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Use Linux to Reduce Your Power Bill
Stephen Herzog writes "Linux Devices has published an article about the AcquiSuite, a Linux based hardware device that collects and reports energy consumption information. Companies who are looking at energy management solutions need to keep the cost down in order to recover their retrofit cost with savings from the energy bill. Linux is a perfect fit for cheap data collection devices in part because "Linux provides complete TCP/IP functionality, PPP... and no royalties"."
We call the power company, and they give us detailed reports on how much power each site is using, and day-by-day breakdowns, comparisons with last year...
Your father doesn't know what he's talking about. Power quality is a MAJOR issue. Any place with large amounts of inductive loads (ie fluorescent lights, motors, etc) can easily triple their electrical bill by not having a good power factor. It is standard practice for electrical companies to charge extra if your power factor is bad as well. What he may be referring to is heaters. A heater is not an inductive load, so it will already have a power factor close to unity. However, in a large building with lots of motors/fans/air conditioning, power factor is a very important consideration. And if you get into an industrial setting, you would have to be completely insane not to care about power quality.
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All of whose base are belong to the what-now?
I've already worked with two companies doing almost exactly the same thing.Check these out:
www.enflex.net/products/mg-200.htmlwww.envenergy.com/products/medhardware.shtml
Both are embedded linux systems for building automation, power consumtion monitoring, and providing information about the monitored systems over the internet.
"Prefiero morir de pie que vivir siempre arrodillado!"
With respect to persons saying that energy savings is not practical.
We typically sell the AcquiSuite product to contractors who work on a performance based contract. The building owner pays some fixed amount for a retrofit which includes things like CF lamps, new motors, etc. The contractor only gets paid when the proposed reduction in electricity is verified. Typical contracts suggest 7-8% reductions in buildings with $20k anual electric bills. The AcquiSuite is used in these projects as a measure of before and after, and is used for ongoing maintainance.
Windows 9x doesn't. NT/2K/XP do.
You can get apps for 9x, such as Rain, that will run as a lowest-priority thread and issue the HLT commands.
Vintage computer games and RPG books available. Email me if you're interested.
Radio Shack has one here
"Prefiero morir de pie que vivir siempre arrodillado!"
For CMOS devices, the power consumed is proportional the TOGGLING of GATE STATES NOT the length of time that the device is energized.
From a processor viewpoint, just saying the Linux consumes more power because the machine in on more misses an important effeciency of Linux.
For friend of mine measured the CPU temperature for both Linux and Windows on the same machine.
Linux ran at about 78F degrees. Windows ran at about 92F degrees. Same tasks for both.
Hotter chip means more energy consumed and shorter chip life.
Linux should get credit for measurebly more effecient use of cpu gates.
--Hopscotch
I work for a building automation systems manufacturer and have designed, built, and sold energy management/building automation systems since 1987. Your father is operating from the perspective of an HVAC mechanic and has a particularly narrow perspective on energy management in general. Yes, replacing inefficient equipment can reduce costs at apparently minimal levels. However, he likely has never worked with a BAS that was configured correctly and adequately supported by the vendor.
A properly installed and configured building automation solution will find most of the savings are in finding ways to reduce demand through scheduling, staging, load sharing, load shedding, cycling, super-cooling, and other strategies. By reducing demand, you can go to a utility and negotiate reduced rates based on staying withing certain demand levels during peak times during the day.
Simple things like making sure the lights, HVAC, and things like escalators come on at the right time in a staged order (to prevent demand spikes), and only where they are needed and are shut off when they are not in use (at night) can save a large facility literally millions every year.
Changing out HVAC equipment for more efficient equipment is a very tiny part of the puzzle.
BTW- all of the major BAS manufacturers (including my employer) have such a meter-monitoring unit, and many of them or related systems are increasingly based on embedded Linux. Meter monitoring units are useful to monitor a facility before it is put under complete control to determine where the savings can be found. Once the facility is in place, meter monitoring and associated daily reports are typically used to ensure that the system is operating properly, but in this case there is much more information available.
So to say you might only get a $200 to $500 payoff over 15 years is small potatoes compared to the potential millions you can save at a typical big-box retail, manufacturing facility, or large high school.
GTWreck
I know Steve and the guys behind the AcquiSuite. I designed the Veris Enercept power meter that's shown on their home page. In fact, I can probably take credit for convincing them to go with Linux on x86 a few years ago (they were also seriously considering PSOS on the netsilicon ARM+ethernet hardware). I didn't actually participate in the AcquiSuite though, and I'm not affiliated with them, and I recently left Veris Industries. So take the rest of this comment with a grain of salt... I'm not totally impartial, but I do know quite a bit about the system.
The AcquiSuite is designed for use in commercial buildings and groups of buildings. It can monitor many power lines, not just one socket. The Veris Enercept meters are typically installed in the breaker boxes that feed major sections or subsystems of a building. These meters are meant for 3-phase power systems in the 20 to 2400 amp range, not single-phase 120 volt, 15 amp residential. The AcquiSuite also interfaces to temperature, humidity and other types of sensors.
There's three major factors (as I understand):
One of the key factors is cost... since this thing is supposed to save energy, it needs to be a lot less expensive that what it costs to install.
Compare to the "Kill A Watt" (which actually offers similar functionality for single-phase 120 volt as the Veris Enercept, but on a LCD instead of RS-485 network). With a simple meter like that, you can look over at it and see the power company is give the correct voltage, and how much current/power you're using at any particular time. You can see the accumulated consumption, so you could jot that number down every month and see how much the attached load cost you.
But to be useful in truely saving money, you need to log the data, collect that data, and get an analysis of that data in a timely manner.
You can go to your conventional power meter, be it the "Kill A Watt", Veris Enercpt, or the "glass meter" on the side of your house and read what it says. If you remember what it was last time to read it, say a week ago, you might say "damn, I used a lot of power this week, I'll have to try to do better next week... but how?"
Now enter the AcquiSuite (or other data logging methods): when you're wondering about your power usage, you visit a website using your browser, and in seconds you have a detailed plot showing how much power you were using throughout the day. It's similar to those bandwitch graphs from MRTG, you see a massive anamoly and say "holy sh*t, what happened the night before last that used so much power"? Or perhaps you see the longer time scale and see that something hogs lots of power every Monday morning. Or perahsp you compare graphs for similar office spaces in different buildings and see that one office uses a lot more power than the others, and perhaps only in the morning.
This is the sort of information that you really need to find where power is being wasted. And it's the timely fashion that's required to actually do something about it. You can find the janitor who didn't turn the light off, or modify a factory start-up proceedure for sequencing those machines properly on Monday morning, or fix the heating system in that one office that's using too much power.
That is what the AcquiSuite, and systems like it, are all about. They log data on a fine enough time scale from enough locations that you can (hopefully) see those unexpected events that are wasting power and costing money, and you can see them very shortly after they occur, so you can actually go do something about them.
One of the neat things about the AcquiSuite is it's ability to use the internet (linux tcp/ip stack and ppp). It can call an ISP and upload its data to a server, and as I recall it can be set to do this on a schedule with many others, so that a whole bunch of them can share just one dial-up account to send their data. I was told that a lot of people install them on their existing fax line, since it only makes calls infreqeuently and off of business hours. There were a bunch of other simple but nice features to the AcquiSuite that Steve was telling me about, but they escape me right now. Oh well.
I hope this has cleared up some of what this is all about. I know a lot of slashdotters see a product and only think of its application in a resedential application, mainly their house, appartment, dorm room, etc. This thing is targeted at commercial builds and groups of buildings.
PJRC: Electronic Projects, 8051 Microcontroller Tools
This was done along time ago by a company called Enertec. Real cool tech that runs and monitors the building with 3D models, etc.
Ummm, electrical devices with a poor power factor do NOT consume more power, ie they wont
increase your power bill. What they will do is increase the line current to the device.
But since this increased line current is out of phase with the voltage on the line no additional real power is used.
Industry and electrical suppliers tend to be concerned with power factor because increased line current means you need larger conductors to supply the load which means higher cabling costs.
Trust me, I'm an electrician
I had noflushd installed on my laptop for a while. It not only spins the drives down (well, it tells hdparm to tell the drives...), it caches all filesystem writes. So, if your problem is things writing to the disk, noflushd will be of use to you.
I stopped using it because I put XFS on the disk. Journaling filesystems tend to bypass some of the kernel disk-writing procedures in order to make sure the journal is correct. If you're using a journaling filesystem, that may be the cause of your problems. I'm not sure there's any way around this, because the filesystem seemed to write things about every five or so minutes regardless of whether I was actually reading or writing to the disk.
--Phil (And now the laptop itself is dead. Sigh.)
355/113 -- Not the famous irrational number PI, but an incredible simulation!