Tech Allows Stable Integration of Wind In the Power Grid 235
diegocgteleline.es writes "One of the most frequently raised arguments against renewable power sources is that they can only supply a low percentage of the total power because their unpredictability can destabilize the grid. Spain seems to have disproved this assertion. In the last three days, the wind power generation records with respect to the total demand were beaten twice (in special conditions: a very windy weekend, at night): 45% on November 5 and almost 54% last night (Google translation; Spanish original). There was no instability. These milestones were accomplished with the help of a control center that processes meteorologic data from the whole country and predicts, with high certainty, the wind and solar power that will be generated, allowing a stable integration of all the renewable power. You can see a graphic of the record here."
Good, but by no means a complete solution (Score:5, Informative)
Wind generally changes slowly enough that it doesn't cause massive instability providing you have sufficient backup. However, there are other problems.
Getting the percentage that high occasionally isn't amazing, especially during a time of low demand such as night. The hard part is generating an average of 50% wind overall (e.g. over a year).
Say the baseload demand is 20 GW, then you can have 20 GW of wind power installed without worrying about what to do if too much is produced. So you could even get nearly 100% wind power occasionally. The problem is for the rest of the time when demand is higher or it isn't windy. The capacity factor of wind is about 30%, and baseload is typically about 50% of average load, so that means on average you're only generating 15% of your total electricity by wind power.
Re:Does not change the basics. (Score:5, Informative)
Sometimes the wind does not blow at al
RTFA. and read up some more on how wind works. No wind in place A = center of cyclone or center of anticyclone, meaning that a few hundred clicks in any direction there IS wind 100% garanteed. (unless the moon would magically disappear, the sun would magically disappear AND the earth would magically stop turning)
There are two sides in that coin... (Score:5, Informative)
First of all, I want to remark the great work of the REE company ("Red Eléctrica Española" stands for "Spanish Electric Power Network", the monopoly for electric power distribution), they not only do a great work routing and adapting the production to the user energy demand, but also provide a lot of useful information about power consumption, production/consumption balance, etc.
The dark side of the problem is that although there is a huge amount of "green energy" being generated in Spain (wind and solar), that is, paradoxically, a problem. The problem is because current "green electricity production" is above 20% of total energy production, which sounds great, yes, the problem comes from nuclear power being dismantled from past 20 years, so the electric bill goes up because of the more expensive production (the solar energy production is specially expensive, which has been subsidized ad nauseam). Now the country faces near 19% unemployment rates (almost twice the U.S. figures), paying a huge price for energy, with the country in the middle of its worse recession since the post-war era (40's).
Re:Stupid technology (Score:5, Informative)
Coal and oil are plentiful, cheap, and easy to use.
Coal and oil are plentiful, but you know whats more plentiful? The solar radiation and wind, both are unlimited.
Coal and oil are cheap and easy to use because we have spent massive amount of money improving them over the last 100 years. Given enough research it is entirely possible that solar and wind will be as cheap as oil (coal would be tough to beat though). Solar power however will likely end up being easier to use, no fuel, no exhaust, and no moving parts.
... and hurt the eyeline of the cities they are installed in.
Ever heard of smog? I would much rather see a bunch of solar panels and windmills, than a giant brown haze of asthma attack and carcinogens.
And people wonder why environmentalists are considered stupid.
They are called stupid because what they are promoting is bad for business. Switching to these technologies is not efficient yet, but as this article proves they are getting closer. Big businesses and their propaganda machines (eg. Fox News) want to cast these technologies in negative light to avoid having to switch to them, which would cut into profit margins.
Oh and did I mention that these technologies could one day remove the USA's dependence on foreign oil, reduce medical problems, protect the environment, decentralize the electrical system, reduce power lost during transmission (local power generation), and be better suited to installation in 3rd world countries?
Or of course, we could just keep using the current system until our resources run out and then start looking for the solution.
Sorry, Nothing proved with one 3-day weekend (Score:5, Informative)
Just think of this. You've now made something like 80% of your grid powered by wind. (They all have problems, but let's just look at wind.) You have a doldrum for a day or two, now you've gone for that time period with only 20% of your normal power, that's destabilizing.
What if your windfarms are spead out over vast distances so they tend to have different local conditions. (Something like if you have them all over the USA.) In some ways that will help since no location is expected to be the same as the other, so there is an averaging effect going on. However, that averaging effect is limited by long distance power transmission issues. The grid isn't just a pull & dump system. It uses power to send power, and it needs to maintain what you could think of as electrical pressure, (V.W.A. formulas.) which is why you have all those transformers and sub-stations all over the place, they are one part of that system. So even in the distributed scenario, what if you get a situation like high-wind on the east coast, and calm conditions mid-continent, and dead west coast. Funny thing, the need for power didn't decrease anywhere, but only the east coast is generating enough for their area, some of the mid will be ok, others in brown-outs or black-outs, and the west coast would be mostly black-out conditions, except near the few remaining alternate power sources, assuming the grid demand didn't leach it out completely and blow the circuits. (The entire east coast USA was blacked out by a cascade grid failure, and it might happen again.)
Of course having multiple sources of power helps offset this kind of issue. For instance, solar. But that would only help during the hours of light, and again, it needs to be within a reasonable distance of it's market/users.
All this stuff is why intelligent power managers advocate a number of different generation schemes distributed over the area with clustering (when possible) near high draw locations (like big cities). And no power manager can rationally turn a blind eye to those methods that run 24 hours on demand.
I agree that we need to expand our renewable resources type power generation, as well as move away from fossil fuels, but it's a tricky balancing act with huge penalties for dropping the ball, so don't trivialize it.
Re:In before the whiners (Score:1, Informative)
Dude,
You over constrained the problem with "no possible variation"! Heck there's variability with peaker gas turbines (that's their purpose), should we not use them?
Ever consider using batteries to store excess power from solar cells to get you through the night?
Get out from the basement and go take a tour of some homes that live entirely off the grid. They use storage to get through the lean times...
Re:Solar Wind (Score:3, Informative)
idiot. If no energy is taken out of the wind: It would start to blow faster and faster. Furthermore, if it is not taken out by windmills, it will certainly be taken out by houses, trees, mountains.
Re:Manzanas and Oranges (Score:3, Informative)
With HVDC you can say "transport 500MW" and it will transport that amount, and if the consumer end tries to sink 1GW, the line will just keep providing 500MW.
That is wrong. If you attach more consumers to the line the line will break down (voltage and with voltage current will break down).
To make an AC grid work you need a strong central authority who can tell everyone how much to produce and when, and this is incompatible with both a free market for electricity and a large amount of power producers.
As soon as you have more than 1 powerplant and and more than one consumer you need that anyway. Probably you should read up how grid management works.
It is absolutely not against a free market. In short: energy distribution/market is divided into a) energy producers, b) network operation, c) power traders. Power traders buy energy from (a) energy producers and deliver the energy to the customer by renting (b) network capacity. Power Traders have to announce their daily demand (precalculate) to the network and the power producers. The gap between announcement and consumption (either positive or negative) is covered by the network (with reserve power plants, there are several levels of reserves categorized depending in their response time (1minute, 30minutes, 60minutes, 120minutes). Long response times are covered by the network but again rented from the energy producers.
The energy market is moving more and more into a situation where the consumer is buying his energy at a stock market and the energy traders as well as the energy producers and also the network providers offer their services at that stock market.
Without a detailed accurate schedule of demand and production (one day ahead, minimum) no modern power grid would work at all.
angel'o'sphere
P.S. wikipedia provides a nice overview how energy networks and reserve energy and the trade works
P.P.S. sorry for the simplifications, how ever I worked the last 10 years as software consultant mainly in the energy industry, so I have a good idea how it works.
Re:Good, but by no means a complete solution (Score:2, Informative)
Re:Manzanas and Oranges (Score:2, Informative)
can you expand on this? Is it a synchronous machine inside a wind turbine? They can be used as a synchronous condenser to supply reactive power when the turbine is stopped?
What electronics can do this?
It's typically induction or permanent magnet generator inside the wind power plant. As far as I know synchronous machines are not used because wind cannot rotate the blades at a constant speed. The power is supplied to grid with frequency is converter. Frequency converter can supply the grid with reactive power during the disturbances.
see:
http://en.wikipedia.org/wiki/Low_voltage_ride_through
Re:Stupid technology (Score:4, Informative)
The wind occurs in the bottom ~5km of the atmosphere. The largest windmill is ~100 meters tall, covering the entire planets surface with windmills would have about the same effect on wind as covering it with large trees, ie: virtually nil.
People rarely appreciate just how much power the wind has, on the day of the Aussie bushfire disaster last Febuary, I was sitting at home sweltering in 47degC heat fed by a 100km hour wind coming off the desert, native bats and birds were literally falling out of trees dead from dehydration, my punny fan on a stand did nothing to aleviate the discomfort unless I got out of a cold shower and stood in front of it still dripping. Ironically these winds and the blast furnace conditions they bring are created by cold fronts moving in from the Antartic, when the front passed over Melbourne that day, the temprature dropped by 15deg in 15 minutes.
Now to put windmills cumulative effects on the wind into perspective think about running them in reverse and how many you would need to to drag that amount of cold air from Antartica to Australia.
Re:Does not change the basics. (Score:1, Informative)
"Solar isn't going to help much, even if we paved all of Arizona, Nevada and Southeast California with silicon."
Not true.
Fact check: A 100x100 mile area in the southwest could supply all current electricity needs in the USA. Actually, a plot of that total size in arizona with mainstream 12% efficiency panels, would supply twice the kilowatt-hours per day than the current daily demand.
But of course, most large-scale solar will probably be solar thermal, not photovoltaic, because for that some very efficient storage techniques are being developed to match plant output with demand fluctuations (and to fill the 'night gap')...
References:
http://www.environmentflorida.org/newsroom/energy/energy-program-news/large-scale-solar-power-plants-could-power-nation-combat-global-warming-and-create-thousands-of-jobs [environmentflorida.org]
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x203056 [democratic...ground.com]
http://www.physorg.com/news176632405.html [physorg.com]