Windmills Overload East Europe’s Grid, Risking Blackout
businessweek.com
businessweek.com
The actual operation of an electric grid is a delicate balancing act between supply and demand.
-- the grid needs to respond in real-time to changes in supply/demand (weather induced outages, Germany using your grid as an energy sink)
-- the grid needs to respond to daily fluctuations (day/night cycles, cold day, warm day, etc)
-- the grid needs to respond to medium-term fluctions (scheduled maintenance on plants and infrastructure, seasonal variations, price of coal, natural-gas, oil, etc)
-- the grid needs to respond to long-term fluctuations (new infrastructure, recessions, regional economic growth or decline, technological changes, etc.)
On top of all this, governments can change the regulatory environment on a whim thus invalidating many decisions made with previous assumptions.Back to the original article, wind energy is particularlly problematic for the grid because its output is highly variable, not predictable in the short-term, can not be economically stored except in specialized cases, and is rife with government-induced market distortions that are also not all that predictable in the medium and long term.
This hasn't really been a problem before but with real interest and focus on that problem it will surely be solved and will eventually be small footnote as a short term problem we once had on the way to a future in which we will produce energy solely from renewable sources.
The fact that Germany is producing more energy than it knows what to do with is actually good news as it shows that the Energiewende is working.
At the very least it's surprising they aren't pumping water uphill, or just shutting down hydro throughput, in these time periods. Or perhaps Europe's system of hydro electric dams isn't large enough.
Even so such plants are used in the Middle and South of Germany where hills and mountains exists but you have to get the energy there and Poland is closer.
There is probably a middle point here tho: Europe may have proportionally less hydro available. In fact it looks like Germany now has more wind capacity than hydro (something no where near achieved in California) so you're right: they might not be able to make it up that way.
The article seemed to indicate that this is not the case, and that until the south and north parts of the grid are well-connected domestically, excess power from the north gets routed south via Poland and the Czech Republic.
A HVDC network going from north african deserts to norwegian n mountains could solve some problems.
Also, about the German grid: http://lehre.umweltpruefung.tu-berlin.de/mw/index.php?title=.... Germany has less need to distribute power east-west because, if there is wind in the Northwest, there will likely be wind in the northeast, too, but there, statistically, will be less sun in the south. Similarly, having sun in the south correlates with less wind in the north.
Southern Germany gets part of it peak loads from Austrian pumped water reservoirs. But this does not solve the problem, as the energy trade between Austria and Germany is hampered by insufficient transmission capacity between the two countries, causing the neigbouring countries networks to take the load.
In other words, it exacerbates the problem rather than fix it.
(another reply explained why this isn't easily done within Germany: Lack of suitable potential reservoirs)
And in the long term, why is Europe not building more Pumped-storage hydroelectric power plants, which would solve the issue? (https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...)
Northern Germany probably doesn't have a single such plant but Northern Germany also doesn't have a single mountain, hill or anything higher than a tree as far as the eye can see.
You will find those plants in Southern Germany and Austria but then again they do actually have places to put them.
Besides stopping the windmills or installing plants is not the problem. The problem is that the German grid can't deal with the energy produced in Germany and uses neighboring grids that are not designed to handle that much load.
Most of them will come with bs excuses for why only oil is the solution and everything else doesn't work.
There is no such thing as "too much energy produced" for a start. As you said, they can brake the blades, or just disconnect the generators, easy.
Storage and variation of power are real problems, but they can be dealt with.
I'm not exactly sure about the electrical machinery, but if that is sophisticated enough, it can be used in high accuracy fashion to control the generation so that the electeicity is produced in high quality.
You can think of the wind plant working as a giant flywheel. If there is a sudden gust, the spin speed increases and the extra speed is gradually harvested as energy. No sudden spikes. In theory the plants could be used to improve the frequency quality even more by also acting as motors.
If there is a real wind powef power electrical engineer around, feel free to chime in.
>Wind farms in West Texas earlier this year were paying utilities to use their electricity on particularly gusty days because they can still earn $22 a megawatt-hour in federal tax credits
As long as their neighbours let them, it's vastly cheaper for Germany to keep this going than to speed up the upgrades of their own transmission capacity.
Also, the power network is still very "former East - former West" built, which is not helping. We had 3 years ago a blackout of the West while the East (which includes the part with most of the windmills) was still up.
At the end, the problem is mainly because of the delayed investment from the network operators and they are now affected by their own unwillingness to build the network. From a financial point of view, it is easy to understand because they are mainly coal/gas/nuclear producers and they would have had to build a network which would then be used by their competitors...
You're right that the former east has its "own" grid operator [1], but there is much more installed wind power in the north west[2].
[1] http://de.wikipedia.org/wiki/Stromnetzbetreiber#Netzbetreibe... [2] http://de.wikipedia.org/wiki/Windenergie#Deutschland
Makes for some very interesting arbitrage opportunities, even if it is residential only (I assume).
I expect the same solution. More transmission capability or charging more and fixing the market issue. This really is a market issue in that the east europeans don't charge enough for transmission costs to stop the Germans from doing.
Production variation is a problem but not such a big one as price volatility and consumer (demand) volatility. i.e. power demands at peak times. i.e. when everyone wakes up and turns on their coffee machine etc...
Large (esp. direct drive) windfarms are actually good at dealing with the demand volatility as they can spin up and down in minutes. While weather volatility is in the hours. Same day weather forecast is very good. So inside a grid windfarms are nice. Its when transmitting outside the grid like nuclear they can be mean to other producers.
However, is there a more simple solution to this problem, like approaching an industry that already uses masses of energy and seeing if they can encourage them to use the energy when there is overloading? I'm unsure what that industry would be.
Surely using an overabundance of energy is a solvable problem? It seems bizarre to me that it wouldnt be.
I spring is a material (usually a metal, but could be a plastic as well) that is under stress, typically tension, torsion or compression (depending on type of spring). The limit is basically the yield strength of the material, which is the point where the stress vs strain curve goes nonlinear and the material begins to plastically deform. Obviously the fracture limit represents catastrophic failure of the material, but that is higher than the yield limit.
Basically, it's a material strength and elasticity problem.
Cold storage is apparently a pretty big industry there, and all those buildings are designed to be highly thermally-efficient anyways. There's also a huge segment of the cold storage market where the exact temperature of the storage doesn't matter, it just needs to stay within a specific band.
So what happened? The experiment (which was successful) effectively turned the freezers into batteries. The control systems were set to lower the temperature to two or three degrees lower than usual during the night (which made the cooling plants run longer then), and the plants were scaled back to maintenance power-levels during the day, when demand was higher. The grid was happy, since it moved the load to a low-usage time. The storage owners were happy, since they got a deal on the evening electricity. And the things being stored didn't care, since they were all so far frozen anyways. I wonder if you could do a similar program to get them to cool down further when there's excess power on the grid?
Or to solve this at an earlier point, why not just turn off the windmills when the power's not needed. All the windmills in my community have setting that when the wind is too high, the blades on the windmills pivot to the zero lift axis, and they don't spin.
Because the subsidies in Germany are tied to the amount of electricity sold. That's why they're selling even at negative market price -- to collect the feed-in tariff.
Yes, the problem is solvable - improve the grid so that too much energy in one place can be distributed around to where it is needed.
The simplest way to achieve that is probably reasonably sized energy trading areas - that will make the cost for transporting the energy baked into the price in a much better way that how it works in big unified trading area.
http://lightsailenergy.com/tech.html
Another Bay Area energy startup to watch!
http://seekingalpha.com/symbol/amsc/description
From a description I once read (but can't seem to locate right now) these devices store excess power for short periods in superconducting coils to release the power again when the consumption side needs it. That way both the grid and the windfarms are matched better to each others needs and capabilities.
The whole thing is housed in a 40' container.
By the way, all the wind turbines I've seen can rotate their blades 90deg, so they come to an almost full stop if/when necessary.
It's easily fixable in any number of ways. It's a matter of political will (and cost - both investments and potentially in buying their way out of short term obligations to prevent problems this winter), mostly.
http://www.ted.com/talks/donald_sadoway_the_missing_link_to_...
Its not impossible. It just wasn't a requirement before so there hasn't been a lot of focus. There are technologies out there right now that would probably work ok. If not, energy storage just needs more focus.
This one looks very promising (http://lightsailenergy.com/tech.html) and I'm sure there are a lot of other viable approaches.
The fact that they have excess power that needs to be stored and then redistributed is GREAT news.
One person mentioned something about needing to store power for months. Obviously, that long time frame is not the requirement.
(Edited, realised it sounded confrontational to begin with.)
Why don't Denmark and Spain experience such "blackouts" when these two countries have a higher wind energy capacity/production compared to CZ/PL?