I'd like to play with one of the various energy monitoring gadgets that seem to be everywhere these days. I'm looking for one that will transfer data to my PC, and obviously that PC is running Linux (Ubuntu 11.04 at the moment, not sure if it will go to 11.10 yet...)
Any suggestions/recommendations?
I'm as lazy as they come so ideally I'm looking for something that can be permanently connected to my PC (therefore presumably a wireless connection will be involved at some point); I don't really want a box that collects data that I then take to my PC to download it once a week/month/year/never. And I'm also looking for access to the raw data, but also suggestions for suitable GUIs welcome too.
Mark
On 14/11/11 11:23, Mark Rogers wrote:
Any suggestions/recommendations?
Not used one with a PC interface myself and my Efergy broke (2nd unit in the warranty period and that one failed when the warranty expired, don't buy an efergy as even in the short periods where it was working it munched batteries)
But when I looked around for a replacement the currentcost units seem to have the most Linux options. I think however the data lead you require is a separate purchase or at least used to be on the original units. Still not actually gotten around to buying one so let me know how you get on with whatever you decide.
I got into a familiar theme with this sort of thing of being frustrated at what was available..deciding I could do better at rolling my own and then losing interest/not having time :)
On 14/11/11 16:42, Wayne Stallwood wrote:
But when I looked around for a replacement the currentcost units seem to have the most Linux options. I think however the data lead you require is a separate purchase or at least used to be on the original units. Still not actually gotten around to buying one so let me know how you get on with whatever you decide.
Just to let you know that from my research, the original CurrentCost offering, the Envi, does require a separate cable, but the newer model (EnviR) comes with said cable. I think the combined cost of Envi+cable is more or less the same as the EnviR and I can't find any other differences but I found someone with a spare EnviR on eBay and decided to stop researching and just get it!
I was quite tempted by the EnviR with OptiSmart (eBay 180742496157), with the latter being a sensor to monitor the pulses from the actual incoming meter (subject to suitable meter) and transmit that to the Envir wirelessly, but decided I could go and read the meter every so often instead. At some point I'll probably add some appliance monitors too but there comes a point when the cost of monitoring everything massively outweighs any savings from analysing the data...
On 15/11/11 09:24, Mark Rogers wrote:
I was quite tempted by the EnviR with OptiSmart (eBay 180742496157), with the latter being a sensor to monitor the pulses from the actual incoming meter (subject to suitable meter) and transmit that to the Envir wirelessly, but decided I could go and read the meter every so often instead.
Actually the point of reading the pulses from the meter is that the meter is pretty damn close to being 100% accurate in real terms and is 100% accurate in terms of what you are paying for.
On 15/11/11 23:32, Wayne Stallwood wrote:
Actually the point of reading the pulses from the meter is that the meter is pretty damn close to being 100% accurate in real terms and is 100% accurate in terms of what you are paying for.
Absolutely, but I can still verify the data coming from the CT [*] by manually checking the meter periodically. If there's a big discrepancy I can adjust for it (and possibly buy the OptiSmart if I need to), although if the CT measurements aren't accurate then any hope of sub-metering with extra devices around the house goes out of the window. (Also, for this reason I wouldn't want to just have pulse counting at the main meter and use the CT to sub-meter (eg) my server, because if the CT would give inaccurate reading at the main meter then it'll still be giving inaccurate readings at my server but I won't know about it.)
What I do like, is that by offering a device to read meter pulses it suggests that the manufacturer is fairly confident about the accuracy of their other kit.
[*] CT = Current Transformer = the bit you clip over your mains cable to measure the current, http://en.wikipedia.org/wiki/Current_transformer
On 17/11/11 09:21, Mark Rogers wrote:
On 15/11/11 23:32, Wayne Stallwood wrote:
Actually the point of reading the pulses from the meter is that the meter is pretty damn close to being 100% accurate in real terms and is 100% accurate in terms of what you are paying for.
Absolutely, but I can still verify the data coming from the CT [*] by manually checking the meter periodically. If there's a big discrepancy I can adjust for it (and possibly buy the OptiSmart if I need to), although if the CT measurements aren't accurate then any hope of sub-metering with extra devices around the house goes out of the window. (Also, for this reason I wouldn't want to just have pulse counting at the main meter and use the CT to sub-meter (eg) my server, because if the CT would give inaccurate reading at the main meter then it'll still be giving inaccurate readings at my server but I won't know about it.)
To be honest the supplied CT in the kit isn't really suitable for measuring the consumption for a single device or a group of devices anyway, you need the IAM's for that.
The current transformer needs to be attached to a cable carrying a single pole (Live) of a single phase...If you attach it to say a mains flex feeding a 4 way extension bar then the two poles (Live and Neutral) of a single phase in the flex have opposing fields and therefore cancel each other out.
On Thu, Nov 17, 2011 at 09:12:54PM +0000, Wayne Stallwood wrote:
On 17/11/11 09:21, Mark Rogers wrote:
On 15/11/11 23:32, Wayne Stallwood wrote:
Actually the point of reading the pulses from the meter is that the meter is pretty damn close to being 100% accurate in real terms and is 100% accurate in terms of what you are paying for.
Absolutely, but I can still verify the data coming from the CT [*] by manually checking the meter periodically. If there's a big discrepancy I can adjust for it (and possibly buy the OptiSmart if I need to), although if the CT measurements aren't accurate then any hope of sub-metering with extra devices around the house goes out of the window. (Also, for this reason I wouldn't want to just have pulse counting at the main meter and use the CT to sub-meter (eg) my server, because if the CT would give inaccurate reading at the main meter then it'll still be giving inaccurate readings at my server but I won't know about it.)
To be honest the supplied CT in the kit isn't really suitable for measuring the consumption for a single device or a group of devices anyway, you need the IAM's for that.
The current transformer needs to be attached to a cable carrying a single pole (Live) of a single phase...If you attach it to say a mains flex feeding a 4 way extension bar then the two poles (Live and Neutral) of a single phase in the flex have opposing fields and therefore cancel each other out.
I've never really understood the utility of any of the devices being promoted by the electricity companies which all (as far as I understand them) indicate your total electricity consumption. That's next to useless as it gives you no real clue as to what is actually eating your electricity.
In fact unless one can monitor in considerable detail (e.g. have a monitor on each circuit of the consumer unit, or even smaller areas than that) I can see very little point at all.
I do have a plug in device for measuring the consumption of whatever is plugged in to a single socket and that can be (somewhat) useful for checking how much something like a PC is consuming though of course the accuracy can be poor with switching supplies etc.
I've yet to see anything which indicates how much electricity the lights (for example) are using. At least not something available cheaply and to the general public, obviously it can be done if one uses a multimeter with AC ranges, but that's hardly what one wants.
On 17 November 2011 21:31, Chris Green cl@isbd.net wrote:
I've never really understood the utility of any of the devices being promoted by the electricity companies which all (as far as I understand them) indicate your total electricity consumption. That's next to useless as it gives you no real clue as to what is actually eating your electricity.
The key thing you get is usage against time. If I come home, put the oven on, eat, put the dishwasher on then settle in front of the telly, then look at the energy trend over that period, I'll get a pretty good idea of the relative usage of those appliances, and the background usage that runs throughout the night can be narrowed down pretty easily too. Of-course you'd want some appliance meters to confirm suspicions or give extra detail, but you'd be surprised just how much you can tell from just the energy trend over time.
On Thu, Nov 17, 2011 at 10:10:39PM +0000, Mark Rogers wrote:
On 17 November 2011 21:31, Chris Green <[1]cl@isbd.net> wrote:
I've never really understood the utility of any of the devices being promoted by the electricity companies which all (as far as I understand them) indicate your total electricity consumption. That's next to useless as it gives you no real clue as to what is actually eating your electricity.The key thing you get is usage against time. If I come home, put the oven on, eat, put the dishwasher on then settle in front of the telly, then look at the energy trend over that period, I'll get a pretty good idea of the relative usage of those appliances, and the background usage that runs throughout the night can be narrowed down pretty easily too. Of-course you'd want some appliance meters to confirm suspicions or give extra detail, but you'd be surprised just how much you can tell from just the energy trend over time.
I don't think our usage is that regular! :-)
I also suspect that the bulk of our electricity consumption is overnight as we try and do all of our washing, dishwashing, tumble-drying (when it's not dry outside) and water heating on economy7. Since the meter already tells us what we used overnight I can't see what further another meter is going to tell us.
During peak rates I think it's quite likely lighting that consumes most but as that's very random according to who is sitting where I can't really see what a 'spot' reading is going to tell us.
On 24/11/11 09:51, Chris Green wrote:
I don't think our usage is that regular! :-)
Well I'm sure mine isn't either!
I also suspect that the bulk of our electricity consumption is overnight as we try and do all of our washing, dishwashing, tumble-drying (when it's not dry outside) and water heating on economy7. Since the meter already tells us what we used overnight I can't see what further another meter is going to tell us.
It depends what you want to know. If you want the information, and if your appliances have timers, it would be fairly trivial to set the washing machine to start at midnight, the dishwasher at 2am, and so on, then look at how they compared. Or, for that matter, unless you do the same every night, comparing trends from one day to another will tell you a lot too (albeit you could do that with just the meter, but having the data collected for you so you only have to check it when you want to, rather than having to take meter readings manually every night).
During peak rates I think it's quite likely lighting that consumes most but as that's very random according to who is sitting where I can't really see what a 'spot' reading is going to tell us.
A spot reading won't tell you anything, but a sequence of spot readings should. For example, if you have some sudden spikes that'll tell you something different from a pretty much flatline trend. It might indeed just confirm what you already suspect, or it might give you some surprises.
In the grand scheme of things I don't see it saving us any real money; the cost of the kit might be covered by savings we can make by changing our usage or fixing some problems we didn't know we had, but if we get anything more than that back it's unlikey to be a good return on the time taken to investigate it. If I'm honest, my motivation is more curiosity and playing with the data on my Linux box than it is cost or environmental savings. But who knows? Making some fairly simple efforts to reduce water usage actually made a substantial difference to our bills, so the same is probably true here too.
On 24/11/11 10:18, Mark Rogers wrote:
In the grand scheme of things I don't see it saving us any real money; the cost of the kit might be covered by savings we can make by changing our usage or fixing some problems we didn't know we had, but if we get anything more than that back it's unlikey to be a good return on the time taken to investigate it. If I'm honest, my motivation is more curiosity and playing with the data on my Linux box than it is cost or environmental savings. But who knows? Making some fairly simple efforts to reduce water usage actually made a substantial difference to our bills, so the same is probably true here too.
When my one actually bloody worked I did find some savings...I had an idea that the stack of computer equipment in the study was costing a bit, when when I saw it added onto a running total for the house to sit idle it woke me up pretty fast.
I could have done that with plug in meters sure...but not seen the impact it made on the overall consumption of the household in realtime.
Realtime is also the key..you could take meter readings and eventually work out the saving of moving to CFL lighting or unplugging an idle computer...with Energy Monitoring you can see it in realtime room by room as you make changes.
I wouldn't have seen the faulty fridge that was costing me a fortune because with a build in appliance I had neither the thought or the ease of plugging in a socket based monitor.
I wouldn't have seen the faulty/unused and amazingly power hungry TV booster in the loft because I didn't know it was there (last house was rented) that was costing me 20 quid a year to do nothing ! Only found it when trying to track down the last bit of power sink in a house where I was sure everything was unplugged....so that alone paid for the monitor....then I think eventually I managed to shave over 100W from my "idle" consumption with little to no effort or cost...good saving.
On Thu, Nov 24, 2011 at 08:45:47PM +0000, Wayne Stallwood wrote:
I wouldn't have seen the faulty/unused and amazingly power hungry TV booster in the loft because I didn't know it was there (last house was rented) that was costing me 20 quid a year to do nothing ! Only found it when trying to track down the last bit of power sink in a house where I was sure everything was unplugged....so that alone paid for the monitor....then I think eventually I managed to shave over 100W from my "idle" consumption with little to no effort or cost...good saving.
That's why ours was so useful, being able to see what we were using helped us identify both usage patterns where we were wasting electricity and look at our overall consumption. Once you get to a certain level you know you can't reduce any more without changing appliances which isn't going to happen here until they fail and need replacement as the cost of that replacement doesn't cover the benefits. We found that with a bit of work we managed to make sure that certain appliances were no longer left on standby and a bit of jiggery pokery with our computing equipment meant we ended up saving nearly £100 a year. I've already got plans for saving a bit more energy but it means I need one of my routers to fail before it becomes cost effective as the saving will be about £50 a year but a replacement router is about £100.
Adam
On 24/11/11 21:14, Adam Bower wrote:
I've already got plans for saving a bit more energy but it means I need one of my routers to fail before it becomes cost effective as the saving will be about £50 a year but a replacement router is about £100.
If the replacement is about £100, presumably there's some resale value in the old one on eBay or elsewhere which might reduce the payback time?
On Mon, Nov 28, 2011 at 10:08:59AM +0000, Mark Rogers wrote:
If the replacement is about £100, presumably there's some resale value in the old one on eBay or elsewhere which might reduce the payback time?
There isn't much value in the kit as it's currently an old netgear dg834 with 3rd party firmware along with a couple of routers running openwrt, just I have 3 routers doing the work of 1 so I'd keep some of it as spare kit in case of hardware failure on the new.
Looking on ebay I'd get about £20 for the WRT54GL, a tenner for the Asus wl-500g and about 99p for the dg834.
The main benefits of upgrading this gear would be I could have 1 box and save a small amount of power and then get gigabit networking internally. The other reason I'm not upgrading yet is our exchange it supposed to get FTTC some time in the next year so I don't want to buy the "wrong" thing if circumstances change. As we are currently on the far end of a long bit of wet string buying a new router won't give us any more performance from our dsl line either.
Adam
On 17 November 2011 21:12, Wayne Stallwood ALUGlist@digimatic.co.uk wrote:
The current transformer needs to be attached to a cable carrying a single pole (Live) of a single phase...If you attach it to say a mains flex feeding a 4 way extension bar then the two poles (Live and Neutral) of a single phase in the flex have opposing fields and therefore cancel each other out.
That's a very good point, and I really should know better!
Since we're on the subject, is there a good reason why the CT should be put around the live feed from the main meter to the consumer unit, rather than the incoming live to the meter? It only fits around the latter...
On 17/11/11 22:05, Mark Rogers wrote:
Since we're on the subject, is there a good reason why the CT should be put around the live feed from the main meter to the consumer unit, rather than the incoming live to the meter? It only fits around the latter...
I don't see a technical problem and I think the advice with the meters comes from supply companies being rather twitchy about anything at all being messed with on the inbound power to the meter for obvious reasons.
Now a passive device it may be...but I think the instructions just go for the cautious approach as what is connected after the Meter and Supplier fuse is your business where as those devices and the cable attached to them belong to the supply network.
It's the same reason why they say you should seek approval before attaching the "magic eye" to the meters for the optical reading type of installation...they aren't your meters.
On 24/11/11 20:52, Wayne Stallwood wrote:
I don't see a technical problem and I think the advice with the meters comes from supply companies being rather twitchy about anything at all being messed with on the inbound power to the meter for obvious reasons.
I figured as much.
I'll probably get a letter from them next time they read the meter!
On 28/11/11 10:07, Mark Rogers wrote:
On 24/11/11 20:52, Wayne Stallwood wrote:
I don't see a technical problem and I think the advice with the meters comes from supply companies being rather twitchy about anything at all being messed with on the inbound power to the meter for obvious reasons.
I figured as much.
I'll probably get a letter from them next time they read the meter!
I doubt it....Meter reading is mostly contracted out now and the people doing it mostly likely don't know what to look for or care enough to look. Even if it did get noticed I bet they have seen enough of those CT's attached now (hell even some of the suppliers are providing them) to disregard them.
I think maybe the light pickups could get you in trouble...surely the optical interface is there for a meter reader to do a point and shoot reading and you'll block it with the stick on thing ?
On Wed, Nov 30, 2011 at 12:19:41AM +0000, Wayne Stallwood wrote:
I doubt it....Meter reading is mostly contracted out now and the people doing it mostly likely don't know what to look for or care enough to look. Even if it did get noticed I bet they have seen enough of those CT's attached now (hell even some of the suppliers are providing them) to disregard them.
I had my current cost disconnected mysteriously one day and a few days later I got an electricity bill. Although this was a few years ago when they were quite new.
Adam
On 30/11/11 00:19, Wayne Stallwood wrote:
I think maybe the light pickups could get you in trouble...surely the optical interface is there for a meter reader to do a point and shoot reading and you'll block it with the stick on thing ?
I assumed the light interface was just a pulse counter, ie useful for counting the energy as it's used, but not useful for taking the current reading?
On 30/11/11 10:30, Mark Rogers wrote:
I assumed the light interface was just a pulse counter, ie useful for counting the energy as it's used, but not useful for taking the current reading?
The ones I have seen support a two way conversation that supports taking a full reading and even reprogramming some features of the meter, Although I have heard that some of this functionality may be password protected. I think when they recieve no requests they perhaps fall back to the unit count mode.
Communication runs at 300 baud and perhaps inventive people could convince IRDA hardware to talk to it if they were so inclined in a purely investigative and non fraudulent manner.
I think they mostly use IEC1107 which means you could just pay BSI for a copy of the documented transmission protocol. If you wanted to take a look then I would try and obtain a copy of BS EN 62056-21.
On 14/11/11 11:23:31, Mark Rogers wrote:
I'd like to play with one of the various energy monitoring gadgets that seem to be everywhere these days. I'm looking for one that will transfer data to my PC, and obviously that PC is running Linux (Ubuntu 11.04 at the moment, not sure if it will go to 11.10 yet...)
Any suggestions/recommendations?
I'm as lazy as they come so ideally I'm looking for something that can be permanently connected to my PC (therefore presumably a wireless connection will be involved at some point); I don't really want a box that collects data that I then take to my PC to download it once a week/ month/year/never. And I'm also looking for access to the raw data, but also suggestions for suitable GUIs welcome too.
I've had a CurrentCost meter for some years now which I believe is called the Classic. It does have a USB lead and is connected to my computer (Debian Testing). Soon after I aquired it I found some software which saved data into a database and provided graphing facilities.
http://code.google.com/p/currentcostgui/
Unfortunately the Live data part of it doesn't work under Linux. It crashes usually before it's plotted anything and a number of other users have reported the same problem. The developer suggested it was a problem with one of the linux libraries but he has stopped developing/supporting it now anyway. I don't understand Python so haven't been able to do anything about it.
Just today I managed to find enough information to enable me to cobble something together using Perl and rrdtool to produce a graph to show our live data usage. We have a two phase supply which complicates things a little but I have been able to plot both phases (different lines) on the same graph.
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Adam Bower -
Barry Samuels -
Chris Green -
Mark Rogers -
Wayne Stallwood