Posted by Will on December 29, 2007, 10:40 pm
Does anyone make power meters that allow the usage data to be collected
centrally and graphed over time? I am NOT looking for panel meters. I
want meters that either replace a wall receptacle or will act as a PDU
plugging into a wall socket. The application is power metering across each
device within a building, in order to determine which devices are eating up
the most energy.
There are many consumer level power meters that show a readout on an LCD
attached to the meter. That's not my application. It doesn't capture the
historical usage that is so important to my overall goal, and it doesn't
facilitate a higher level aggregation of the data. And who has time to
walk around all day doing spot readings?
There are many PDUs that have built in web pages that show power data, but I
have not found any (yet) that allow the data to be collected centrally and
then graphed historically, by device, or collectively. Again, who has the
time to connect to 20 web pages to get a collective view of power
utilization for the home or business?
The meters would obviously need TCP/IP connectivity (either RJ-45 or
wireless) and some software that could be run centrally to download the spot
data from each meter and then store those readings in a database.
I am not looking for a home engineering project with meter clamps, thanks.
I need to be at or under $00/meter, a bit more than that if the device is a
There appears to be a real lack of imagination among products in this area.
There are dozens of products chasing the high end of the market, selling
high end panel meters to utility companies. There is a complete wasteland
and dearth of products selling to the low end of the market. I'm excluding
the spot monitoring devices like "Kill-a-Watt" because they are way too
simplistic to deal with understanding overall energy utilization over weeks
of time. Yet there are plenty of consumers with $00 utility bills, and
plenty of businesses with $K utility bills, who could be saving $K or more
per year off those bills if they had data on which to make intelligent
energy management decisions. Doing that however might require monitoring
20 outlets in a home or business. No one gets return on investment
spending $K per outlet for a high end power meter because they have to
invest $0K to save $K annually. It's a bad investment.
It is a travesty that with all of the competitive businesses that are
technically able to deliver these kinds of products, that few or no
companies have seen the market opportunity for the kinds of meters I am
describing. Has anyone found anything even close?
Posted by Arnold Walker on December 30, 2007, 7:27 am
Sounds like you are describing a watts up pro es
A little over the 200dollars you mentioned, but the big brother to a Kill a
It has a computer plug in ,so that your laptop/ desktop can do anyalsis
work from the readings.
(using software on the cd for the computer)
Far cheaper than industial power management systems from Bradley,etc.
Posted by Will on December 30, 2007, 10:29 am
So how do I consolidate 20 Watts Up Pro ES units to a single management
station? I have to come up with a serial to TCP/IP conversion for 20
different monitors, and then somehow deal with the software manually
reconnecting to 20 units to gather the data?
Sounds like a part time job to keep up with all of that work....
Posted by Will on December 30, 2007, 7:11 pm
Looks like Watts Up is about to release a ".NET" version that lets you
upload data by TCP to their public web site. That looks more promising
and I'll have a look.
Posted by spaco on December 30, 2007, 8:32 pm
Try www.dataq.com. I see input devices ("amplifiers" or
"conditioners") for about $9 each that can sense what you say you want.
That leaves you 2 grand for the DAU plus software. I see DAU's with at
least 16 inputs. Should work out okay with your $00 per receptacle
budget. If you have some electronics expertise, you should be able to
do the "conditioning" stuff yourself.
If all the receptacles are 120 volts, then all you REALLY need is to
measure current. Even if some are 220, you already know that THAT'S
always going to be 220, so you still need only measure current, letting
you analysis software multiply the appropriate voltage. If you are
really fussy because of some highly inductive loads, you need to measure
KVARS, etc. and you are on your own.