True enough. With Cassini, its design is "of its time" - newer versions of the same instruments would weigh less, and huge weaight/fuel saving could be made by using ion drives (SEP/RTG powered) at least in part.
The point is that smaller more frequent missions mean newer tech being delivered to target at any given time.
For example, is it right that there is a huge gap between Galileo & JIMO missions? Would smaller/cheaper mean continous orbiters returning science?
Limited bandwidth is a problem, but an orbiter such as Cassini has long gaps between major orbital encounters to pump data back. Of course if the problem is limited storage/processor, then we are back to my points.. But look how well Galileo did even with no hi-gain antennea!
The MER rovers are also interesting - part of the problem is lack of computing power. The 1985 style/speed processors do not help - think of the benefits of having decent processor power for compressing image/other data before it is sent..
Thanks, interesting post, although I think now they are replanning to send a big mission to Jupiter (JIMO) instead of a smaller option.
My own belief is that, despite your valid points, you get more data overall with more diverse & less expensive missions, and economies of scale by making many copies of one design. That way for example, two+ orbiters could have been sent (and updated for continous presence) to both Jupiter and Saturn. As things are we tend to have rather too few missions, with very big price tags.
When you look at the disaster that so nearly crippled Galileo (hi gain antenea failure), redundancy matters..
Re:I dont want to steal their thunder..
on
Titan's Alien Thunder
·
· Score: 2, Insightful
Optics do matter, but it is wrong to say that the sort of quality of optics on this craft would not benefit from a higher resolution CCD.
Make the missions faster & smaller in scale, you turn it around quicker (and more often) & hence deliever more up to date tech for any given timescale..
Cassini missed a launch window due to delays - so it had to take much longer to get to Saturn. If it had gone to plan, it would already be orbiting & taking 1mp photos for a time, and if the budget would have been less we could a launched another follow up with higher resolution cameras.
I thought one of the things that did come out of "Faster, Better, Cheaper" in the end was New Horizons to Pluto.. The examples I gave illustrated that some teams can do missions at a much lower cost..
I dont want to steal their thunder..
on
Titan's Alien Thunder
·
· Score: 4, Interesting
This is going to be a fascinating event - however I do have some questions.. The total mission cost is around $4 billion - is this good value for money? For example look at New Horizons, a Jupier/Pluto/KBO mission with a total projected cost of $600 million. I also wonder, given the scale of the mission, if a RTG should have been put on board Huygens so that it could stay longer and observe the Titan environment over a longer time? (Yes I know it could only relay data when Cassini passes by, but that could still be useful..) Listening to thunderstorms is all well and good, and adding a mic is worth doing because its a cheap thing to do in such a system, but what about a lander that spends more time there looking at the chemistry of Titan?
I think that the smaller, cheaper missions return much better scientific return for the money. For instance, most of the function of the proposed $10 billion JIMO mission could be done by a cheaper Europa-only orbiter that would cost less than $1 billion. (See: http://www.spacedaily.com/news/hubble-04p.html ) Also take a look at the SMART-1 ESA mission - less than $100 million for a complete mission featuring many new technologies.
For example the camera on the $4 billion Cassini mission is only 1 megapixel - if we had a larger number of smaller, cheaper missions, would we be there now with a much better imaging system. Cassini had a much delayed launch, so the design was outdated by the time of its launch in 1997. The same mission launched on a later window could have used ion propulsion (SEP/RTG combo) saving weight (1/2 the 4 tons Cassini weight is fuel)
The same thing could happen with JIMO - if NASA spend $10 billion on that, they could forego many other missions, such as a New Horizons II mission, which would give us a chance to look at Uranus (not always a good word to say on Slashdot) with modern instruments, as well as Jupiter & some more KBO's..
Also think about Hubble - is it worth spending $2 billion on a robot to repair the aging telescope, when the same money could buy better new space telescopes.. (see link above)
I dont want to belittle the work of the scientist working on Cassini - it will be a fascinating mission, I just wonder if we could get more return by rejigging the beurocracy.. The X-Prize, New Horizons and SMART-1 prove that more smaller & competitive missions return much more bang-per-buck..
Seems to me you are the one doing the jumping..:-)
(Wouldnt we get better performance long-term from a larger number of smaller probes?)
Most of the cost goes into getting to these very far away places and holding enough propellent that you can slow down enough to be captured into orbit after you've been going very fast for a few years. It's not feasible to launch probes to outer planets all the time because you lose the ability to "sling shot" past other planets as a cheap way to pick up a lot of speed. These gravity assist (or more accuratley, angular momentum assist) moves make a little ship go whole heck of a lot faster which means you don't need as much propellent to get you somewhere. You have to go really fast to someplace that several billion miles away in a few years.
Yes, I understand that. In fact its not all that bad - an opportunity to use Jupiter to sling-shot comes round every 13 months. For example, New Horizons will launch Jan 2006 for Pluto, mission cost $600 million. If a second identical probe is built for a follow up around 2008, we can get a fly-by of Uranus and then some more KBO's, for an even smaller cost. Probes like SMART-1 also conserve power by making careful use of other celestial mechanics & tricks - "lunar resonances", check the ESA site. There are "interplanetary highways" that could even provide "free" trips between planets, all be it slowly..
(and hence would have more up-to-date sensors. For example, the CCD on the Cassini camera is only 1 megapixel!)
The way to get better quality pics is NOT to have more pixels but to have better optics. The cameras in the "eyes" of the Mars Exploration Rovers (the pancam) are only about 1 megapixel and they have returned VERY high resolution pics that look great if you have to blow them up 10 times their size. That's because NASA spends a lot of money to use phenomonally good optics. In addition, more megapixels means larger files which requires higher data transfer rates which requires more power to your antenna which means less electricity to do other stuff. (whew)
Even within limited Bandwidth, higher resolution can prove useful - remember Galileo which busted its high gain antenna, and could only send data to earth at a low data rate? It still did 90% of the science it was supposed to do anyway, by careful use of resources.. I am not saying Cassini is not worthwhile - the results are/will be fascinating. I just believe that smaller/cheaper missions turn around faster and actually put up more modern devices within a given timescale..
(I have heard it suggested that most of the useful function of the JIMO $10 billion orbiter could be done with a simpler $1 billion direct-to-europa mission.. And look at New Horizons, with a mission cost less $1 billion, or SMART-1 less than $100 million..)
Dude, compare apples to apples here. SMART-1 is a test of new technology (ion drive) that is meant to see how well it works and if it useable in other missions. It was meant to be a cheap way to get to the moon. You don't need a whole lot of force to get the moon and orbit it if you're willing to wait a few years...like SMART is. To get to Jupiter and then ORBIT it, you have to go very fast to get there, then be strong enough to slow down to be captured into orbit. Then maybe you'd want a few kilos of propellent left to actually move around near Jupiter for a few year. That is a completely different scope than crusing along to the moon for several years or flying by Pluto-Charon before the atmosphere freezes out.
This is not something I am just pulling out of the air here - for example check this article from SpaceDaily. http://www.spacedaily.com/news/hubble-04p.html We could get to orbit Europa (the main satellite of interest) with a much cheaper mission than JIMO - about 1 billion should do it. In fact, and this is my origin
Good question - in fact there are only 6 replys so far, so I guess people here arent that excited. Also I do sometimes wonder about these big projects - wouldnt we get better performance long-term from a larger number of smaller probes? these can be turned around in a shorter space of time, and hence would have more up-to-date sensors. For example, the CCD on the Cassini camera is only 1 megapixel! (See below)
I have heard it suggested that most of the useful function of the JIMO $10 billion orbiter could be done with a simpler $1 billion direct-to-europa mission.. And look at New Horizons, with a mission cost less $1 billion, or SMART-1 less than $100 million..
From http://saturn.jpl.nasa.gov/spacecraft/instruments- cassini-iss.cfm ISS includes two cameras; a Wide Angle Camera (WAC) and a Narrow Angle Camera (NAC). Each uses a sensitive charge-coupled device (CCD) as its detector. Each CCD consists of a 1,024 square array of pixels, 12 microns on a side. The camera's system allows for many data collection modes, including on-chip data compression. Both cameras are fitted with spectral filters that rotate on a wheel -- to view different bands within the electromagnetic spectrum ranging from 0.2 microns to 1.1 microns.
1) Release an O/S ripped off from a competitor, with no copy protection at a low price. 2) Everyone adopts your O/S because it is cheap to buy, or can be copied for free easily. 3) See off all competition, make the API so huge & unweildly that no one can clone it. Patent bits of it to make sure. 4) Stamp down on copying, introduce draconian licensing scheme that ties every copy you sell to one PC, undermining normal rights of purchasers to resell or move O/S to other PCs. 5) Jack up prices. 6)... 7) PROFIT!
..and it was the first probe to successfully test the Interplanetary Superhighway.
I thought Al Gore invented that..
Seriously could a craft with approx the propellant/mass of SMART-1 use this to get to Mars or beyond? I have often though that large groups of cheap identical probes $100 mil like SMART-1 sent by ion propulsion is a much more effective/interesting model for space exploration..
"You and people around you have scared our children," Smalley fairly shouted in print. "I don't expect you to stop, but I hope others in the chemical community will join with me in turning on the light and showing our children that, while our future in the real world will be challenging and there are real risks, there will be no such monster as the self-replicating mechanical nanobot of your dreams."
Sure its a question of whatever is the most effective. The claim is that direct Hydrogen production/storage is more efficient, but if you have a good battery, do it that way. The current best selling Electric car (UK) does 1.3p/mile compared to 20p/mile for a normal car - but only with 30 mile range on a charge.
My guess is the best solution is hybrid - similar to petro-electric hybrids. Add a small hydrogen engine, so you can run around town off batteries on a cheap overnight charge, but if you need a longer run, tank up on Hydrogen..
It would be much better to just electrolyse off the grid overnight, and use spare off peak power. Then use wind/solar/tide/wave to run the grid - off-peak hydrogen generation helps mke use of unwanted power.. By all means have solar on the car too, it will give you a few free miles every day..
What happens when the wind stops blowing?
on
Can Coal Be Green?
·
· Score: 1
What happens when the wind stops blowing? Much of the following information is taken from an article by DJ Milborrow in WindDirections Volume XIV, No.3 April 1995.
Wind turbines generate electricity from a fuel that is free and will never run out, but which isn't available all the time. This factor of 'non-firm' or intermittent' generation is often cited as a detriment of wind energy, with a popular question being 'what happens when the wind stops blowing'. Not a lot really, as electricity continues to be provided by other forms of generation, such as gas or nuclear. Our electricity system is mostly made up of large power stations, and the system has to be able to cope if one of these large plants goes out of action. Equally, the system is well used to dealing with fluctuations in demand, such as millions of people putting the kettle on during commercial breaks of a popular soap on TV!
The fluctuations caused by non-firm generation of electricity from wind turbines are not noticeable above the normal rises and falls in demand on the system. In fact, it is possible to have up to 10% of the country's needs met by intermittent energy sources such as wind energy without having to make any significant changes to the way the system operates.
For more detailed information on how the system operates and what happens when the wind stops blowing, read on.
Is it a problem? The UK's power system relies on a diverse collection of different types of generation. No individual power plant is 100% reliable, but the system as a whole is very reliable.
There are numerous power stations in the UK. There are around 23 large coal fired plant (some of which also burn some gas or oil), 17 nuclear plants, 8 large oil plants and 11 new combined cycle gas turbines (CCGTs) and several others. Large in this context means over 100MW. (The percentage of generation by fuel type in 1995 was 48% coal, 23% nuclear, 17% CCGT and open cycle gas turbines, 9% interconnectors and 1% oil and the remainder hydro and the new renewables).
Whilst wind still makes up a very small proportion of our total electricity generating capacity coping with the intermittent nature of the wind poses no problem in relation to the other fluctuations in supply and demand which the system copes with. It is very small in comparison with the problems of meeting demand if one large power station is suddenly put out of action.
Even if wind energy capacity rises to 15,000 MW, i.e. enough to meet 13% of the UK's electricity demand during 1994, it would still be a smaller threat than one conventional power station being unexpectedly unavailable.
Putting it into perspective The other threats to the system, which far outweigh the variability of wind are
* Failure of the cross channel link. The UK is connected to France by two 1000MW circuits which periodically fail. Loss of one circuit occurs more frequently than the loss of both, but neither occurrence causes any significant upset to system operations.
* Steam turbine trips - these occur for many reasons, including false alarms. The largest stets have a rating of 660 MW and, again, the system is managed so that these cause no problems.
* Transformer failures - when these occur on the national grid, significant imbalances can occur and load sometimes needs to be shed as a result.
* Thunderstorms - National Grid network circuits can trip out if struck by lightning.
* Unexpected increases in demand - e.g. dark storm clouds can cause a sudden increase in lighting demand. Most increases in demand are predictable and so pose less of a problem.
The imagined threat due to wind generation is simply not in the same league as any of these occurrences.
The output from a wind farm is smoother than the output from a single machine, and the output from a dispersed win
Slashdot Mirror
Everything is a trade-off.
True enough. With Cassini, its design is "of its time" - newer versions of the same instruments would weigh less, and huge weaight/fuel saving could be made by using ion drives (SEP/RTG powered) at least in part.
The point is that smaller more frequent missions mean newer tech being delivered to target at any given time.
For example, is it right that there is a huge gap between Galileo & JIMO missions? Would smaller/cheaper mean continous orbiters returning science?
Limited bandwidth is a problem, but an orbiter such as Cassini has long gaps between major orbital encounters to pump data back. Of course if the problem is limited storage/processor, then we are back to my points.. But look how well Galileo did even with no hi-gain antennea!
The MER rovers are also interesting - part of the problem is lack of computing power. The 1985 style/speed processors do not help - think of the benefits of having decent processor power for compressing image/other data before it is sent..
Thanks, interesting post, although I think now they are replanning to send a big mission to Jupiter (JIMO) instead of a smaller option.
My own belief is that, despite your valid points, you get more data overall with more diverse & less expensive missions, and economies of scale by making many copies of one design. That way for example, two+ orbiters could have been sent (and updated for continous presence) to both Jupiter and Saturn. As things are we tend to have rather too few missions, with very big price tags.
When you look at the disaster that so nearly crippled Galileo (hi gain antenea failure), redundancy matters..
Optics do matter, but it is wrong to say that the sort of quality of optics on this craft would not benefit from a higher resolution CCD.
Make the missions faster & smaller in scale, you turn it around quicker (and more often) & hence deliever more up to date tech for any given timescale..
Cassini missed a launch window due to delays - so it had to take much longer to get to Saturn. If it had gone to plan, it would already be orbiting & taking 1mp photos for a time, and if the budget would have been less we could a launched another follow up with higher resolution cameras.
Smaller, cheaper, faster is better..
I thought one of the things that did come out of "Faster, Better, Cheaper" in the end was New Horizons to Pluto.. The examples I gave illustrated that some teams can do missions at a much lower cost..
This is going to be a fascinating event - however I do have some questions.. The total mission cost is around $4 billion - is this good value for money? For example look at New Horizons, a Jupier/Pluto/KBO mission with a total projected cost of $600 million. I also wonder, given the scale of the mission, if a RTG should have been put on board Huygens so that it could stay longer and observe the Titan environment over a longer time? (Yes I know it could only relay data when Cassini passes by, but that could still be useful..) Listening to thunderstorms is all well and good, and adding a mic is worth doing because its a cheap thing to do in such a system, but what about a lander that spends more time there looking at the chemistry of Titan?
I think that the smaller, cheaper missions return much better scientific return for the money. For instance, most of the function of the proposed $10 billion JIMO mission could be done by a cheaper Europa-only orbiter that would cost less than $1 billion. (See: http://www.spacedaily.com/news/hubble-04p.html ) Also take a look at the SMART-1 ESA mission - less than $100 million for a complete mission featuring many new technologies.
For example the camera on the $4 billion Cassini mission is only 1 megapixel - if we had a larger number of smaller, cheaper missions, would we be there now with a much better imaging system. Cassini had a much delayed launch, so the design was outdated by the time of its launch in 1997. The same mission launched on a later window could have used ion propulsion (SEP/RTG combo) saving weight (1/2 the 4 tons Cassini weight is fuel)
The same thing could happen with JIMO - if NASA spend $10 billion on that, they could forego many other missions, such as a New Horizons II mission, which would give us a chance to look at Uranus (not always a good word to say on Slashdot) with modern instruments, as well as Jupiter & some more KBO's..
Also think about Hubble - is it worth spending $2 billion on a robot to repair the aging telescope, when the same money could buy better new space telescopes.. (see link above)
I dont want to belittle the work of the scientist working on Cassini - it will be a fascinating mission, I just wonder if we could get more return by rejigging the beurocracy.. The X-Prize, New Horizons and SMART-1 prove that more smaller & competitive missions return much more bang-per-buck..
Before you start jumping up and down here,
:-)
Seems to me you are the one doing the jumping..
(Wouldnt we get better performance long-term from a larger number of smaller probes?)
Most of the cost goes into getting to these very far away places and holding enough propellent that you can slow down enough to be captured into orbit after you've been going very fast for a few years. It's not feasible to launch probes to outer planets all the time because you lose the ability to "sling shot" past other planets as a cheap way to pick up a lot of speed. These gravity assist (or more accuratley, angular momentum assist) moves make a little ship go whole heck of a lot faster which means you don't need as much propellent to get you somewhere. You have to go really fast to someplace that several billion miles away in a few years.
Yes, I understand that. In fact its not all that bad - an opportunity to use Jupiter to sling-shot comes round every 13 months. For example, New Horizons will launch Jan 2006 for Pluto, mission cost $600 million. If a second identical probe is built for a follow up around 2008, we can get a fly-by of Uranus and then some more KBO's, for an even smaller cost. Probes like SMART-1 also conserve power by making careful use of other celestial mechanics & tricks - "lunar resonances", check the ESA site. There are "interplanetary highways" that could even provide "free" trips between planets, all be it slowly..
(and hence would have more up-to-date sensors. For example, the CCD on the Cassini camera is only 1 megapixel!)
The way to get better quality pics is NOT to have more pixels but to have better optics. The cameras in the "eyes" of the Mars Exploration Rovers (the pancam) are only about 1 megapixel and they have returned VERY high resolution pics that look great if you have to blow them up 10 times their size. That's because NASA spends a lot of money to use phenomonally good optics. In addition, more megapixels means larger files which requires higher data transfer rates which requires more power to your antenna which means less electricity to do other stuff. (whew)
Even within limited Bandwidth, higher resolution can prove useful - remember Galileo which busted its high gain antenna, and could only send data to earth at a low data rate? It still did 90% of the science it was supposed to do anyway, by careful use of resources.. I am not saying Cassini is not worthwhile - the results are/will be fascinating. I just believe that smaller/cheaper missions turn around faster and actually put up more modern devices within a given timescale..
(I have heard it suggested that most of the useful function of the JIMO $10 billion orbiter could be done with a simpler $1 billion direct-to-europa mission.. And look at New Horizons, with a mission cost less $1 billion, or SMART-1 less than $100 million..)
Dude, compare apples to apples here. SMART-1 is a test of new technology (ion drive) that is meant to see how well it works and if it useable in other missions. It was meant to be a cheap way to get to the moon. You don't need a whole lot of force to get the moon and orbit it if you're willing to wait a few years...like SMART is. To get to Jupiter and then ORBIT it, you have to go very fast to get there, then be strong enough to slow down to be captured into orbit. Then maybe you'd want a few kilos of propellent left to actually move around near Jupiter for a few year. That is a completely different scope than crusing along to the moon for several years or flying by Pluto-Charon before the atmosphere freezes out.
This is not something I am just pulling out of the air here - for example check this article from SpaceDaily. http://www.spacedaily.com/news/hubble-04p.html
We could get to orbit Europa (the main satellite of interest) with a much cheaper mission than JIMO - about 1 billion should do it. In fact, and this is my origin
Because Cassini cost $4 billion.. :-)
- cassini-iss.cfm ISS includes two cameras; a Wide Angle Camera (WAC) and a Narrow Angle Camera (NAC). Each uses a sensitive charge-coupled device (CCD) as its detector. Each CCD consists of a 1,024 square array of pixels, 12 microns on a side. The camera's system allows for many data collection modes, including on-chip data compression. Both cameras are fitted with spectral filters that rotate on a wheel -- to view different bands within the electromagnetic spectrum ranging from 0.2 microns to 1.1 microns.
Good question - in fact there are only 6 replys so far, so I guess people here arent that excited. Also I do sometimes wonder about these big projects - wouldnt we get better performance long-term from a larger number of smaller probes? these can be turned around in a shorter space of time, and hence would have more up-to-date sensors. For example, the CCD on the Cassini camera is only 1 megapixel! (See below)
I have heard it suggested that most of the useful function of the JIMO $10 billion orbiter could be done with a simpler $1 billion direct-to-europa mission.. And look at New Horizons, with a mission cost less $1 billion, or SMART-1 less than $100 million..
From http://saturn.jpl.nasa.gov/spacecraft/instruments
1) Release an O/S ripped off from a competitor, with no copy protection at a low price.
2) Everyone adopts your O/S because it is cheap to buy, or can be copied for free easily.
3) See off all competition, make the API so huge & unweildly that no one can clone it. Patent bits of it to make sure.
4) Stamp down on copying, introduce draconian licensing scheme that ties every copy you sell to one PC, undermining normal rights of purchasers to resell or move O/S to other PCs.
5) Jack up prices.
6)...
7) PROFIT!
..and it was the first probe to successfully test the Interplanetary Superhighway.
I thought Al Gore invented that..
Seriously could a craft with approx the propellant/mass of SMART-1 use this to get to Mars or beyond? I have often though that large groups of cheap identical probes $100 mil like SMART-1 sent by ion propulsion is a much more effective/interesting model for space exploration..
Yes, I am very interested in buying one of these rockets. Tell me, what size warhe.. er.. payload does it carry?
Osama
make it 3 tons of Vodka and I'll go
Make it 3 tons of Vodka, and all of Russia would go..
> six volunteers will depend on a preset limit of supplies, including about 5 tons of food and oxygen and 3 tons of water
But how is that any different from regular russia?
In regular russia, the food and water consume YOU!!!
I remember seeing a doco about it. I think the ship was called "Capricorn 1"..
Fox News anyone?
Coming up on Fox News - Do Democrats cause Cancer?
First raided by the FBI, then /.ed..
Drexler's vision of it is a virus which would eat a skyscraper, a dog, Will Smith, whatever.
Does it have to be that order? Cant we just get it to eat Will Smith?
..which was about 1.5 meters (yards) long..
I didnt know.. That meters and yards were the exact same thing.
The key to this conundrum is held within the word "about"..
Awww! Cute little kitt.. Hey!
I am going to patent the smell of my socks..
If it was possible to make a Nanobot that could turn everything into grey goo, wouldnt everything already be grey goo?
I mean, another civilisation somewhere would have made it, and it would have eaten.. well.. everything..
From the wired article..
"You and people around you have scared our children," Smalley fairly shouted in print. "I don't expect you to stop, but I hope others in the chemical community will join with me in turning on the light and showing our children that, while our future in the real world will be challenging and there are real risks, there will be no such monster as the self-replicating mechanical nanobot of your dreams."
Isnt it called DNA?
Sure its a question of whatever is the most effective. The claim is that direct Hydrogen production/storage is more efficient, but if you have a good battery, do it that way. The current best selling Electric car (UK) does 1.3p/mile compared to 20p/mile for a normal car - but only with 30 mile range on a charge.
My guess is the best solution is hybrid - similar to petro-electric hybrids. Add a small hydrogen engine, so you can run around town off batteries on a cheap overnight charge, but if you need a longer run, tank up on Hydrogen..
It would be much better to just electrolyse off the grid overnight, and use spare off peak power. Then use wind/solar/tide/wave to run the grid - off-peak hydrogen generation helps mke use of unwanted power.. By all means have solar on the car too, it will give you a few free miles every day..
I thought this might be worth posting in its entirety..
From http://www.bwea.com/ref/stop.html
What happens when the wind stops blowing?
Much of the following information is taken from an article by
DJ Milborrow in WindDirections Volume XIV, No.3 April 1995.
Wind turbines generate electricity from a fuel that is free and will never run out, but which isn't available all the time. This factor of 'non-firm' or intermittent' generation is often cited as a detriment of wind energy, with a popular question being 'what happens when the wind stops blowing'. Not a lot really, as electricity continues to be provided by other forms of generation, such as gas or nuclear. Our electricity system is mostly made up of large power stations, and the system has to be able to cope if one of these large plants goes out of action. Equally, the system is well used to dealing with fluctuations in demand, such as millions of people putting the kettle on during commercial breaks of a popular soap on TV!
The fluctuations caused by non-firm generation of electricity from wind turbines are not noticeable above the normal rises and falls in demand on the system. In fact, it is possible to have up to 10% of the country's needs met by intermittent energy sources such as wind energy without having to make any significant changes to the way the system operates.
For more detailed information on how the system operates and what happens when the wind stops blowing, read on.
Is it a problem?
The UK's power system relies on a diverse collection of different types of generation. No individual power plant is 100% reliable, but the system as a whole is very reliable.
There are numerous power stations in the UK. There are around 23 large coal fired plant (some of which also burn some gas or oil), 17 nuclear plants, 8 large oil plants and 11 new combined cycle gas turbines (CCGTs) and several others. Large in this context means over 100MW. (The percentage of generation by fuel type in 1995 was 48% coal, 23% nuclear, 17% CCGT and open cycle gas turbines, 9% interconnectors and 1% oil and the remainder hydro and the new renewables).
Whilst wind still makes up a very small proportion of our total electricity generating capacity coping with the intermittent nature of the wind poses no problem in relation to the other fluctuations in supply and demand which the system copes with. It is very small in comparison with the problems of meeting demand if one large power station is suddenly put out of action.
Even if wind energy capacity rises to 15,000 MW, i.e. enough to meet 13% of the UK's electricity demand during 1994, it would still be a smaller threat than one conventional power station being unexpectedly unavailable.
Putting it into perspective
The other threats to the system, which far outweigh the variability of wind are
* Failure of the cross channel link. The UK is connected to France by two 1000MW circuits which periodically fail. Loss of one circuit occurs more frequently than the loss of both, but neither occurrence causes any significant upset to system operations.
* Steam turbine trips - these occur for many reasons, including false alarms. The largest stets have a rating of 660 MW and, again, the system is managed so that these cause no problems.
* Transformer failures - when these occur on the national grid, significant imbalances can occur and load sometimes needs to be shed as a result.
* Thunderstorms - National Grid network circuits can trip out if struck by lightning.
* Unexpected increases in demand - e.g. dark storm clouds can cause a sudden increase in lighting demand. Most increases in demand are predictable and so pose less of a problem.
The imagined threat due to wind generation is simply not in the same league as any of these occurrences.
The output from a wind farm is smoother than the output from a single machine, and the output from a dispersed win