I was wondering about the various devices like "current cost",
"kilawatt", and "owl" that measure your electricity usage. I know they
have been discussed on here before and some people have said why do
you need one of these when you already have an electricity meter, and
there is some logic in that.
My electricity direct debit has jumped from 60-odd pounds per month to
ninety-odd pounds. I think that's due to changes in prices rather than
changes in usage, however I would like to see what I am using to see
if there is anywhere I can tweak some savings. I think using one of
these meters might be quicker and easier rather than read the "proper"
meter every night or do mental arithmetic based on how many flashes of
the LED or rotations of the disc (depending on your meter) there are.
Are these makes all much the same or are some models better than
others? It would be nice to be able to view the data on the computer
and it would be even nicer if the device logged usage so that I did
not have to leave the computer on to download from the device in real
time: that would only add to my usage!
I think that these meters give a faster response, i.e. you can run
around the house switching sockets off individually and seeing the
drop there and then, rather than switching off one socket per day and
measuring the difference each morning.
You can also see how much difference switching lights off in
unoccupied rooms makes.
That's good for finding out how much energy the various dishwasher &
washing machine programmes use, & for learning that most of our wall
warts use no measurable power when plugged in but not charging.
I bought a "loop" from the Ideal home exhibition last week (£20)
You get two devices, one that you clamp around your meter tail (this has
an integral long life battery), the other you connect to your broadband
router (this one needs a power supply, which can be taken from the
router if it has a USB port, or via the included mains adaptor)
This then shows you (via a web page) your real-time usage, and all
historic usage - once they have 30 days of usage, they will then be able
to recommend different suppliers based on your actual usage.
they claim to have a gas transmitter that will be available later this
year, someone reading the dial on the meter, apparently the receiver
unit has 16 channels, so hopefully it will be able to read other things
like water meters and exported power if you have solar etc..
The parent company is http://www.navetas.com/ which appears to be a well
There is also a subscription to pay and unlike other monitors, it does
not help you identify things that are take more power than you think.
Once you stop paying the subscription, the thing is a bit of a chocolate
It has a real-time meter you can access on a computer, or a smart phone
(there also an Android app, and an iPhone one is in progress), so it
shows the same as any other clamp meter based one will.
It reacts in a few seconds to a load change, pretty much like my Owl
meter does, maybe a second longer.
It comes with 12 months, and then it is £5 for the next year, so 42p a
month for them to provide the data storage, graphs, enabling me to check
I haven't left anything on when I am not at home, and switching
recommendation, I don't think that is a bad deal personally.
On Thursday, March 28, 2013 6:16:45 PM UTC, Toby wrote:
I'm not sure there is a need for such a charge..
data storage, just what sort of space is required hardley GB
more like kb . Graphs ???.
But I guess if you're happy with such a charge, letds just hope it doesn't
increase too much. I assume like leccy and gas it'll go up in cost adn stor
age costs come down and such things reduce in cost the price will rise :-)
eon run an energy monitor website free for customers.
If you don't have smart meters you have to upload the data yourself.
They also give away free current cost monitors and the PC software to
monitor them. (or they did last time I got one)
I suppose it depends how determined you are to log it manually. My
electricity meter requires considerable effort, a torch and a step
ladder to read. The Owl by comparison sits on a windowsill and gives
(nearly) immediate feedback. Expect to shave about 10% off your bill by
having one even if you are relatively good about switching lights off.
I found a couple of orphaned wall warts drawing 20W continuously behind
furniture when I got mine. Getting your overnight base load down is the
first easy thing to do - many modern TVs default to running the digital
decoder in case your DVD recorder might want to use it.
10W continuous load is 80kWh or approx £10 off the annual bill.
It is also worth having a more sensitive plug/socket based device that
can measure standby power down to fractions of a watt. That way you can
decide if any of the kit you have needs isolating from mains when not in
use. Various smart extension sockets and adaptors exist for this.
That is a very big change - what new toys have you bought?
Plasma TV is the most obvious suspect.
Unless you really want to play at logging then the Owl is good enough -
you might even persuade your electricity supplier to give you one...
The saving for our village hall is massive because it stops people
leaving the electric heating, ovens or hot water immersion on overnight.
The OWL will heavily over-estimate the load of those.
They won't have been anything like 10W each, but possibly 10VA.
The OWL doesn't have enough data to make an accurate measurement
like your meter does.
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Virtually all these cheap ones suffer from this. They do not have the
capability to use a voltage/phase sample and so assume unity power
factor and additionally if you have solar panels or such like, the
output from these is registered as CONSUMPTION which unless you
understand what is going on, will be very confusing.
Owl told me a year or so ago they were working on something more
sensible but I've yet to see it available.
Granted that the phase angle meant it was probably not dissipating
anything like 10W but it was enough that the transformers were warm to
the touch despite being unloaded. Finding and removing them must save
some power even if it was only half what the Owl thought.
The devices that plug into a mains socket and accept a 13A plug should
be able to do proper phase correction for consumption - although whether
the one I have does or not I have never bothered to check.
Basically it is worth it to find and eliminate wasteful appliances.
On Thu, 28 Mar 2013 16:05:54 +0000 (UTC), Andrew Gabriel wrote:
I had a free meter with a clamp and WiFi to the monitor - it was so bad that
I gave it away to an electrician!
The plug-in meter from Maplin at least shows, e.g., a 20W CFL as 20W and
about 38VA; it also shows the PF-corrected 30W CFL as 30W and 31VA.
Most of what I want to know runs from 13A plugs and so I can measure it
(even the PC on, of course SMPSU, seems to be quite accurate at 45W as the
330W PSU never gets warm). I haven't bothered to measure the Humax FS PVR as
it has to be on when required anyway - if I get a tuit...
The items that don't plug in are resistive mainly, except for the boiler.
Overall I know pretty well what the power and energy are and an accurate
clamp-on meter would be interesting but academic.
I have one of those (on loan from the local library) & noted that
neither of the components (the clamp-on ammeter & transmitter; the
receiver & display) plugs in --- they both run on batteries --- so
there's no way for it to measure the phase difference or power
I have a socket within 1 metre of the meter, so I could use something
with a plug-in ammeter-transmitter, but is that an unusual layout?
In a domestic situation, the OWL will never under-read, since domestic
customers are charged for kWh rather than kVAh --- is that correct?
For most practical purposes, probably yes. It would underread if
your mains voltage was higher than it was set to or guessing.
I don't know how accurate it is at handling a heavily non-sinusoidal
current waveform - for example, if it derives something other than
the RMS value, then it's not even giving you the VA rating, and you
might be getting something either higher or lower than the real
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