  It's not like shutting them off saves any fuel expenses.  Thus, they want to sell power whenever they're capable of producing it, to pay back their loans/investment.

[wingnutx]

Put all the excess energy into a bunch of flywheels for storage, or perhaps use it to produce hydrogen.

[Firethorn]

Put all the excess energy into a bunch of flywheels for storage, or perhaps use it to produce hydrogen.

Both cost quite a bit of money to set up.  Currently not worth it at 100 hours a year, even with penalties.

One interesting solution I saw was to set up turbines that don't have generators on them, just air compressors.  The compressed air is then used to power a turbine.  Benefit?  By the time you put all the pipe runs in, you have several hours of storage/power evening.  Combine with a salt cave or something even bigger to store the pressurized air and you can get days/weeks.

[Nick1911]

Both cost quite a bit of money to set up.  Currently not worth it at 100 hours a year, even with penalties.

One interesting solution I saw was to set up turbines that don't have generators on them, just air compressors.  The compressed air is then used to power a turbine.  Benefit?  By the time you put all the pipe runs in, you have several hours of storage/power evening.  Combine with a salt cave or something even bigger to store the pressurized air and you can get days/weeks.

I haven't run the numbers, but I've heard that compressed air is a miserable store of energy.

[Desertdog]

Prop driven aircraft have had adjustable props for many many years.   Put adjustabe props on the wind turbines where they can feather the props, or make them where they turn right angle away from the wind. 

Actually they probably have them that way now, the owners just don't want their generation ability to stop.

[cfabe]

Sounds to me like they just have too much generation capacity available now. The power company doesn't want it's plants sitting idle while privately owned wind power pumps into the grid. They want their plants up and running all the time, for maximum profit and return on the capital of the plant. So now they'll just fine the green power sources to force them offline when their extra power is not required. I bet nobody figured that into the ROI calculation for the windmills.

[Manedwolf]

Prop driven aircraft have had adjustable props for many many years.   Put adjustabe props on the wind turbines where they can feather the props, or make them where they turn right angle away from the wind. 

Actually they probably have them that way now, the owners just don't want their generation ability to stop.

They are featherable. They have to do that in storms, or they'd go overspeed and come apart.

That Vestas shown exploding in Holland, I think, the braking system failed and it refused to feather in a windstorm. The result was the famous video, with the sudden and explosive materials failure of the blades, followed by the stresses tearing the pylon in half. I think some people were looking sternly at Vestas about some design issues with that one.

[ilbob]

I haven't run the numbers, but I've heard that compressed air is a miserable store of energy.

as i understand it, the process is about on par with energy storage in load acid batteries. most times, the cost to store electricity in lead acid batteries over the life of the batteries on a per kw-hr basis exceeds the value of the electricity.

e.g. - electricity may be going for 5 or 6 cents a kw-hr but it may cost 20 or 30 cents to store it in a battery. there may be some potential for using it as a time shifting means to eliminate expensive peakers.