0.4% design temperature for Perth is 36.2C. A DX system with condensers on the roof would be designed for a temporary stature of 41-43C typically. Once you get much above that, there isn't much you can do with DX; you will overload your compressors quickly. A cooling tower should be more robust, but your envelope load could have exceeded the primary system capacity.
Typically in extreme temperatures a Tier 3 data center will need to eat into its redundancy for cooling. Tier 4 facilities should be more robust, but you would not expect 2N redundancy when you have record temperatures.
As for load balancing and other edge conditions, it really depends on how heavily loaded a facility/portfolio is. What I expect happened was one part of their facility went down with a "hot spot" that didn't have adequate redundancy in the first place. It is an edge condition that likely required more capital than it was worth to resolve.
I generally love everything Apple does and makes. That said, they botched iOS 8 from a user perspective. Everyone I know who had a small flash went and deleted all their apps and data first so they could download the update. They needed to tell people that they could do a tethered upgrade and use less space for the upgrade.
The way they did it reinforces the "upgrades are bad" mentality which is dangerous. Apple can do better.
The only people we hire now have relevant experience and skills in our very specific field, and experience commensurate for the position we are posting. We have sadly given up on new graduates; they are too flakey, having never held an actual job before, and needing substantial training to get to a point where they can generate revenue... and leave. Now is a great time for people that graduated around 2010, found a job in their field at terrible pay, and are now ready for an actual career.
A jumper in the wrong place or an ice-cube relay being removed can ultimately have similar effects. Ban fingers too?
A properly designed system has one set of PLCs for primary control, and a separate one as a supervisory system to ensure basic functionality always is online. The secondary system wouldn't control pump speed, but it would ensure coolant is flowing of the system is on.
It would be relatively easy to keep a nuclear power plant from operating at peak efficiency, but unless IKEA or WalMart have started making reactors forcing more serious effects remotely is nearly impossible.
Only if you make the person leaving the message listen to a machine-reading of the transcribed message and then use T3 notation to edit the message win order to have it accepted will it ever work...
I am starting to contemplate requiring unknown callers to validate their name, company, and direct phone number...
Sorry, but I have to disagree. Our Asterisk system gives me caller, length of call, and time in an email immediately after. We had transcriptions enabled before, but they were terrible so I shut it off.
I appreciate that the telephone can be more efficient for a 2-way dialogue, but it's modality kills me. I can't change trains of thought on a dime and still get things done. To me, the courteous action is to send an email, and follow with a text if it is actually urgent.
Maybe if I got visual voicemail working for the office I could use it again, or if I could play the.wav or.gsm attachments on my iPhone i would feel differently, but right now it is a pain in the ass.
Hopefully they have some kind of one-time/vendor-specific account number rather than the actual account! Risk-based assessments are nothing new; hopefully knowing what the factors/algorithms are doesn't kill the effectiveness.
The fact that they are switching away from making energy consumption basis for charging you to peak demand. Expect peak demand fees to be assessed on generation as well before too long.
The major remaining challenge today for renewable energy is that peak demand has moved to an hour before sunset through two hours after sunset. There is talk about moving the peak period away from noon-time and to later in the day already. Local energy storage solves that remaining utility challenge quite effectively. After that, the utility just becomes a (bad) standby generator.
Right now, off-grid power with a nearby grid readily available is a poor investment, as are batteries when you are connected to the grid. It is cheaper to just add panels at $1.15/W than add batteries for net metering.
Cummins at least is dealing with particulate in the cylinder, and using after-treatment to deal with NOx. This eliminates the problem with PM2 generated by PM10 particulate filters. It is a pretty elegant solution and generally makes sense (although the DEF is a pain to need in addition to fuel.
It sounds more like a jobs program to disadvantage German cars though.
Depends on the environment. In Hawaii, underground lines have approximately half the life of aerial cables in general, and one third the life of aerial cables on steel poles. From a cost, reliability, and time-to-repair perspective you can't beat aerial there.
The biggest problem in general with the sub-distribution grid though is over-subscription. You have infrastructure designed pre-air conditioning that is now carrying 2-3x it's design load in many places. Transformers don't get replaced until they fail catastrophically, insulators aren't cleaned, and the right-of-way is not properly protected from trees, cars, etc.
If there isn't grounds for a trial, the grand jury isn't supposed to pass the buck. That is their job. It prevents an undue burden of defense.
The prosecutor is going to publish all data; it will be interesting to see what comes out. I think it is likely that the officer had a bias in the incident leading up to the shooting. However, that isn't something that can be prosecuted.
I find the claims of "hands up surrender" a little hard to believe personally, but that is my bias based on the fact that he was high, possibly had a knife, was quite large, and had just stolen something. The "surrender" pose seems suspicious. The evidence will be interesting to peruse.
Yes, the government fsck'd up the helium market, but for applications like this it isn't that big of a deal. You can use hydrogen instead, although the flight time will likely be half due to leaks. For a while there was a good bit of research into using hydrogen as a deep diving gas in place of helium, but pesky safety issues got in the way.
Los Angeles has made significant progress over the past two decades with mass transit; they have 87 miles of track, and the system is expanding. Unfortunately, geography doesn't help them as much as it does for the SF Bay Area (BART has 104 miles of track).
Los Angeles is a failure of metropolitan planning, especially in the late 70‘s through the 80‘s where several outlying cities popped up. This isn't sustainable, and the solutions you outline are important to making things work well. Unfortunately, it isn't that uncommon to need to drive 50 miles in a day each way given economic realities. As the manufacturing base declines it will be interesting to see what happens to the area. Me, I live close enough to work that I can ride my bike in and not own a car. Not realistic for most people though.
I used to think the same thing, until I ran the numbers. The simplification in system architecture alone justifies the change, and once you throw in NFPA 70E distributed backup of a local dc bus quickly makes more sense.
It doesn't work for all applications, and you need the IT staff (rather than facilities staff) to make it work, but it can simplify things tremendously.
LiIon is great when you just want 30-60 seconds backup, and is economical there. Knowing Facebook, they likely load balance to charge the racks on off-peak energy and discharge during peak period, even if it is just a minute x15kW per rack for the trivial savings.
"Pure lead" batteries are likely more cost effective, but they are larger and heavier.
Biodiesel has a very short shelf life-- 3 months max. You need to use it if you make it. The best strategy I have seen is basically having segregated tanks, with the one at 2-2.5 months being used for fleet vehicles. Aside from this being illegal in the US, it is a lot of fuel to need for the fleet of a hospital. An average hospital in California has 30-40,000 gallons of diesel; 10,000 gallons per month is a lot to use in other ways.
That said, the answer is energy storage in whatever forms are viable. The "Cold Winter Night" scenario is fully manageable between candles and fires residentially and diesel generators commercially, assuming you still have or can import 10-20% of your peak demand. The real problem is an arctic front that lingers for a week with far below normal temperatures.
As long as there is no reference to the password being emailed separately, it is fairly reasonable basic level of security. If someone cares, the zip password protection is weak enough that it won't keep a secret long from the boogeyman.
$20MM per year in rent for an airfield, golf course, and of course the hangars! Google got a steal; they likely paid more for parking rights for their planes.
You might be underestimating the cost benefit ratio for wireline service. Incremental cost to provide service to a customer in the coverage area with fiber ranges from $700-10,000. For satellite you are looking at $300-500 worst-case, anywhere in the world (you are able to provide service).
The advantage of wireline (especially fiber) is you can realistically recapture your investment over 20-50 years. Satellite is more like 5-10 years.
No, Irridium's failure was in that they had an extremely low bandwidth design initially, when other higher bandwidth options were becoming available for the majority of applications, at substantially lower costs. Adding to the challenge is the fact that upgrades are harder.
A new generation can be planned out as needing to eventually compete with gigabit networks. $700MM For a constellation (plus launch and ground facilities of course) might make it possible to refine the design and do faster upgrades if warranted.
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0.4% design temperature for Perth is 36.2C. A DX system with condensers on the roof would be designed for a temporary stature of 41-43C typically. Once you get much above that, there isn't much you can do with DX; you will overload your compressors quickly. A cooling tower should be more robust, but your envelope load could have exceeded the primary system capacity.
Typically in extreme temperatures a Tier 3 data center will need to eat into its redundancy for cooling. Tier 4 facilities should be more robust, but you would not expect 2N redundancy when you have record temperatures.
As for load balancing and other edge conditions, it really depends on how heavily loaded a facility/portfolio is. What I expect happened was one part of their facility went down with a "hot spot" that didn't have adequate redundancy in the first place. It is an edge condition that likely required more capital than it was worth to resolve.
I generally love everything Apple does and makes. That said, they botched iOS 8 from a user perspective. Everyone I know who had a small flash went and deleted all their apps and data first so they could download the update. They needed to tell people that they could do a tethered upgrade and use less space for the upgrade.
The way they did it reinforces the "upgrades are bad" mentality which is dangerous. Apple can do better.
The only people we hire now have relevant experience and skills in our very specific field, and experience commensurate for the position we are posting. We have sadly given up on new graduates; they are too flakey, having never held an actual job before, and needing substantial training to get to a point where they can generate revenue... and leave. Now is a great time for people that graduated around 2010, found a job in their field at terrible pay, and are now ready for an actual career.
A jumper in the wrong place or an ice-cube relay being removed can ultimately have similar effects. Ban fingers too?
A properly designed system has one set of PLCs for primary control, and a separate one as a supervisory system to ensure basic functionality always is online. The secondary system wouldn't control pump speed, but it would ensure coolant is flowing of the system is on.
It would be relatively easy to keep a nuclear power plant from operating at peak efficiency, but unless IKEA or WalMart have started making reactors forcing more serious effects remotely is nearly impossible.
Only if you make the person leaving the message listen to a machine-reading of the transcribed message and then use T3 notation to edit the message win order to have it accepted will it ever work...
I am starting to contemplate requiring unknown callers to validate their name, company, and direct phone number...
Sorry, but I have to disagree. Our Asterisk system gives me caller, length of call, and time in an email immediately after. We had transcriptions enabled before, but they were terrible so I shut it off.
I appreciate that the telephone can be more efficient for a 2-way dialogue, but it's modality kills me. I can't change trains of thought on a dime and still get things done. To me, the courteous action is to send an email, and follow with a text if it is actually urgent.
Maybe if I got visual voicemail working for the office I could use it again, or if I could play the .wav or .gsm attachments on my iPhone i would feel differently, but right now it is a pain in the ass.
Hopefully they have some kind of one-time/vendor-specific account number rather than the actual account! Risk-based assessments are nothing new; hopefully knowing what the factors/algorithms are doesn't kill the effectiveness.
Check out how much insurance is for a limo driver. That kills Uber in a second.
The fact that they are switching away from making energy consumption basis for charging you to peak demand. Expect peak demand fees to be assessed on generation as well before too long.
The major remaining challenge today for renewable energy is that peak demand has moved to an hour before sunset through two hours after sunset. There is talk about moving the peak period away from noon-time and to later in the day already. Local energy storage solves that remaining utility challenge quite effectively. After that, the utility just becomes a (bad) standby generator.
Right now, off-grid power with a nearby grid readily available is a poor investment, as are batteries when you are connected to the grid. It is cheaper to just add panels at $1.15/W than add batteries for net metering.
Economics. Drivers don't go out when they can't make any money. Painful way to limit capacity, but it will happen eventually.
Cummins at least is dealing with particulate in the cylinder, and using after-treatment to deal with NOx. This eliminates the problem with PM2 generated by PM10 particulate filters. It is a pretty elegant solution and generally makes sense (although the DEF is a pain to need in addition to fuel.
It sounds more like a jobs program to disadvantage German cars though.
Belgium might not be the best example. Do they have a government yet?
Depends on the environment. In Hawaii, underground lines have approximately half the life of aerial cables in general, and one third the life of aerial cables on steel poles. From a cost, reliability, and time-to-repair perspective you can't beat aerial there.
The biggest problem in general with the sub-distribution grid though is over-subscription. You have infrastructure designed pre-air conditioning that is now carrying 2-3x it's design load in many places. Transformers don't get replaced until they fail catastrophically, insulators aren't cleaned, and the right-of-way is not properly protected from trees, cars, etc.
A lot of the buildings in the area date back to the 1950's, so limited sprinklers is reasonable.
If there isn't grounds for a trial, the grand jury isn't supposed to pass the buck. That is their job. It prevents an undue burden of defense.
The prosecutor is going to publish all data; it will be interesting to see what comes out. I think it is likely that the officer had a bias in the incident leading up to the shooting. However, that isn't something that can be prosecuted.
I find the claims of "hands up surrender" a little hard to believe personally, but that is my bias based on the fact that he was high, possibly had a knife, was quite large, and had just stolen something. The "surrender" pose seems suspicious. The evidence will be interesting to peruse.
Yes, the government fsck'd up the helium market, but for applications like this it isn't that big of a deal. You can use hydrogen instead, although the flight time will likely be half due to leaks. For a while there was a good bit of research into using hydrogen as a deep diving gas in place of helium, but pesky safety issues got in the way.
Los Angeles has made significant progress over the past two decades with mass transit; they have 87 miles of track, and the system is expanding. Unfortunately, geography doesn't help them as much as it does for the SF Bay Area (BART has 104 miles of track).
Los Angeles is a failure of metropolitan planning, especially in the late 70‘s through the 80‘s where several outlying cities popped up. This isn't sustainable, and the solutions you outline are important to making things work well. Unfortunately, it isn't that uncommon to need to drive 50 miles in a day each way given economic realities. As the manufacturing base declines it will be interesting to see what happens to the area. Me, I live close enough to work that I can ride my bike in and not own a car. Not realistic for most people though.
Yes, it lasts forever. Just don't try to run it through an engine after 3 months. If you are lucky it just clogs the filters.
Regular diesel is good for 6-12 months before a polishing is needed. Polishing completely at 3-4x the frequency has its own problems.
I used to think the same thing, until I ran the numbers. The simplification in system architecture alone justifies the change, and once you throw in NFPA 70E distributed backup of a local dc bus quickly makes more sense.
It doesn't work for all applications, and you need the IT staff (rather than facilities staff) to make it work, but it can simplify things tremendously.
LiIon is great when you just want 30-60 seconds backup, and is economical there. Knowing Facebook, they likely load balance to charge the racks on off-peak energy and discharge during peak period, even if it is just a minute x15kW per rack for the trivial savings.
"Pure lead" batteries are likely more cost effective, but they are larger and heavier.
Biodiesel has a very short shelf life-- 3 months max. You need to use it if you make it. The best strategy I have seen is basically having segregated tanks, with the one at 2-2.5 months being used for fleet vehicles. Aside from this being illegal in the US, it is a lot of fuel to need for the fleet of a hospital. An average hospital in California has 30-40,000 gallons of diesel; 10,000 gallons per month is a lot to use in other ways.
That said, the answer is energy storage in whatever forms are viable. The "Cold Winter Night" scenario is fully manageable between candles and fires residentially and diesel generators commercially, assuming you still have or can import 10-20% of your peak demand. The real problem is an arctic front that lingers for a week with far below normal temperatures.
As long as there is no reference to the password being emailed separately, it is fairly reasonable basic level of security. If someone cares, the zip password protection is weak enough that it won't keep a secret long from the boogeyman.
$20MM per year in rent for an airfield, golf course, and of course the hangars! Google got a steal; they likely paid more for parking rights for their planes.
You might be underestimating the cost benefit ratio for wireline service. Incremental cost to provide service to a customer in the coverage area with fiber ranges from $700-10,000. For satellite you are looking at $300-500 worst-case, anywhere in the world (you are able to provide service).
The advantage of wireline (especially fiber) is you can realistically recapture your investment over 20-50 years. Satellite is more like 5-10 years.
No, Irridium's failure was in that they had an extremely low bandwidth design initially, when other higher bandwidth options were becoming available for the majority of applications, at substantially lower costs. Adding to the challenge is the fact that upgrades are harder.
A new generation can be planned out as needing to eventually compete with gigabit networks. $700MM For a constellation (plus launch and ground facilities of course) might make it possible to refine the design and do faster upgrades if warranted.