I have actually lived for a short time in an experimental solar/wind powered "village" - it is possible, if you are prepared to look at your consumption.
There are individual solar houses that have been built in places like Australia with zero energy bills (net) - but thet are connected to the grid, sometimes they use electricity, sometimes they pump it back to the grid.
It makes sense for new-build properties to incorperate solar into areas like the roof, which would otherwise just be unused..
RTFA:-) These towers do not use cells - they use convection to generate air-flow through 1km high towers that turns 250MW turbines..
Actually Solar cells will become feasable too as oil pushes >$50/barrel.. You would only need to cover part the deserts of australia with solar to make all the worlds electricity.
Bio is interesting, although figures I have seen require planting most the worlds arable land to make enough fuel for the USA - and then you need to power all the trators that plant/harvest etc.. Anyone prove me wrong on that?
No. I didnt argue with your mathematics - I was aware that power generation is proportional to the square of the wind velocity, at least with current generation mills. My point is that in practice it has been found that wind power is far more consistant than first feared - if you have a reasonable sized grid, and the variability drops as the grid gets larger. See http://www.bwea.com/ref/stop.html - the suggest 13% not as an absolute maximum, but what could be integrated easily without big changes. Newer data (ie from operational farms in Hawaii) suggest this figure could be larger still. Note that 2 gw of pumped hydro reserve can drop in/out within 15 seconds! If you can increase that..
Also my suggestion was to use generation of hydrogen as a method of evening peaks & using surplus off-peak power. Certainly to go to 50-100% alt energy product requires changes to our energy system & grids - but the technology is there..
outages for coal and nuclear plants are typically scheduled months in advance.
Outages on lines to these stations however are unpredictable and not so rare, so a reserve must be kept operational.
Also from the FAQ: An average for a new onshore wind farm in a good location is 3-4 pence per unit, competitive with new coal (2.5-4.5p) and cheaper than new nuclear (4-7p). Much cheaper when you consider all the pollutants that those other fuels generate..
Now the question is, do the people who live off the grid still drive to work with gasoline fueled cars? A typical car uses over 100 KW of power. For a 30 minute trip at 50 KW (not full power), you would need almost 42 batteries to get there!
As I said, going Nuclear doesnt solve this problem you still need to tackle the problem of storage/conversion for cars, whether the electricity comes from Wind or Nuclear. The best selling Electric car can run you around town for about 1.3p/mile, compared to 20p/mile for a normal petrol car (UK prices). Of course, maybe only 30-60 miles per charge, so what happens for longer trips? Add a small Hydrogen engine - so you can use cheap off-peak electricity for running about town, or Hydrogen for longer runs..
a 40 MW silicon refining plant outside my hometown would need to use 40,000 car batteries!
I dont agree with your original supposition - resourses like wind, solar, etc are quite widely distributed. However, in the long term we may see certain types of very power-hungry production relocated to places where power is the most plentiful - ie aluminium production is often located next to a hydro-electric plant, etc..
In the end, market economics can be used - so if you can pay $50/barrel + carbon tax & make your power hungry factory compete against another located close to a gigawatt solar tower/wind farm/tidal barrage, fair enough..
Calculations can show that an ideal (no friction in parts) wind generator has a power to surface area ratio equal to 8/27 of the density of air times the cube of the wind velocity. This means that a 20% reduction is the wind velocity will lead to roughly a 50% reduction in power output from a given wind plant. For this reason alone it should be obvious that wind plants are only useful for reducing the load of other plants (as long as they can come back up to full capacity or have peaking plants standing by). By no means can wind be only energy generator for an area.
Not true. Check out the faq on the British Wind Energy Association page - in practice, on a large grid, the "averaging" process means that variability in wind-power is much less of a problem than originally envisaged - the wind is always blowing somewhere, and there are sites with pretty constant, strong winds. It is also a myth that other sources are "reliable" - outages from traditional Coal/Gas/Nuclear plants (or the power lines to them) are common, and have to be catered for. In reality keeping a "stable" grid is a complex balancing act - keeping a minimum spinning reserve for possible outages.
In practice, however, we could have 200%+ of our energy need from offshore wind - and the USA has similar (largely unsurveyed) potentials. But, what do you do with all that excess off-peak power? Turn it into Hydrogen to run cars, and/or use off-peak power to charge car batteries.
Remember, going Nuclear doesnt solve one of the biggest problems - replacing polluting petrol car engines - you still need to tackle the problem of storage/conversion for cars. That problem remains the same, whether the electricity comes from Wind or Nuclear..
Coal can be Black or maybe Brown, but never Green..
But seriously, there is now a massive power struggle for power - all the different interest groups are jockeying for position to be the next big "green" fuel.
My own 2c (per kw/hour) is that the very simple obvious non-polluting green alternatives - wind, tide, wave, solar, etc - have quietly evolved to a stage where they could take over as the western worlds main source of energy. Why do we need to mess around with nuclear/coal/oil? All the supporting technologies have developed sufficiently that they are either already economical, or at worse should be soon with a little more work. If you just take wind alone, the latest batch of offshore wind farms are contracted to supply power to the UK grid at 0.03 pounds/kilowatt/hour - pretty competitive, and set to come down with scale. (British Wind Energy Association page)(American Wind Energy Association page)
The latest windmills do not present loading problems for the grid, probably kill less wildlife than other things (ie tall structures in general, glass windows, cars, oil rigs etc..) & do not really mess up the landscape for 99.99% of people.
The UK alone has many times its energy needs already available in potential off-shore sites. The USA and Australia have similar huge (and worryingly largely unsurveyed) potentials - off & on shore.
And then you can look at other sources - tide, wave, solar.. For instance, Australia is building 1 km high towers that can generate power by solar power.
Ok, back to coal - can it be green? Well if you can safely bury 100% (or close to) emmissions - dont forget all the other by-products (CO, SO2, mercury, lead.. ) and you mine it in a green manner, you would have something resembling a green source of power for a short while - until all the easily minable resources were gone, then renewables become cheaper anyway..
Nuclear? Oh sure its "cheap" - until you have to decommission the sites, and get rid of the waste safely - which has to be looked after for centuries.. Billions of pounds were wasted on Nuclear power generation in the UK to no avail - the money would have been much better spent on researching renewables, which have had a pittance by comparison.
They cant do that, at least easily - the roll-while-imaging method only works if you know the area you want to look at exactly - it would take way to long to search the possible area for beagle impact. Maybe they should have timed beagle eta better so that MGS could image impact..
'You asked me once,' said O'Brien, 'what was in Room 101. I told you that you knew the answer already. Everyone knows it. The thing that is in Room 101 is the worst thing in the world.'
The door opened again. A guard came in, carrying something made of wire, a box or basket of some kind. He set it down on the further table. Because of the position in which O'Brien was standing. Winston could not see what the thing was.
'The worst thing in the world,' said O'Brien, 'varies from individual to individual. It may be burial alive, or death by fire, or by drowning, or by impalement, or fifty other deaths. There are cases where it is some quite trivial thing, not even fatal.'
He had moved a little to one side, so that Winston had a better view of the thing on the table. It was an oblong wire cage with a handle on top for carrying it by. Fixed to the front of it was something that looked like a fencing mask, with the concave side outwards. Although it was three or four metres away from him, he could see that the cage was divided lengthways into two compartments, and that there was some kind of creature in each. They were rats.
'In your case,' said O'Brien, 'the worst thing in the world happens to be rats.'
May not even be that necessary, since there are enough on/off-shore sites to supply many times our electricity needs from wind - and in fact real-life usage has shown wind power is much more constant/reliable than first supposed. Just make sure that we have "oversupply", and yes, use the spare to make hydrogen fuel for cars, or store by pumping at hydro electric plants..
It has been estimated that 1 billion birds a year are killed by.. glass! Pretty much all tall structures cause some level of bird-deaths. *Every* power option has an environmental impact - it may be something we all have to accept as a cost of cheap clean power..
There was an interesting article on spacedaily.com (The case against Hubble) which proposes that 2 new cheaper modern telescopes could be built for the price of "repairing" hubble.. I was in favour, until I heard about the costs.. Its had a damn good run, and will continue to do good science, but its like an old car that is costing more and more to put through its MOT each year..
Slashdot Mirror
I have actually lived for a short time in an experimental solar/wind powered "village" - it is possible, if you are prepared to look at your consumption.
There are individual solar houses that have been built in places like Australia with zero energy bills (net) - but thet are connected to the grid, sometimes they use electricity, sometimes they pump it back to the grid.
It makes sense for new-build properties to incorperate solar into areas like the roof, which would otherwise just be unused..
RTFA :-)
These towers do not use cells - they use convection to generate air-flow through 1km high towers that turns 250MW turbines..
Actually Solar cells will become feasable too as oil pushes >$50/barrel.. You would only need to cover part the deserts of australia with solar to make all the worlds electricity.
Bio is interesting, although figures I have seen require planting most the worlds arable land to make enough fuel for the USA - and then you need to power all the trators that plant/harvest etc.. Anyone prove me wrong on that?
No. I didnt argue with your mathematics - I was aware that power generation is proportional to the square of the wind velocity, at least with current generation mills. My point is that in practice it has been found that wind power is far more consistant than first feared - if you have a reasonable sized grid, and the variability drops as the grid gets larger. See http://www.bwea.com/ref/stop.html - the suggest 13% not as an absolute maximum, but what could be integrated easily without big changes. Newer data (ie from operational farms in Hawaii) suggest this figure could be larger still. Note that 2 gw of pumped hydro reserve can drop in/out within 15 seconds! If you can increase that..
Also my suggestion was to use generation of hydrogen as a method of evening peaks & using surplus off-peak power. Certainly to go to 50-100% alt energy product requires changes to our energy system & grids - but the technology is there..
outages for coal and nuclear plants are typically scheduled months in advance.
Outages on lines to these stations however are unpredictable and not so rare, so a reserve must be kept operational.
Also from the FAQ: An average for a new onshore wind farm in a good location is 3-4 pence per unit, competitive with new coal (2.5-4.5p) and cheaper than new nuclear (4-7p). Much cheaper when you consider all the pollutants that those other fuels generate..
Now the question is, do the people who live off the grid still drive to work with gasoline fueled cars? A typical car uses over 100 KW of power. For a 30 minute trip at 50 KW (not full power), you would need almost 42 batteries to get there!
As I said, going Nuclear doesnt solve this problem you still need to tackle the problem of storage/conversion for cars, whether the electricity comes from Wind or Nuclear. The best selling Electric car can run you around town for about 1.3p/mile, compared to 20p/mile for a normal petrol car (UK prices). Of course, maybe only 30-60 miles per charge, so what happens for longer trips? Add a small Hydrogen engine - so you can use cheap off-peak electricity for running about town, or Hydrogen for longer runs..
a 40 MW silicon refining plant outside my hometown would need to use 40,000 car batteries!
I dont agree with your original supposition - resourses like wind, solar, etc are quite widely distributed. However, in the long term we may see certain types of very power-hungry production relocated to places where power is the most plentiful - ie aluminium production is often located next to a hydro-electric plant, etc..
In the end, market economics can be used - so if you can pay $50/barrel + carbon tax & make your power hungry factory compete against another located close to a gigawatt solar tower/wind farm/tidal barrage, fair enough..
Calculations can show that an ideal (no friction in parts) wind generator has a power to surface area ratio equal to 8/27 of the density of air times the cube of the wind velocity. This means that a 20% reduction is the wind velocity will lead to roughly a 50% reduction in power output from a given wind plant. For this reason alone it should be obvious that wind plants are only useful for reducing the load of other plants (as long as they can come back up to full capacity or have peaking plants standing by). By no means can wind be only energy generator for an area.
Not true. Check out the faq on the British Wind Energy Association page - in practice, on a large grid, the "averaging" process means that variability in wind-power is much less of a problem than originally envisaged - the wind is always blowing somewhere, and there are sites with pretty constant, strong winds. It is also a myth that other sources are "reliable" - outages from traditional Coal/Gas/Nuclear plants (or the power lines to them) are common, and have to be catered for. In reality keeping a "stable" grid is a complex balancing act - keeping a minimum spinning reserve for possible outages.
In practice, however, we could have 200%+ of our energy need from offshore wind - and the USA has similar (largely unsurveyed) potentials. But, what do you do with all that excess off-peak power? Turn it into Hydrogen to run cars, and/or use off-peak power to charge car batteries.
Remember, going Nuclear doesnt solve one of the biggest problems - replacing polluting petrol car engines - you still need to tackle the problem of storage/conversion for cars. That problem remains the same, whether the electricity comes from Wind or Nuclear..
Butterfingers!
Coal can be Black or maybe Brown, but never Green..
But seriously, there is now a massive power struggle for power - all the different interest groups are jockeying for position to be the next big "green" fuel.
My own 2c (per kw/hour) is that the very simple obvious non-polluting green alternatives - wind, tide, wave, solar, etc - have quietly evolved to a stage where they could take over as the western worlds main source of energy. Why do we need to mess around with nuclear/coal/oil? All the supporting technologies have developed sufficiently that they are either already economical, or at worse should be soon with a little more work. If you just take wind alone, the latest batch of offshore wind farms are contracted to supply power to the UK grid at 0.03 pounds/kilowatt/hour - pretty competitive, and set to come down with scale. (British Wind Energy Association page) (American Wind Energy Association page)
The latest windmills do not present loading problems for the grid, probably kill less wildlife than other things (ie tall structures in general, glass windows, cars, oil rigs etc..) & do not really mess up the landscape for 99.99% of people.
The UK alone has many times its energy needs already available in potential off-shore sites. The USA and Australia have similar huge (and worryingly largely unsurveyed) potentials - off & on shore.
And then you can look at other sources - tide, wave, solar.. For instance, Australia is building 1 km high towers that can generate power by solar power.
Ok, back to coal - can it be green? Well if you can safely bury 100% (or close to) emmissions - dont forget all the other by-products (CO, SO2, mercury, lead.. ) and you mine it in a green manner, you would have something resembling a green source of power for a short while - until all the easily minable resources were gone, then renewables become cheaper anyway..
Nuclear? Oh sure its "cheap" - until you have to decommission the sites, and get rid of the waste safely - which has to be looked after for centuries.. Billions of pounds were wasted on Nuclear power generation in the UK to no avail - the money would have been much better spent on researching renewables, which have had a pittance by comparison.
What if it lands in dogshit?
Not a problem, just consider it extra protein & flavour..
Here is an ascii representation of the encounter..
.
(Just scroll down & blink quickly)
.
o
o
O
O - closest encounter
O
o
o
Not mushroom left in that forest, then..
Im hanging out for the 4Tb DVD-R. When it hits 50 quid..
Or you mean Slartibartfast?
They cant do that, at least easily - the roll-while-imaging method only works if you know the area you want to look at exactly - it would take way to long to search the possible area for beagle impact. Maybe they should have timed beagle eta better so that MGS could image impact..
'You asked me once,' said O'Brien, 'what was in Room 101. I told you that you knew the answer already. Everyone knows it. The thing that is in Room 101 is the worst thing in the world.'
The door opened again. A guard came in, carrying something made of wire, a box or basket of some kind. He set it down on the further table. Because of the position in which O'Brien was standing. Winston could not see what the thing was.
'The worst thing in the world,' said O'Brien, 'varies from individual to individual. It may be burial alive, or death by fire, or by drowning, or by impalement, or fifty other deaths. There are cases where it is some quite trivial thing, not even fatal.'
He had moved a little to one side, so that Winston had a better view of the thing on the table. It was an oblong wire cage with a handle on top for carrying it by. Fixed to the front of it was something that looked like a fencing mask, with the concave side outwards. Although it was three or four metres away from him, he could see that the cage was divided lengthways into two compartments, and that there was some kind of creature in each. They were rats.
'In your case,' said O'Brien, 'the worst thing in the world happens to be rats.'
Hello, is that ComReg? I would like my aunties number to added to ther white list. The number is +475 5746353735373..
Why am I not suprised?
$150k says thats the way it stays..
They come with their own letters of authenticity.
And what about those letters?
May not even be that necessary, since there are enough on/off-shore sites to supply many times our electricity needs from wind - and in fact real-life usage has shown wind power is much more constant/reliable than first supposed. Just make sure that we have "oversupply", and yes, use the spare to make hydrogen fuel for cars, or store by pumping at hydro electric plants..
(British Wind Energy Association page)
(American Wind Energy Association page)
It has been estimated that 1 billion birds a year are killed by.. glass! Pretty much all tall structures cause some level of bird-deaths. *Every* power option has an environmental impact - it may be something we all have to accept as a cost of cheap clean power..
(British Wind Energy Association page)
(American Wind Energy Association page)
As far as I understand, there have not been signals recieved from Pioneer-10 since Jan 2003..
http://nssdc.gsfc.nasa.gov/nmc/tmp/1972-012A.html
So, has a new signal been recieved, or is this just new analysis of old data?
Damn you, Darl McBride! Damn your eyes!
Faster switching == more power needed? Not good for laptops..
There was an interesting article on spacedaily.com (The case against Hubble) which proposes that 2 new cheaper modern telescopes could be built for the price of "repairing" hubble.. I was in favour, until I heard about the costs.. Its had a damn good run, and will continue to do good science, but its like an old car that is costing more and more to put through its MOT each year..
Similar to what motivated Voyager scientists to attach a plaque for the outbound trip.
h tml
That link in the header is for the Pioneer plaque, not the Voyager golden record..
http://voyager.jpl.nasa.gov/spacecraft/goldenrec.