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Power Electronics Help to Control Electrical Grids
An anonymous reader writes: "IEEE Spectrum magazine has a timely article about how power electronics are proving necessary for the widespread connection of wind turbines to the electric power grid. It explains many issues that currently make it difficult to utilize wind power. Older articles discuss other issues affecting the nation's power grid."
Maybe what we need is more control over the power, we need better systems and routines to warn us before something goes wrong. Not after.
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A little ironic that this article on a world wide power grid was published in the September issue of Wired.
:)
IEEE Spectrum magazine has a timely article
It's kind of funny how articles about the power grid appear in magazines across the world every month of every year, but the ones that just happened to appear this month are "eerily prophetic".
The critical point here is that to have "exotic" devices, you have to be able to manage them to make the power grid meaningful stability. Often, the hip environmental crowd (okay, so I am often one of them), complains that there isn't enough use of alternative energy in the mainstream grid. However, if we dedicated a meaningful amount of the grid to energy extracted from yak dung, what happens if there are problems? The grid elsewhere has to make up the slack (often at a higher price and inefficient) or we have problems like last week. The more technology develops, the more we are likely to be able to use alternative energy...goo goo gah joob.
Lots of stories about home fuel cells powered by natural gas, like this one. No trucks, since most local codes would not allow you to store two months worth of liquified natural gas in your garage or backyard. Heavy dependence on the natural gas delivery pipes. Some potential problems (all amenable to solution, I believe, just be prepared to spend money):
While it's true that most wind turbines use induction generators, they do so for several reasons, including:
All the turbines I have worked with have either had modest capacitor banks to correct for reactive power, or used insanely cool AC/AC back-to-back inverters to produce line quality AC.
I'm also concerned about the article's allegations of power intermittence. Wind turbine rotors have a fair amount of rotational inertia, so they're not capable of passing every flutter of the wind to the generator. It seems that this part of the article is a sales pitch for a new product that the vast majority of installations won't need.
I was also amused at the requirement of wind turbines to "ride through" grid frequency variations. This is basically a nice way of spinning the fact that wind turbine controllers are often far more picky about the frequency they'll accept or put out, than the rather poor regulation that applies to our power grids.
An finally, that picture. Where on earth did they get it? Apart from the fact that it's a contravention of every safety code to climb the tower of a running turbine, the climber must be a human sloth. To get that kind of motion blur on wind turbine blades, you'd have to have several minutes' exposure. Thus our perfectly sharp climber (and their horse) must be moving incredibly slowly ...
We either need more power plants, to curb demand, or a fairly efficient way of storing excess power capacity in the winter to be used in the summer.
All you need is a means of storing off-peak supply for on-peak demand. I hear that in British Columbia, they pump water back up into hydro-electric reservoirs during the night. Maybe regular power plants can have big flywheels.
We can blame the environmental movement for there not being enough power plants.
GE manufactures a turbine rated for 3.6MW output. Ge is currently an industry leader in these types of turbines though, they are desiged primarily for offshore use. Smaller MW ratings between 1.5 and 2.8 are more common. Unfortunately, even with wind turbines producing @ 3MW it would require approximately 1.26 Million of them to meet the U.S.'s current power demands. Currently Coal plants are responsible for the majority of our power capacity in the U.S.
While the *idea* of wind power is certainly a nice one, and the notion of helping the environmement is well intentioned, the reality is that wind is insufficient as a power source and as a result - it's ability to displace the most polluting source, coal, will be ineffective. Other solutions will be required to truly solve the pollution/capacity problem that we face.
A potentially viable start to "solving" some fo these problems would be to distribute residential power generation, especially in dense urban areas. Technologies such as fuel cells, and compact turbines could be used for this. An added benefit of this strategy would be zero emissions and heat reclemation in the case of fuel cells, and better regulatory control over the emissions of compact gas fired turbines.
My two cents.
Bullshit, we can blame ourselves for overconsumption and the NIMBY's (Not In My BackYard) more than the environmentalists.
f er Nuclear in much higher mix than we do today. We also need more cradle to cradle industries that take waste products and turn them into fuel for the next industry - reducing power consumption and limiting the need to dig more out of or cut more off of the earth.
I hate that knee-jerk response to everything - "It's the environmentalists fault".
Even with all the technology that we've created to make lower power devices we just find a way to get more devices. I saw how they were working on LED's as a better, more efficient lightsource that can do task lighting for about 1 watt of power. I mention this at work and some jackass comes up behind me and says how cool it would be to be able to have a wall full of them and be able to change the color of his walls with his mood - POWER SAVINGS - what power savings?
It's a balancing act. First we have a grid that's just too old and extremely expensive to update. There's a mix of powerplants that are aging, there's poor planning, no incentive to change energy usage habbits, poor city design that promotes heat which in turn increases energy consumption due to airconditioners, extra showers, fans, and refridgerators. Then you have people who don't want a soot belching powerplant in their backyard, or off their favorite camping spot, nor do they want to pay extra for a more expensive cleaner burning plant, or pay extra tax dollars to have research into alternative plans like more efficient solar/wind/water/et al. Somewhere in there you have the environmentalists trying to conserve as much of nature as humanly possible before we end up having to chop down all the trees just to put up oxygen factories because we cut down too many of the fucking trees.
Noone wants to compromise their lifestyle to get to plan X, Y or Z.
My feeling is that we need a decentralized system where power is created in much smaller "nodes" and distributed from those points. Nodes could be created in house basements or in larger buildings and be connected to more evenly distribute power over shorter distances reducing the waste that happens when power has to be transmitted over miles and miles of cable to a destination. Additional efficiencies could be found as nodes throttle based on time of day and demand for their area. Grid failures would be reduced because nodes could throttle based on the failure of other nodes. We need more expensive but higher efficiency (and somewhat safer (no oil fires)) superconductor main lines. We need more incentive and more instructions on how we can save power and reduce use and what power saving products are good and can in turn save us money. We need much more diverse power sources Wind/Sun/Hydro/GeoThermal/FuelCell/Gas/Cleaner-Sa
I want giant catapillar like machines like TBM's that crawl through landfills chewing up trash and spitting out useful products. Sorting all the garbage into recycled materials and fermenting the rest as fuel to continue on in it's job or produce energy for nearby cities.
I want to see someone come up with a plan that doesn't attempt to single out ONE group of people as THE PROBLEM.
"Do not be swept up in the momentum of mediocrity." - anon