At large-scale stationary sizes, flow batteries and molten sodium batteries are far more cost effective than lithium. Even lead acid is perfectly feasible and the advantange of that model is that it's almost entirely recyclable at the end fo the device's lifespan (it's about $ per Wh, not about Wh per unit volume or unit mass. Making the battery vault double the size is normally cheaper than using more expensive batteries.)
"Another example is offshore windmills producing compressed air"
Compressed air systems are about the most inefficient form of energy storage I can think of. When you compress gas it heats up and the heat is normally tossed overboard (waste). When you decompress it, energy has to be added to keep it from being too cold (more waste).
The end result is an end-to-end efficiency of a few percent. If the energy is free then that's tolerable, but it's far more more efficient to store the energy as heat or chemically.
However way you do it, energy storage/release systems end up with an end-to-end (as in electrical energy) efficiency of 25-30% at best, which means that in order to have enough continuous capacity you need to substantially overbuild your generation capacity to gather more in during peaks (ie, even hgigher costs)
Mechanical energy storage systems such as compressed air also have to deal with the issue of component stress. If you're storing a few megajoules of energy in a pressure tank's walls you really don't want it developing microfractures due to constant compression/decompression cycles - and it's worth noting that as the size of an air tank increases the engineering complexity goes up exponentially (ie, it might work well in a lab, but can't scale up to commercially viable sizes)
Overhead domestic power distribution is uncommon in the UK except in tiny villages. If you see 4 overhead wires, it's 3-phase domestic delivery (the 3th is neutral)
In general what you'll see is overhead 110/220kV pylons feeding to a substation, which in turn runs 11kW to local transformers that in turn drop 415V 3-phase to nearby houses. Most of the time the LV is underground and sometimes you'll see overhead 11kV to the local transformer.
It's all about economics and how often cars hit poles.
I'm aware of the drawbacks of current nuke tech in hot weather. The reality is that water-cooled nuke plants simply don't get hot enough to be very efficient.
The other reality of watercooled fuel-rod based plants is that you _can't_ turn them up and down much. Doing so results in neutron poisons (primarily xenon) building up quickly and knocking out the reactor's criticality until they break down (which takes hours) - you can turn it down fast but bringing it back up can take a day.
If you use a MSR plant then the hot side can be 700-110C instead of 350C and that in turn means the cold side doesn't need to be water cooled at all (remember all heat engines work by transporting energy from the hot to the cold side) which in turn means that plants don't have to be located next to rivers or the sea
Because MSR systems have the fuel dissolved in the salt, xenon is free to outgas in the circulation pumps's surge chamber where it can be extracted (along with helium and other gasses). That in turn means that MSR plants can more-or-less load-follow.
The shorter version is that judging nuclear plants by current commercial designs (which haven't changed much since they were first developed for submarines in the 1950s) is very shortsighted. MSRs were proven practical 45 years ago but killed for political reasons. In the last decade there's been a resurgence of interest and there's active research going into making sure that corrosion and "freezing" issues are solvable (the salts freeze at ~400C, which means if they escape from the reactor they won't go far and that in conjunction with being unpressurised means that any leak is likely to be self-sealing, but you still don't want anything getting out as it's fiercely radioactive and therefore harmful to anyone in the immediate vicinity)
MSRs can be made with or without Thorium Cycle. The big advantage of using thorium is that it's _cheap_, plentifully available and the byproducts of making reactor fuel can't be used to make H-bombs, plus the waste output of the reactor itself is decreased by at least 90%
Plutonium is a pesky nuisance, but the "right" kind of reactors make plutonium which is utterly useless for bombs and can burn it down in-situ.
It's worth noting that depleted uranium (a necessary byproduct of uranium reactor fuelling) is an essential ingredient of H-bombs - the casing is made of it and the more you use, the higher the yield.
Current Uranium + boiling/pressurised water-based reactor technology was designed for a specific purpose (7-10MW power sources for submarines) and as it's scaled up the problems with containment, etc scale up exponentially with the size. Growing to 1400MW was just silly.
Molten salt systems were demonstrated 45 years ago. Even conventional uranium fuelled setups can use it but adding thorium eliminates the need for "enriching" natural uranium (which is rare and expensive compared to Thorium, plus the enrichment process is obscenely energy intensive and there's the issue of the U238 to consider - thankfully that depleted uranium can also be dumped into a molten salt system)
"A high pressure steam explosion is a nasty thing too"
This is the part which demonstrates why current nuke technology is fundamentally unsuitable for what it's doing. Water and radioactives shouldn't be mixing.
Roll on Molten Salt reactors (Forget Sodium cooling, that's an even barmier idea. Molten sodium and air and not a good combination.)
"not least "hot spots" where contamination levels are higher"
Funnily enough, japanese authorities have been running around the area with scintillation counters finding those hotspots. When they find them, the soil gets bagged, tagged and moved to storage.
Areas like Fukushima have far worse problems than radiation anyway, with a rapidly aging population and steady removal of infrastructure thanks to Japan's 20-year long economic downturn. The japanese population bomb is well and truely happening and it's worth seeing what's happened there, as it's only just starting to happen in the west.
"It's unsuitable for living on, growing food, etc"
Even before the cleanup that "unsuitable land" was still less radioactive than Downtown Helsinki (granite) or Denver (Altitude), let alone what the average japanese citizen gets from smoking (my experience there is that at least 50% of the population are smokers)
There's far too much scaremongering happening. Those "highly contaminated water tanks" are less radioactive than most hot springs as one example.
Fukushima was a power station more than a decade past its design life, with substandard maintenance, that shut down correctly when hit with an earthquake far larger than it was designed for and then got hit by a Tsunami that killed ~30,000 people. Even then the _only_ reason there was an explosion was because pathological fear of "radiation" meant that Tepco violated established procedures and didn't vent the hydrogen which was being generated by overheated cooling water reacting with the dissolved borates.
Even that wouldn't have happened if the Japanese had refused to admit they needed assistance (there were generators ready to go from Okinawa, waiting for an assistance request that never arrived) due to the perceived loss of face this entailed.
It's not even close to being a fuckup on the Chernobyl scale, but a lot of things went wrong and noone's growing an extra arm, or dead. As soon as the principal engineer onsite told incompetent Tepco management to go fuck themselves and took local control of the situation, things improved rapidly.
Given a choice between Fukushima and the Tokyo smogs which used to kill thousands of people every year, it's not even a choice which should have to be made, but apparently Zero deaths from radiation exposure is far more dangerous than thousands from air pollution.
Mostly because the problems are vastly overstated.
The total amount of high level "waste" from an average sized nuke plant over its 60 year operation cycle can be stored in an Olympic-sized swimming pool.
After 300 years it's only slightly radioactive - plutonium may have a 27,000 year half life but it's not particularly radioactive. The hot stuff has 10 day to 20 year half lives.
Compare that with the waste from a coal plant and bear in mind that the _2_ biggest USA environmental disasters this century have been coal tailing pond dam breaks. The Gulf of Mexico BP spill is 3rd.
Almost all domestic distribution (street cabling) is underground in London.
Most High Voltage is overground to a local substation, except in the central parts - that's in an existing tunnel which isn't large enough to handle demands so a new one is being built.
HV cabling tunnels are _large_, due to spacing requirements. These are the kinds of voltages which can reach out and maul you just as badly as the Unseen Library's books, if you're careless.
The fast solution would be for Internexion to buy out the complainers.
Lest you think I'm joking, this is _exactly_ what airports do for their approach paths. Once they own the land that's affected by noise they can tell the tenants to live with it or move out.
> Yes, with proper baffling, it can be brought down to a "low roar"
It can be brought down a lot lower than that. The generators here are _in_ 40 foot cargo containers (along with the flywheel-based UPS system they are part of). The baffling is in additional containers plonked on top.
Japan has several medical hotspots for problems and none of them are radiation related (Hiroshima and Nagasaki have cancer rates 0.25% above background rates).
Minimata is one area where the causual link is well known and researched (mercury dumping in the bay). Other areas have similar single point origins.
Old age is one of the largest "causes" of cancers....:)
One of the main reasons that more people are discovered with cancers after such events is quite simply that medics are actively looking for such things vs "ordinary" circumstances, which is a shame as most cancers triggers are chemical, not radiological (even lung cancers related to polonium are more likely to be from the polonium breakdown products than the alpha radiation)
Along the same lines, the main reason why more people are discovered with cancer these days is simply that more people are living long enough to get cancers in the first place. With a few exceptions we've eliminated almost every other disease that can kill you at a younger age.
Slashdot Mirror
That fourth dimension is ~300 years, not tens of thousands.
No, you're not. Morocco is probably better off buying a few nuke plants.
At large-scale stationary sizes, flow batteries and molten sodium batteries are far more cost effective than lithium. Even lead acid is perfectly feasible and the advantange of that model is that it's almost entirely recyclable at the end fo the device's lifespan (it's about $ per Wh, not about Wh per unit volume or unit mass. Making the battery vault double the size is normally cheaper than using more expensive batteries.)
"Another example is offshore windmills producing compressed air"
Compressed air systems are about the most inefficient form of energy storage I can think of. When you compress gas it heats up and the heat is normally tossed overboard (waste). When you decompress it, energy has to be added to keep it from being too cold (more waste).
The end result is an end-to-end efficiency of a few percent. If the energy is free then that's tolerable, but it's far more more efficient to store the energy as heat or chemically.
However way you do it, energy storage/release systems end up with an end-to-end (as in electrical energy) efficiency of 25-30% at best, which means that in order to have enough continuous capacity you need to substantially overbuild your generation capacity to gather more in during peaks (ie, even hgigher costs)
Mechanical energy storage systems such as compressed air also have to deal with the issue of component stress. If you're storing a few megajoules of energy in a pressure tank's walls you really don't want it developing microfractures due to constant compression/decompression cycles - and it's worth noting that as the size of an air tank increases the engineering complexity goes up exponentially (ie, it might work well in a lab, but can't scale up to commercially viable sizes)
Overhead domestic power distribution is uncommon in the UK except in tiny villages. If you see 4 overhead wires, it's 3-phase domestic delivery (the 3th is neutral)
See http://www.epemag.net/electric... and http://www.practicalmachinist.... - the photo at the top of the latter link is a relatively common site in semi-rural areas of surrey.
In general what you'll see is overhead 110/220kV pylons feeding to a substation, which in turn runs 11kW to local transformers that in turn drop 415V 3-phase to nearby houses. Most of the time the LV is underground and sometimes you'll see overhead 11kV to the local transformer.
It's all about economics and how often cars hit poles.
A few always do, but it's always possible to buy out everyone around them.
I'm aware of the drawbacks of current nuke tech in hot weather. The reality is that water-cooled nuke plants simply don't get hot enough to be very efficient.
The other reality of watercooled fuel-rod based plants is that you _can't_ turn them up and down much. Doing so results in neutron poisons (primarily xenon) building up quickly and knocking out the reactor's criticality until they break down (which takes hours) - you can turn it down fast but bringing it back up can take a day.
If you use a MSR plant then the hot side can be 700-110C instead of 350C and that in turn means the cold side doesn't need to be water cooled at all (remember all heat engines work by transporting energy from the hot to the cold side) which in turn means that plants don't have to be located next to rivers or the sea
Because MSR systems have the fuel dissolved in the salt, xenon is free to outgas in the circulation pumps's surge chamber where it can be extracted (along with helium and other gasses). That in turn means that MSR plants can more-or-less load-follow.
The shorter version is that judging nuclear plants by current commercial designs (which haven't changed much since they were first developed for submarines in the 1950s) is very shortsighted. MSRs were proven practical 45 years ago but killed for political reasons. In the last decade there's been a resurgence of interest and there's active research going into making sure that corrosion and "freezing" issues are solvable (the salts freeze at ~400C, which means if they escape from the reactor they won't go far and that in conjunction with being unpressurised means that any leak is likely to be self-sealing, but you still don't want anything getting out as it's fiercely radioactive and therefore harmful to anyone in the immediate vicinity)
MSRs can be made with or without Thorium Cycle. The big advantage of using thorium is that it's _cheap_, plentifully available and the byproducts of making reactor fuel can't be used to make H-bombs, plus the waste output of the reactor itself is decreased by at least 90%
Yes, it's called NiChrome and it's been around forever.
Plutonium is a pesky nuisance, but the "right" kind of reactors make plutonium which is utterly useless for bombs and can burn it down in-situ.
It's worth noting that depleted uranium (a necessary byproduct of uranium reactor fuelling) is an essential ingredient of H-bombs - the casing is made of it and the more you use, the higher the yield.
Current Uranium + boiling/pressurised water-based reactor technology was designed for a specific purpose (7-10MW power sources for submarines) and as it's scaled up the problems with containment, etc scale up exponentially with the size. Growing to 1400MW was just silly.
Molten salt systems were demonstrated 45 years ago. Even conventional uranium fuelled setups can use it but adding thorium eliminates the need for "enriching" natural uranium (which is rare and expensive compared to Thorium, plus the enrichment process is obscenely energy intensive and there's the issue of the U238 to consider - thankfully that depleted uranium can also be dumped into a molten salt system)
"The problem with waste disposal is not going away any time soon"
1: The hot stuff lasts less than 300 years
2: What's left is usable fuel
3: Breeders can solve that now (the barriers are political, not technical)
"A high pressure steam explosion is a nasty thing too"
This is the part which demonstrates why current nuke technology is fundamentally unsuitable for what it's doing. Water and radioactives shouldn't be mixing.
Roll on Molten Salt reactors (Forget Sodium cooling, that's an even barmier idea. Molten sodium and air and not a good combination.)
"not least "hot spots" where contamination levels are higher"
Funnily enough, japanese authorities have been running around the area with scintillation counters finding those hotspots. When they find them, the soil gets bagged, tagged and moved to storage.
Areas like Fukushima have far worse problems than radiation anyway, with a rapidly aging population and steady removal of infrastructure thanks to Japan's 20-year long economic downturn. The japanese population bomb is well and truely happening and it's worth seeing what's happened there, as it's only just starting to happen in the west.
"It's unsuitable for living on, growing food, etc"
Even before the cleanup that "unsuitable land" was still less radioactive than Downtown Helsinki (granite) or Denver (Altitude), let alone what the average japanese citizen gets from smoking (my experience there is that at least 50% of the population are smokers)
There's far too much scaremongering happening. Those "highly contaminated water tanks" are less radioactive than most hot springs as one example.
Fukushima was a power station more than a decade past its design life, with substandard maintenance, that shut down correctly when hit with an earthquake far larger than it was designed for and then got hit by a Tsunami that killed ~30,000 people. Even then the _only_ reason there was an explosion was because pathological fear of "radiation" meant that Tepco violated established procedures and didn't vent the hydrogen which was being generated by overheated cooling water reacting with the dissolved borates.
Even that wouldn't have happened if the Japanese had refused to admit they needed assistance (there were generators ready to go from Okinawa, waiting for an assistance request that never arrived) due to the perceived loss of face this entailed.
It's not even close to being a fuckup on the Chernobyl scale, but a lot of things went wrong and noone's growing an extra arm, or dead. As soon as the principal engineer onsite told incompetent Tepco management to go fuck themselves and took local control of the situation, things improved rapidly.
Given a choice between Fukushima and the Tokyo smogs which used to kill thousands of people every year, it's not even a choice which should have to be made, but apparently Zero deaths from radiation exposure is far more dangerous than thousands from air pollution.
"still has unsolved fuel storage problems"
Mostly because the problems are vastly overstated.
The total amount of high level "waste" from an average sized nuke plant over its 60 year operation cycle can be stored in an Olympic-sized swimming pool.
After 300 years it's only slightly radioactive - plutonium may have a 27,000 year half life but it's not particularly radioactive. The hot stuff has 10 day to 20 year half lives.
Compare that with the waste from a coal plant and bear in mind that the _2_ biggest USA environmental disasters this century have been coal tailing pond dam breaks. The Gulf of Mexico BP spill is 3rd.
"Wind is not a big hazard to birds"
It's a serious hazard to bats - all they need to do is fly downwind of one and the vortex pressure changes will kill them.
Almost all domestic distribution (street cabling) is underground in London.
Most High Voltage is overground to a local substation, except in the central parts - that's in an existing tunnel which isn't large enough to handle demands so a new one is being built.
HV cabling tunnels are _large_, due to spacing requirements. These are the kinds of voltages which can reach out and maul you just as badly as the Unseen Library's books, if you're careless.
All street cabling in the UK is 400V 3-phase. Each house is normally fed a single phase tap and neutral (rolling taps down the street).
Just because you don't see it doesn't mean it doesn't exist.
The fast solution would be for Internexion to buy out the complainers.
Lest you think I'm joking, this is _exactly_ what airports do for their approach paths. Once they own the land that's affected by noise they can tell the tenants to live with it or move out.
> Yes, with proper baffling, it can be brought down to a "low roar"
It can be brought down a lot lower than that. The generators here are _in_ 40 foot cargo containers (along with the flywheel-based UPS system they are part of). The baffling is in additional containers plonked on top.
"Have you ever seen a MEGA-watt generator?"
Yes. I have two under my control.
Both of them are virtually inaudible unless you're standing within 10 metres. The cooling fans are noisier than the exhaust.
You can have a conversation right next to them without raising your voice. Even there they are quieter than the average idling car.
Paris is geologically stable. They can be underground.
Populated areas have power and connectivity.
Unpopulated areas... not so much.
Japan has several medical hotspots for problems and none of them are radiation related (Hiroshima and Nagasaki have cancer rates 0.25% above background rates).
Minimata is one area where the causual link is well known and researched (mercury dumping in the bay). Other areas have similar single point origins.
Old age is one of the largest "causes" of cancers.... :)
One of the main reasons that more people are discovered with cancers after such events is quite simply that medics are actively looking for such things vs "ordinary" circumstances, which is a shame as most cancers triggers are chemical, not radiological (even lung cancers related to polonium are more likely to be from the polonium breakdown products than the alpha radiation)
Along the same lines, the main reason why more people are discovered with cancer these days is simply that more people are living long enough to get cancers in the first place. With a few exceptions we've eliminated almost every other disease that can kill you at a younger age.
pumped storage is only of use for peak smoothing and generally only has enough capacity for a couple of hours' operation per day.