i agree - while there is economic incentive for providing various types of operating reserve, these are meant to cover the failure of the single biggest unit and transmission line in the area and not growth in demand.
The markets are meant to provide economic incentive for private investors to build power stations, but that means higher prices which makes governments look bad, energy companies look like thieves, and consumers angry.
in ontario, when supply got tight the market operator would lower the reserve requirement to prevent the price from climbing to high. I can't find the citation for this right now, but it is http://www.ieso.ca/imoweb/marketSurveil/mspReports.asp somewhere in there.
Without energy prices high enough to justify the investment, there is no investment.
maybe the power station is geographically remote and economically unfeasible if it has to be manned. maybe it is also economically unfeasible if it has to have an expensive private data connection but can't use a VPN over satellite just fine.
people are going after the 'long tail' of generation with distributed generation such has small/micro hydro, solar etc and I bet a lot of that stuff ends up connected to the internet.
of course a nuclear station shouldn't be on the internet, but maybe a 200kw hydro is?
if you somehow managed to retain an account at your educational institution you may find that they have a subscription to the IEEE and all you have to do is ssh tunnel through your alma matter!
ok,/. won't let me post. does it take ages for everyone else to go from preview to submit?
ok, still waiting to use this resource... cmdrtaco you guys should have this sorted out by now it's only been like... 13 years?
While the privacy commissioner's office had recommended in its report that Facebook have a retention policy specifying how long it will keep information after a user has deactivated his or her account before deleting the information, the office eventually agreed to let Facebook keep the information indefinitely. Denham said Facebook's agreement to provide clarity about the issue is acceptable and in compliance with Canadian law.
Sooooo I guess even deleting your account they still get to keep all your information, pictures, etc.
That is unfortunate and a little unsettling that the information and pictures I have deleted they still own.
I can't believe the govt. backed down on that, it was what I was most looking forward to.
in north america residential service is 120/240. the transformer has a centre tap on the low side. so you get two 120v legs to the centre tap and 240 between the two legs. i think...
I had a BJ60 with 3.4l naturally aspirated 4 cyl and it got 30 MPG and an HJ61 with 4.0l turbo 6 cyl that got 26MPG but was waaaaay faster.
It wasn't the technology in the 80's, it wasn't the fuel in the 80's, it was the american made diesel cars in 80's that gave diesel a bad name in america.
it must have been 14-15 years ago I used to dominate my local quake server because I had a sweet 2.2/1.1 mbps adsl connection and everyone else was on dial up or later 784/128k adsl.
that and my 5 button mouse.
old cpu1673.adsl.bellglobal.com stopped working one day and was so grandfathered nobody knew what the hell it was.
smart grid: has load response (your dishwasher/hotwater/dryer runs when power becomes cheaper) this requires comms from a central authority to your meter to your appliance. as a side benefit (and the main reason for making it happen) the utility can remotely read the meter, and disconnect for non payment or when you move in move out etc
has digital relays instead of electromechanical.
might have more HVDC. this could help with controlling power flows. smart grid might have to deal with less stable sources of power from renewables.
might have more embedded generation, generators within the distribution network as opposed to the transmission network. This generation is close to loads but requires updating of the distribution network to handle reversed power flows and increased complexity.
smart meters are going to make fuck all difference in demand response unless the price of power goes up by about 6x at peak times nobody can be bothered to change their habits. When I'm hot I would pay 10$ an hour to keep the AC on so if it costs 20 cents or a buck twenty i still am cranking that baby up.
On the AC grid I don't think there is much control over where and how power flows - it takes the path of least resistance. power sold in michigan to new york often flows through canada.
With a DC grid exactly how much real and reactive power flows can be totally digitally controlled by the firing times on the valves.
Converting portions of the grid from AC to DC would also be tremendously expensive so I don't see it happening any time soon.
Maybe new transmission lines will be DC, but I don't see many new transmission lines being built either.
15 watts with a power factor of.5 does not mean 30 watts.
it means 15 watts and 25.9 var. Q = P x (tan(arccos(pf)) S = P +jQ so S = 15 +j 25.9 = 30 at 60 degrees kVA.
15 watts at 110V with a power factor of 1, single phase P=IV*cos theta I=.136A
15 watts at 110v with a power factor of.5, I =.27A but you are still only using 15 watts and you are still (as a residential customer) only billed for 15 watts.
That's the deal with power factor; more current for the same power means the infrastructure has to be able to deliver the current required for the apparent power (S in kVA) and not just the real power (P in kW).
not all companies choose to pay out their profits in dividends but some 'nuts and bolts' companies that have steady income but no real growth prospects (say a company that owns a pipeline) might.
the share price may not go up, but you still make money by owning it. these types companies used to have a price to earnings ratio of 8-12.
I believe that AC adapters still draw some power even with no device hooked to it.
yes, they draw some. some devices like televisions can even draw an appreciable amount, like 20 watts.
Your average AC adapter has a transformer to step the voltage down to say 12-18V and then a rectifier to turn it into DC, and probably an inductor after that as a filter to smooth out the left over ripple.
When your AC adapter is plugged in with nothing plugged into the DC side, the transformer will still draw a bit of magnetizing current, but it is fuck all.
I've been scanning all the comments looking for one that actually said something about smart grids. The discussion thus far has been all about wind, nuclear, AC vs DC but nothing about the actual smart grid. I've come late to the discussion and it is so far down the front page probably nobody will read my post anyway, but here I go.
I'm an electrical engineer, I work on power stations, I know all about smart meters, but I really fail to see or understand the smart grid.
FTFA: What's more important is developing a smarter grid. Equipping transmission lines, distribution networks, and electrical appliances in homes and businesses with sensors and controls that can communicate remotely with grid operators could reduce demand for electricity, allow existing lines to handle more electricity, and make it easier to integrate wind and other intermittent renewable-energy technologies.
OK, I get that smart meters that could control load in the home and reduce peak demand and provide a nice little HMI where people could see how much power they were using right in their living room. Problem is, power is too cheap in my eyes nobody is going to give a shit how much it costs to keep the AC on in the middle of the day because it is hot and they want to be cool.
There was a study where they got the people who were the most keen to save energy, the zealots, to participate with smart meters. They could see the price in their home and decide to have dinner later, do the washing later, turn off the AC, etc. For these people, who were selected as the most likely to respond to price signals, it took a 6-fold increase (from $30MWH to 180MWH) before they changed their patterns. So I don't really think the time of use billing in smart meters will make an impact, mostly because politicians won't allow the cost of energy to swing that much throughout the day.
That being said, what if it was all automatic and the smart meter could talk to the dishwasher and the AC and the fridge! Show me ANY appliance that has a zigbee radio and a meter that it can talk to. It is still all pie-in-the sky because these companies can't figure out how to work with eachother to get their products to interoperate. We're still in a big power grab phase where people are pushing their own product to become the standard.
Now what sensors and controls did you want to attach to transmission lines and distribution networks? How are sensors going to allow transmission lines to handle more power? what controls are we missing? Seems like to me like the grid operators and network operators already have more information than they can process with the thousands of points coming in from their scada systems.
As it is, grid operators have little information about real-time conditions on the grid and no control over demand. With a smart grid, power could quickly be rerouted in response to increases and decreases in wind power. Operators would know how hot transmission lines are getting, allowing them to decide with more accuracy how much power they can carry. Also, consumers could program their homes to use less power during times of peak demand, reducing the need for new power plants.
What is real-time. a recent article quotes 4s delay. another said they could get 30 samples per second! what good is that? what good is the information if it arrives 4s sooner? Operating a power system isn't like a video game where a 4s difference in hitting a button matters.
Operators already know how much power flows through any given circuit on the transmission network, right?! All those CTs at every substation all feed into the SCADA system right?! maybe they don't know the temperature of the line but they can guess pretty acurately by the load on it and the temperature of the day. They have open/close control on every circuit.
So here is a feature of the smart grid, power could quickly be rerouted. there is some meat. I wonder how this is achieved as controlling AC power flows is very difficult AFAIK, bu
Slashdot Mirror
hoooooooot pocket!
i can't wait to get an aeron chair again.
i work on some sites that have satellite connections and 800ms on ssh ain't that bad.
i agree - while there is economic incentive for providing various types of operating reserve, these are meant to cover the failure of the single biggest unit and transmission line in the area and not growth in demand.
The markets are meant to provide economic incentive for private investors to build power stations, but that means higher prices which makes governments look bad, energy companies look like thieves, and consumers angry.
in ontario, when supply got tight the market operator would lower the reserve requirement to prevent the price from climbing to high. I can't find the citation for this right now, but it is http://www.ieso.ca/imoweb/marketSurveil/mspReports.asp somewhere in there.
Without energy prices high enough to justify the investment, there is no investment.
the money isn't on the table
clearly you don't live in ontario where everybody gets an extra line on the monthly bill to help pay their part of the old bankrupt monopoly's debt.
30 billion in debt against 10 billion in assets (http://www.electricityforum.com/news/jul03/hydrodebt.html).
maybe they should have paid a bit more attention to the bottom line
maybe the power station is geographically remote and economically unfeasible if it has to be manned. maybe it is also economically unfeasible if it has to have an expensive private data connection but can't use a VPN over satellite just fine.
people are going after the 'long tail' of generation with distributed generation such has small/micro hydro, solar etc and I bet a lot of that stuff ends up connected to the internet.
of course a nuclear station shouldn't be on the internet, but maybe a 200kw hydro is?
if you somehow managed to retain an account at your educational institution you may find that they have a subscription to the IEEE and all you have to do is ssh tunnel through your alma matter!
ok, /. won't let me post. does it take ages for everyone else to go from preview to submit?
ok, still waiting to use this resource... cmdrtaco you guys should have this sorted out by now it's only been like ... 13 years?
are they compatible at N speeds or G speeds though?
those looked like fishing nets to me.
If you were to come across that in the deep ocean there would be loads of fish following it around feasting the mini-eco system that you describe.
If a fisherman comes across a 'floater' like that it is great luck!
what about when it snows at night?
While the privacy commissioner's office had recommended in its report that Facebook have a retention policy specifying how long it will keep information after a user has deactivated his or her account before deleting the information, the office eventually agreed to let Facebook keep the information indefinitely. Denham said Facebook's agreement to provide clarity about the issue is acceptable and in compliance with Canadian law.
Sooooo I guess even deleting your account they still get to keep all your information, pictures, etc.
That is unfortunate and a little unsettling that the information and pictures I have deleted they still own.
I can't believe the govt. backed down on that, it was what I was most looking forward to.
in north america residential service is 120/240. the transformer has a centre tap on the low side. so you get two 120v legs to the centre tap and 240 between the two legs. i think...
like a pool cover?
must be environmentally unfriendly somehow... no longer can convince people that the reservoir is great because they can't boat/fish on it.
one day, when things get dire, they'll take the 20% extra water in the river and power from the generators over recreation maybe.
diesel was given a bad name by the shitty american diesel cars made in the late 70's and early 80s.
The diesel toyota landcruisers made in the 80s were/are awesome.
I had a BJ60 with 3.4l naturally aspirated 4 cyl and it got 30 MPG and an HJ61 with 4.0l turbo 6 cyl that got 26MPG but was waaaaay faster.
It wasn't the technology in the 80's, it wasn't the fuel in the 80's, it was the american made diesel cars in 80's that gave diesel a bad name in america.
it must have been 14-15 years ago I used to dominate my local quake server because I had a sweet 2.2/1.1 mbps adsl connection and everyone else was on dial up or later 784/128k adsl.
that and my 5 button mouse.
old cpu1673.adsl.bellglobal.com stopped working one day and was so grandfathered nobody knew what the hell it was.
Loads are also becoming more and more non linear and contributing to harmonics on the network further decreasing distribution efficiencies.
smart grid:
has load response (your dishwasher/hotwater/dryer runs when power becomes cheaper)
this requires comms from a central authority to your meter to your appliance. as a side benefit (and the main reason for making it happen) the utility can remotely read the meter, and disconnect for non payment or when you move in move out etc
has digital relays instead of electromechanical.
might have more HVDC. this could help with controlling power flows. smart grid might have to deal with less stable sources of power from renewables.
might have more embedded generation, generators within the distribution network as opposed to the transmission network. This generation is close to loads but requires updating of the distribution network to handle reversed power flows and increased complexity.
none of this stuff is really new...
HVDC is really the key to the smart grid I think.
smart meters are going to make fuck all difference in demand response unless the price of power goes up by about 6x at peak times nobody can be bothered to change their habits. When I'm hot I would pay 10$ an hour to keep the AC on so if it costs 20 cents or a buck twenty i still am cranking that baby up.
On the AC grid I don't think there is much control over where and how power flows - it takes the path of least resistance. power sold in michigan to new york often flows through canada.
With a DC grid exactly how much real and reactive power flows can be totally digitally controlled by the firing times on the valves.
Converting portions of the grid from AC to DC would also be tremendously expensive so I don't see it happening any time soon.
Maybe new transmission lines will be DC, but I don't see many new transmission lines being built either.
15 watts with a power factor of .5 does not mean 30 watts.
it means 15 watts and 25.9 var.
Q = P x (tan(arccos(pf))
S = P +jQ
so S = 15 +j 25.9 = 30 at 60 degrees kVA.
15 watts at 110V with a power factor of 1, single phase
P=IV*cos theta I=.136A
15 watts at 110v with a power factor of .5, I = .27A but you are still only using 15 watts and you are still (as a residential customer) only billed for 15 watts.
That's the deal with power factor; more current for the same power means the infrastructure has to be able to deliver the current required for the apparent power (S in kVA) and not just the real power (P in kW).
not all companies choose to pay out their profits in dividends but some 'nuts and bolts' companies that have steady income but no real growth prospects (say a company that owns a pipeline) might.
the share price may not go up, but you still make money by owning it. these types companies used to have a price to earnings ratio of 8-12.
I believe that AC adapters still draw some power even with no device hooked to it.
yes, they draw some. some devices like televisions can even draw an appreciable amount, like 20 watts.
Your average AC adapter has a transformer to step the voltage down to say 12-18V and then a rectifier to turn it into DC, and probably an inductor after that as a filter to smooth out the left over ripple.
When your AC adapter is plugged in with nothing plugged into the DC side, the transformer will still draw a bit of magnetizing current, but it is fuck all.
See http://en.wikipedia.org/wiki/Transformer#Equivalent_circuit
I think magnetizing current might be 1% tops, so for your 60W laptop power pack you are talking .6 watts.
Even adding up all your power packs you are talking tens of watts.
at $0.30 a for 1000 watts for an hour, those power packs being plugged in is costing you next to zero.
The mess is one thing, but don't worry about the power.
http://en.wikipedia.org/wiki/Circular_mil
TFA says it is a 356 volt system that charges at 1000 amps.
a 500mcm aluminum conductor should move 1000A just fine.
from TFA the batteries alone are 80k and require 1000A at 356 volts for the 'rapid charge'. That is 356 kW.
I've been scanning all the comments looking for one that actually said something about smart grids. The discussion thus far has been all about wind, nuclear, AC vs DC but nothing about the actual smart grid. I've come late to the discussion and it is so far down the front page probably nobody will read my post anyway, but here I go.
I'm an electrical engineer, I work on power stations, I know all about smart meters, but I really fail to see or understand the smart grid.
FTFA:
What's more important is developing a smarter grid. Equipping transmission lines, distribution networks, and electrical appliances in homes and businesses with sensors and controls that can communicate remotely with grid operators could reduce demand for electricity, allow existing lines to handle more electricity, and make it easier to integrate wind and other intermittent renewable-energy technologies.
OK, I get that smart meters that could control load in the home and reduce peak demand and provide a nice little HMI where people could see how much power they were using right in their living room. Problem is, power is too cheap in my eyes nobody is going to give a shit how much it costs to keep the AC on in the middle of the day because it is hot and they want to be cool.
There was a study where they got the people who were the most keen to save energy, the zealots, to participate with smart meters. They could see the price in their home and decide to have dinner later, do the washing later, turn off the AC, etc. For these people, who were selected as the most likely to respond to price signals, it took a 6-fold increase (from $30MWH to 180MWH) before they changed their patterns. So I don't really think the time of use billing in smart meters will make an impact, mostly because politicians won't allow the cost of energy to swing that much throughout the day.
That being said, what if it was all automatic and the smart meter could talk to the dishwasher and the AC and the fridge! Show me ANY appliance that has a zigbee radio and a meter that it can talk to. It is still all pie-in-the sky because these companies can't figure out how to work with eachother to get their products to interoperate. We're still in a big power grab phase where people are pushing their own product to become the standard.
Now what sensors and controls did you want to attach to transmission lines and distribution networks? How are sensors going to allow transmission lines to handle more power? what controls are we missing?
Seems like to me like the grid operators and network operators already have more information than they can process with the thousands of points coming in from their scada systems.
As it is, grid operators have little information about real-time conditions on the grid and no control over demand. With a smart grid, power could quickly be rerouted in response to increases and decreases in wind power. Operators would know how hot transmission lines are getting, allowing them to decide with more accuracy how much power they can carry. Also, consumers could program their homes to use less power during times of peak demand, reducing the need for new power plants.
What is real-time. a recent article quotes 4s delay. another said they could get 30 samples per second! what good is that? what good is the information if it arrives 4s sooner? Operating a power system isn't like a video game where a 4s difference in hitting a button matters.
Operators already know how much power flows through any given circuit on the transmission network, right?! All those CTs at every substation all feed into the SCADA system right?! maybe they don't know the temperature of the line but they can guess pretty acurately by the load on it and the temperature of the day. They have open/close control on every circuit.
So here is a feature of the smart grid, power could quickly be rerouted. there is some meat. I wonder how this is achieved as controlling AC power flows is very difficult AFAIK, bu