I didn't say "open" I said "public". Her are some possible projects; IRS tax system, Stock Exchange system, Telephone switching network, etc.
I am basically calling into question the poster's assertion that he has worked on systems that have taken a decade to implement. Maybe a few years to implement and many more years to add features and debug but probably not a decade before being deployed. There are very few systems as big as the US air traffic control system And very few of those have been recently replaced.
I am not talking about a high capacity solar plant. I am talking about a large numbers of houses with PVs on the roof which may or may not inject electricity into the grid. See the difference?
No it isn't. Every "input" is connected to the grid with safeguards to cut itself off in case of need.
When thousands decide to cut themselves off at the same time there could be problems. There needs to be central control to decide who is cut off. That does not yet exist and will take time, technology and money to introduce.
Parts of the grid above that frequency get automatically disconnected from the rest of the grid.
Where do these disconnections take place? I would bet at a substation. If it is there then many houses would be effected by a disconnection.
You are looking at the grid like it is now with a few inputs and many drains. With few inputs it is simple to cut off the offenders. It is very different when thousands of small producers are added to the mix. With thousands of inputs it is much more difficult to cut of just the right ones.
Here is an interesting quote from the first report;
Distributed PV contributes less variability to the grid, but it presents a challenge in high-penetration scenarios (in the absence of a smart grid) because of the inability of the utility to curtail its power production, which results in less flexibility for grid operators.
The study even admits it is incomplete
Although reliability challenges increase with increasing levels of variable renewable generation, this study found those challenges are manageable from the standpoint of the bulk power system for the scenarios studied with the mitigation approaches recommended. Note that this study did not look at the capital costs for the higher renewable energy scenarios or the mitigation strategies. It also did not assess the integration issues at the distribution level of the power systems.
If you read that paper you will see that there are ways to integrate solar into the grid. The issue is that those methods require modifications and equipment to implement. How much will those changes cost? Who should pay for those changes?
The study even points toward the need for more studies;
The insights from the Hawaii Solar Integration Study form a large body of knowledge for future grid integration studies, and the results can be used to further our understanding of grid integration in other island systems as well as in mainland U.S. systems with high regional solar and wind penetrations.
The second article is about connecting three grids and little if anything about the impact of solar on the grid
The last article is a complaint and does not prove anything. Here is the entire article;
Maui homeowners and photovoltaic system installers are expressing frustration at requirements that they pay for expensive "interconnection studies" before installing solar panels, with no guarantee that their project will be approved after the study is complete.
There is no reference to how much an interconnection study costs. Here is a better explanation about what an interconnection requirements study (IRS) is and what it is necessary in certain instances. An IRS looks into the local grid capacity to handle the input of electricity from the new installation and whether or not local upgrades would be required to accommodate it. Note that an IRS is only required when there is a lot of solar already on the local grid.
Note that the first two articles deal with much higher level grid issues and not local grids.
Look at the current policy from Hawaiian Electric. Notice that IRS's are only required if DML is >250%. They may be required at lower levels depending on the age and capability of the local grid.
I fail to see how any of this supports the statement that interconnect study requirement is unnecessary,
Sorry but posting a few links to article with the words "Hawaii", "grid" and "integration" is not research.
That is how the grid works now. What will happen of a large percentage no longer comes from dispatchable plants but instead from roof top PVs scattered all over the place?
Do you have any references that back up that statement?
How about you do some reading on grid complexity. Managing a grid is very akin to juggling many different inputs and outputs so the supply closely matches the demand. Our electricity system only works in a very narrow range of voltage and frequency. Go outside of those parameters and failures occur.
Over supply is handled by increasing the frequency and therefore the power capacity of the power line. Increase the frequency too much and electrical units can have problems. If a piece of equipment is expecting 60Hz and is getting 65Hz or 70Hz it may be damaged.
but we seem to be moving toward an era of self-generation as a primary source of power
Anyone who lived in a multi-story building will not be self generating. While self generation might be good for some sub-urban and rural areas there is no way it will suffice for urban areas. Therefore the grid will always be needed.
Your hot water analogy is way off considering that a day's worth of PV power may not even last part of a day. That would not be good if your refrigerator only worked part of the day or your computers used for work did the same.
Spoken by someone who truly does not understand how unstable an electric grid really is. If there is more power injected into the grid than there is demand very bad things happen.
McDonalds claims their customers like the coffee at a higher temp (175-180) since they often commute and don't drink it for a while.
I guess you don't commute either. Most people who get coffee at a drive through start drinking it immediately. From the article;
Other establishments sell coffee at substantially lower temperatures, and coffee served at home is generally 135 to 140 degrees. Further, McDonalds' quality assurance manager testified that the company actively enforces a requirement that coffee be held in the pot at 185 degrees, plus or minus five degrees. He also testified that a burn hazard exists with any food substance served at 140 degrees or above, and that McDonalds coffee, at the temperature at which it was poured into styrofoam cups, was not fit for consumption because it would burn the mouth and throat. The quality assurance manager admitted that burns would occur, but testified that McDonalds had no intention of reducing the "holding temperature" of its coffee.
That is an admission of guilt and recklessness by McDonald's, They finally changed their policy
Post-verdict investigation found that the temperature of coffee at the local Albuquerque McDonalds had dropped to 158 degrees fahrenheit.
Similarly, I also don't blame knives for being "too sharp" when I drop one on my foot...
You miss the point that a sharp knife will not cause damage if used correctly. Coffee at 180 degrees would burn the mouth of consumed.
This might be one of the reasons that Tim Horton's actually puts in the cream and sugar so you don't have to on the car.
You are saying even if they felt like they didn't do anything wrong,
There is the rub. They knew they were doing something wrong and did it anyway. They knew they were brewing coffee too hot as they had been warned several times before. They brew hotter so more flavour is extracted and less ground coffee needs to be used. One of the reasons the award was so bit gas that they put a few dollars profit above customer safety. Serving coffe at a temperature that would burn the inside of the mouth when it is designed to be consumed immediately is what got them into trouble.
But on the other hand I (and most people) brew coffee at > 180 degrees at home every day and manage not to soak cotton sweatpants with it to cook our skin for 30 seconds.
I bet that you cool the coffee with milk, as she was trying to do, or wait until you drink it. Coffee that hot would burn your mouth.
Which I have to say, I don't pity them much for. But I also don't think the lawsuit made much sense.
Read a few more facts and you will see that justice was served.
If you imagine shooting an arrow at a wooden ball, unless you hit dead center, it’ll ricochet.
Being crushed between two icebergs is not a point force. A closer analogy would be a ping pong ball between two large blocks of wood. The ball gets crushed.
Therefore disseminating information about where you can download something is speech.
I agree that disseminating information is protected speech. I do not agree that disseminating the copy written property of someone else is protected speech.
The moment you start deciding that one thing is speech and another isn't, regardless of your personal views on the merits of that speech, you begin running headlong towards despotism.
Actually you begin running headlong toward a civil society. Hate speech, incite to riot, libel, slander, etc are not protected speech. These types of speech have been found to be detrimental to civil society and have been made illegal in most places. Just because something is auditory in nature does not make it protected speech.
Slashdot Mirror
I didn't say "open" I said "public". Her are some possible projects; IRS tax system, Stock Exchange system, Telephone switching network, etc.
I am basically calling into question the poster's assertion that he has worked on systems that have taken a decade to implement. Maybe a few years to implement and many more years to add features and debug but probably not a decade before being deployed. There are very few systems as big as the US air traffic control system And very few of those have been recently replaced.
I have had projects take as much as a decade.
If you have had projects that have taken as much as a decade then name a couple. If they were that big I bet that are not confidential.
I am not talking about a high capacity solar plant. I am talking about a large numbers of houses with PVs on the roof which may or may not inject electricity into the grid. See the difference?
Do you have anything to back that up? As far as I know the connection to the grid from a net zero house is exactly the same as a consuming house.
No it isn't. Every "input" is connected to the grid with safeguards to cut itself off in case of need.
When thousands decide to cut themselves off at the same time there could be problems. There needs to be central control to decide who is cut off. That does not yet exist and will take time, technology and money to introduce.
Parts of the grid above that frequency get automatically disconnected from the rest of the grid.
Where do these disconnections take place? I would bet at a substation. If it is there then many houses would be effected by a disconnection.
You are looking at the grid like it is now with a few inputs and many drains. With few inputs it is simple to cut off the offenders. It is very different when thousands of small producers are added to the mix. With thousands of inputs it is much more difficult to cut of just the right ones.
Here is an interesting quote from the first report;
Distributed PV contributes less variability to the grid, but it presents a challenge in high-penetration scenarios (in the absence of a smart grid) because of the inability of the utility to curtail its power production, which results in less flexibility for grid operators.
The study even admits it is incomplete
Although reliability challenges increase with increasing levels of variable
renewable generation, this study found those challenges are manageable from the standpoint of the bulk power system for the scenarios studied with the mitigation approaches recommended. Note that this study did not look at the capital costs for the higher renewable energy scenarios or the mitigation strategies. It also did not assess the integration issues at the distribution level of the power systems.
If you read that paper you will see that there are ways to integrate solar into the grid. The issue is that those methods require modifications and equipment to implement. How much will those changes cost? Who should pay for those changes?
The study even points toward the need for more studies;
The insights from the Hawaii Solar Integration Study form a large body of knowledge for future grid integration studies, and the results can be used to further our understanding of grid integration in other island systems as well as in mainland U.S. systems with high regional solar and wind penetrations.
The second article is about connecting three grids and little if anything about the impact of solar on the grid
The last article is a complaint and does not prove anything.
Here is the entire article;
Maui homeowners and photovoltaic system installers are expressing frustration at requirements that they pay for expensive "interconnection studies" before installing solar panels, with no guarantee that their project will be approved after the study is complete.
There is no reference to how much an interconnection study costs. Here is a better explanation about what an interconnection requirements study (IRS) is and what it is necessary in certain instances. An IRS looks into the local grid capacity to handle the input of electricity from the new installation and whether or not local upgrades would be required to accommodate it. Note that an IRS is only required when there is a lot of solar already on the local grid.
Note that the first two articles deal with much higher level grid issues and not local grids.
Look at the current policy from Hawaiian Electric. Notice that IRS's are only required if DML is >250%. They may be required at lower levels depending on the age and capability of the local grid.
I fail to see how any of this supports the statement that interconnect study requirement is unnecessary,
Sorry but posting a few links to article with the words "Hawaii", "grid" and "integration" is not research.
I do not believe there is a way to remotely disconnect an individual hose from the grid.
That is how the grid works now. What will happen of a large percentage no longer comes from dispatchable plants but instead from roof top PVs scattered all over the place?
Managing a grid is not complex at all.
Do you have any references that back up that statement?
How about you do some reading on grid complexity. Managing a grid is very akin to juggling many different inputs and outputs so the supply closely matches the demand. Our electricity system only works in a very narrow range of voltage and frequency. Go outside of those parameters and failures occur.
Over supply is handled by increasing the frequency and therefore the power capacity of the power line. Increase the frequency too much and electrical units can have problems. If a piece of equipment is expecting 60Hz and is getting 65Hz or 70Hz it may be damaged.
My point exactly. Managing the grid is very complex and adding a huge number of uncontrollable variable inputs does not make it any easier.
So you would have water on the other side of a mountain. What good would that do? Could't you just desalinate the water on that side of the mountain?
References please.
but we seem to be moving toward an era of self-generation as a primary source of power
Anyone who lived in a multi-story building will not be self generating. While self generation might be good for some sub-urban and rural areas there is no way it will suffice for urban areas. Therefore the grid will always be needed.
Your hot water analogy is way off considering that a day's worth of PV power may not even last part of a day. That would not be good if your refrigerator only worked part of the day or your computers used for work did the same.
Spoken by someone who truly does not understand how unstable an electric grid really is. If there is more power injected into the grid than there is demand very bad things happen.
True, but allergies require a substance to actually be a food .
Sorry but this is incorrect. Latex is not a food but some people are allergic to it.
(a substance that most people's body can process, but yours can't
Allergies have nothing to do with ability to process a substance. Allergies are an immune system overreaction to a substance.
In this case there is a specific disorder that causes problems in a small number of people; Phenylketonuria
I think it is funny that this comment come under the "Do the Math" heading.
10,000,000 x .02 = $200,000
That is not insignificant when talking about profit.
Unless it costs 3x as much to make.
So, yes, aspartame is extremely harmful for a small minority of people.
There are many substances that are extremely harmful to a small number of people either through allergies or sensitivities.
McDonalds claims their customers like the coffee at a higher temp (175-180) since they often commute and don't drink it for a while.
I guess you don't commute either. Most people who get coffee at a drive through start drinking it immediately.
From the article;
Other establishments sell coffee at substantially lower temperatures, and coffee served at home is generally 135 to 140 degrees.
Further, McDonalds' quality assurance manager testified that the company actively enforces a requirement that coffee be held in the pot at 185 degrees, plus or minus five degrees. He also testified that a burn hazard exists with any food substance served at 140 degrees or above, and that McDonalds coffee, at the temperature at which it was poured into styrofoam cups, was not fit for consumption because it would burn the mouth and throat. The quality assurance manager admitted that burns would occur, but testified that McDonalds had no intention of reducing the "holding temperature" of its coffee.
That is an admission of guilt and recklessness by McDonald's,
They finally changed their policy
Post-verdict investigation found that the temperature of coffee at the local Albuquerque McDonalds had dropped to 158 degrees fahrenheit.
Similarly, I also don't blame knives for being "too sharp" when I drop one on my foot ...
You miss the point that a sharp knife will not cause damage if used correctly. Coffee at 180 degrees would burn the mouth of consumed.
This might be one of the reasons that Tim Horton's actually puts in the cream and sugar so you don't have to on the car.
You are saying even if they felt like they didn't do anything wrong,
There is the rub. They knew they were doing something wrong and did it anyway. They knew they were brewing coffee too hot as they had been warned several times before. They brew hotter so more flavour is extracted and less ground coffee needs to be used. One of the reasons the award was so bit gas that they put a few dollars profit above customer safety. Serving coffe at a temperature that would burn the inside of the mouth when it is designed to be consumed immediately is what got them into trouble.
But on the other hand I (and most people) brew coffee at > 180 degrees at home every day and manage not to soak cotton sweatpants with it to cook our skin for 30 seconds.
I bet that you cool the coffee with milk, as she was trying to do, or wait until you drink it. Coffee that hot would burn your mouth.
Which I have to say, I don't pity them much for. But I also don't think the lawsuit made much sense.
Read a few more facts and you will see that justice was served.
If you imagine shooting an arrow at a wooden ball, unless you hit dead center, it’ll ricochet.
Being crushed between two icebergs is not a point force. A closer analogy would be a ping pong ball between two large blocks of wood. The ball gets crushed.
Each different country should be able to follow it's laws. It is up to the people in the country to change those laws if desired.
Therefore disseminating information about where you can download something is speech.
I agree that disseminating information is protected speech. I do not agree that disseminating the copy written property of someone else is protected speech.
The moment you start deciding that one thing is speech and another isn't, regardless of your personal views on the merits of that speech, you begin running headlong towards despotism.
Actually you begin running headlong toward a civil society. Hate speech, incite to riot, libel, slander, etc are not protected speech. These types of speech have been found to be detrimental to civil society and have been made illegal in most places. Just because something is auditory in nature does not make it protected speech.