Growth in wind power makes life difficult for grid managers
oregonlive.com
oregonlive.com
See: http://www.treehugger.com/files/2010/06/smart-grid-demand-re...
Storage means you can get energy out of it, not simply make it use less. But yeah, a smart grid is effectively necessary for any possibility of improvement.
Still, though, it's all about reducing demand, not modifying supply. Flywheel storage can literally pump juice into the grid, temporarily raising the net energy level (yes, by reducing it earlier, similar to the freezer). And because of that quality there's a huge potential market, because those high-stress times are when electricity costs the most.
I guess my point is that, with flywheels, you can make money through nothing but the power grid. With a freezer, you can only reduce how much you lose.
Make your water hotter when there's a surplus of electricity, that way you'll need less later when that surplus might be gone. If you have control of millions of water heaters, that's a lot of buffer.
No wonder they like nuclear so much; not that I am against it, but we can generate as much or as little as needed on demand. Seems to me this is an issue of an antiquated grid system that needs an overhaul. We are still running a 10Mb/s network and needs to update to Fiber as an analogy.
I would think hat if there is excess, it would be stored to use when there is a demand for which we can't supply. Apparently that is not the case?
Ok, 6 gigawatts of capacity. Let's say you want to store 12 hours worth of wind capacity. 6GW * 12 hours is 260 terajoules, the equivalent of 61,000 tons of TNT. Not only do you have to build a system that can safely store and dischange that much energy, but it has to be cheaper than current power generation methods.
For most intents and purposes, interim storage of electricity is science fiction. Batteries are woefully inadequate, and the solutions that we do have, like pumped storage, have so long turn-on times that they might as well not exist for spikes that fast.
This is the biggest narrative about energy production that is left unsaid in the general discourse. There are two distinct markets for energy -- the baseline production, and peaker production. They are different enough to be thought of as entirely different industries. Wind has the misfortune of not belonging in either.
(http://upload.wikimedia.org/wikipedia/commons/3/33/Dlouhe_st..., 2 × 325 MW for 6 hours when full, ~250 millions EUR to build)
656MW of power generation/storage, built for $103 million in the early 1960s.
http://en.wikipedia.org/wiki/Smith_Mountain_Dam
More here: http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
http://www.treehugger.com/files/2010/06/smart-grid-demand-re...
Basically, if you can control lots of water heaters, fridges, refrigerated wharehouses, A/Cs, etc.. You have a way to store power (f.ex. you make the water a couple degrees hotter, or the wharehouses a couple degrees lower). Not enough to affect what's in it, but enough to use that extra power and "store" it (which buys you time, and means that you can use less power later, ie. shut down a gas plant or whatever while all those things revert to normal temp).
Maybe the wind farms should install their own buffering systems. If they built reservoirs on hilltops then dumped their excess electricity into their own pumps they could avert this "all or nothing" issue by delivering power to the grid on a more consistent basis with fewer spikes.
The absolute worst thing that can happen is that wind farm owners will have to scale production down because they can't sell it. Sure, we'll be wasting some energy but without storage, what can we do?
If this problem is so frequent, get more export lines and sell the excess elsewhere (and, conversely, import when you're running low). Why is this portrayed as a problem at all?
Many wind farms have serious problems being economically viable because their production is too unpredictable. Those export lines might never make back their initial investment, because the price you get for suddenly selling electricity to be provided tomorrow on the open market will be at least an order of magnitude less than what you get for stable contracts, and conversely, if you need some to be provided tomorrow, you might end up paying a lot more than you expected to.
The only solution that I have seen to work is to find some industry that can afford to let their equipment sit idle while they wait for cheaper electricity and make a contract with them.
http://www.nytimes.com/2010/07/28/business/energy-environmen...
Could wind farms have local pumped water storage work available (eg for water towers) or dedicated lines to pumped hydroelectric stations so that the power output could be chosen and excess power diverted to pumping water for later use (use for power gen' or water transport).
Or would fly-wheels or heating be more efficient.
If the wind farms aren't listening or the order doesn't go out or there is any sort of communication problem, the excess power could overload the grid. This is a fail-deadly situation.
If this problem is so frequent, get more export lines and sell the excess elsewhere (and, conversely, import when you're running low). Why is this portrayed as a problem at all?
From the article:
Building new transmission, though, is an uphill battle. New lines often require new rights of way through sensitive habitat and private property. And they are phenomenally expensive, raising the show-stopping question of who pays.
Everyone's overlooking the other thing mentioned in the article: The new wind farms aren't cutting down on non-renewable usage. If too much wind power is generated, the BPA reduces hydroelectric generation.
In that context Wind + Hydro = base load power and together they can replace Coal power plants. The worst case situation where recent rains mean the hydro power plants need to produce energy or waste it, at the same time a wind farm can produce extra energy is really an edge case that has little real impact. The issue is at the other end, when there is little rain or wind for a long time.
I can also see GP's caution as a way for power companies that rely on non-renewable resources to curtail this type of renewable energy production.
"It will destroy the grid!"
If I had considerable investments in coal, I would make certain that wind would destabilize the grid for a bit, and point my finger and say, "You can't use wind. It will destroy the grid!"
Now traditional hydroelectric http://en.wikipedia.org/wiki/Hydroelectric get's "free" energy with short bursts (floods) that's gets released over several months, but other than that it's almost identical to pumped storage in that you can release more or less energy within minutes of changes in demand. In the past they tended to be used for base load power, but they all have a capacity factor which is average output / max output and in the USA it averages out to 42%.
As to the mechanics: Worldwide, an installed capacity of 777 GWe supplied 2998 TWh of hydroelectricity in 2006.[1] This was approximately 20% of the world's electricity In theory if you add 2998 TWh of wind power on average, and can release 2x base load hydroelectric on demand then you can replace 20% of the world electricity generation with wind power and have little impact on the grid. Realistically, wind power over large areas is not going to drop to zero, also hydroelectric power is not setup to produce zero energy one minute and 2x that energy the next and not all hydro has the ability to store energy http://en.wikipedia.org/wiki/Run-of-the-river_hydroelectrici.... Plus you have transmission losses ect but hydro + wind can become very close to base load power especially if you slightly overbuild and accept the loss of some of your peak power aka 10% extra generation 3% of the time = 0.3% wasted capacity. For comparison Transmission and distribution losses in the USA were estimated at 7.2% in 1995 http://en.wikipedia.org/wiki/Electric_power_transmission
PS: Also the transistion is a fairly slow process, so we have several years to get things working.
No. The absolute worst thing that could happen is BPA failing to curtail power production spikes that end up disabling the entire network. If the spike of power is big and sustained enough, and if the supply isn't cut back quickly enough, you could blow out the whole grid. Want a couple of weeks of a state-wide power outage?
The grid is just a large web of wires. Unlike packets in a tcp/ip network, you cannot control which wire an electron will travel upon (except that you can deny a wire any electrons by severing it from the grid)
Each wire can handle a maximum amount of load, before it starts to heat up. Heat it up enough, the line will short out.
The BPA balances the amount of electricity entering the grid against the amount of demand. They need to worry about the overall grid, and also each local area.
If a local area starts getting a lot more power, they have to make someone in that area cut back production before the infrastructure gets damaged.
Power units generally don't just cycle on or off. There's a lot of work involved in shutting down individual power units and some of them need a lot of lead time to cycle back up to their normal output.
get more export lines and sell the excess elsewhere
[edit: spelling]
I have no idea how plausible something like that might be.
That's not quite true, true at an electron scale, but you can alter the resistance of a particular line to alter the current (the gross electron flow) that passes on it. Severing is just the extreme (operationally equivalent to infinite resistance added).
[Electronics was always a weak point for me.]
Why can't someone just build a wind turbine that has the similar function of switching gears like the mountain bikes do?
If the blade moves too fast it can switch gears and makes it harder to spin the blade - wouldn't that produce less energy and fix their problem?
Wind power is good, it's just extremely unreliable and storing it is a harder problem than you'd think. One of the regular users here, DaniFong, posted some good comments and articles on how difficult it is to store power. If you started at her profile and clicked around, she's made some quite insightful points on the topic:
Adjustable gearing would add a lot of complexity, weight, and reduce reliability. Reducing efficiency by (partially) feathering the blades is a much better method, especially since it is already a necessary capability of the windmill.
On the afternoon of May 19, in a single chaotic hour, more than a thousand wind turbines in the Columbia River Gorge went from spinning lazily in the breeze to full throttle as a storm rolled east out of Hood River.
Suddenly, almost two nuclear plants worth of extra power was sizzling down the lines -- the largest hourly spike in wind power the Northwest has ever experienced.
And some potential partial solutions, if they can get them implemented:
Part of the problem is that utilities buy more capacity than they need, and hoard it for emergencies. If that capacity can be freed up, BPA estimates the lines could transfer 10 to 15 percent more power.
Another issue is that utilities are required to reserve line capacity an hour ahead of time. By allowing them to adjust their orders more frequently, utilities could accommodate unanticipated ebbs and flows in wind generation and maybe free up another 25 to 30 percent of capacity on the power lines.