Adventures in Home Energy Monitoring or “How I Became the Energy Enforcer”
September 18, 2009 at 12:45 pm monkchips 20 comments
a guest post by homecamper and Quest Software guy Joe Baguley.
It all started one drunken night a few years ago with my neighbours in the garden (as do most life-changing events I’m assured). It appeared that they were all paying an awful lot less for their electricity than me which I found confusing as we lived in similar houses.
Electrisave
After some investigation I discovered the Electrisave (since rebranded as the OWL). £45 later and I had fitted the clamp ammeter to my main feed into the house and was going round the house switching things on and off to see how much they cost. Hours of endless fun, no seriously!
I quickly worked out that my house idled at about 3.4p/hr unless the fridge/freezer was cycling when it hit 5.5p/hr. This small nugget alone dramatically changed household behaviour. Everyone was trained that as we went to sleep, or before we left the house, to check the meter. If it was more than 5.5p/hr then something was on that shouldn’t be and was switched on. Already my bills started to drop by about £10-£15/month.
Then one night I am sitting by the TV, with the meter in front of me (I became sadly obsessed) when it jumped up by 30p/hr to my amazement, something that I thought only the fridge or kettle could do for me, but neither was on. Some investigative work led me to the immersion heater (no gas water heating) and further playing showed me that the cams were worn on the mechanical timer and the thing was never turning off. One new electronic timer later and my bill dropped by a further £30/month and suddenly I was paying less than my neighbours. They were now borrowing my meter to wonder around their homes discovering savings.
Within less than 2 months the unit paid for itself.
Wattson
Ever on the lookout for new gadgets I discovered Wattson and purchased one of their first devices. This did much the same as my Electrisave, but this time allowed me to capture and graph the data using their rather cumbersome app. Now I had usage graphs and could track trends, associating activities with expense. Now I was really starting to annoy my family.
I played with that for a long time, now further rewiring both my study and TV ‘complex’ to ensure that I could switch as much off as possible ‘at the wall’ when I could, leaving only ‘essential services’ powered on 24/7 (Sky+, Cable Modem, NAS drive etc.)
The only problem with the Wattson was that though it glowed pretty colours, the display would show you your ‘estimated bill for the year’ based on current usage, so the thing fluctuated from £350-£4000 as stuff went on and off, but was to abstracted from reality to be useful to drive behaviour with the family compared to the cost/hour of the previous solution.
I was however generally happy with the Wattson, but felt that I needed more info…
GEO
So, along came an Eco show at the Earl’s Court and the discovery of Green Energy Options and their home monitoring plans. They included not only monitoring to an individual device level, but were also looking at my other big and untrackable expense – gas.
So, I begged to get on their beta trial, even though I was well outside their trial area (East Anglia) and through some stroke of luck I was accepted.
I opted for the top of the line unit, the Trio+ at £250 (discounted for the trial) because that was the one that gave me detailed reporting to a device level and included gas.
So a couple of weeks later 2 chaps showed up in my house, placed clamp ammeters about everywhere possible in my consumer unit (fuse box) and installed individual appliance monitors on everything I thought appropriate in the house (washing machine, tumble dryer, dishwasher, kettle, TV etc.)
The best piece of it all was that the data was all collected onto an EeePC running MySQL, Apache and their own Flash interface which is beautiful and well thought out. More importantly as it is a webserver I can view my house (and turn things on and off) from ‘anywhere’ after opening port 80 on my router and doing the redirect. Here are some sample screenshots:
The number of screens and ways you can view the data are fantastic.
The gas monitoring I am assured will be coming in the next couple of months, but for now the electricity detail is great. The fact it measures cost over time as opposed to one fixed point means you can learn a LOT:
- I now know my dishwasher costs 16p/cycle, compared to my washing machine at 7p, and that running it on the thermonuclear remove the spot-welded lasagne from the dish mode only takes it to 17p. Best suggestion I have had yet is to get all plastic plates and cutlery and wash them in the washing machine. Instead we don’t put the dishwasher on part-full anymore.
- My kettle was costing us near on 50p/week, whereas my new ‘on demand’ model costs us about 6p/week
- The oven is no longer left on for 30-40 mins to ‘warm up’, neither is the kettle left for 20 mins to ‘warm up’. These things get hot very quickly nowadays.
- Taking into account both the cost of food and energy used in cooking it, the chip shop is wallet friendly in some cases…
- My ‘little 3kW pool heater’ we use in the summer for our 10’ pool costs about £9/day to run – kids now cope with it a little colder than 33C…
- My 40” Sony LCD TV costs hardly anything to run (60-70p/week) – fabulous
- The over 1500W of GU10 spotlights downstairs are killing us, and we are trying to find acceptable either CFL or LED replacements, none found yet but some are on their way to me this week to try.
- Laptop power supplies left plugged in are a BAD thing.
- My wife hates it when I am travelling and phone her up to complain about the amount of TV she has been watching instead of doing the housework…
- My kids know that I can turn their TV off from anywhere in the world…
My next big step? – gas monitoring when they fit it. I will finally be able to answer the question this winter as to whether leaving the heating on all the time on a thermostat or turning it off at night and then reheating the house in the morning is best.
Footnote: What drove me to do all this was not only a fascination with tech, but more importantly a fascination with not wasting money. Not saving the planet – saving cash. In my experience cash beats morality every time…
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1.
Prof Steve Bagukley | September 18, 2009 at 2:47 pm
Pity he did not do this for the 20 plus years he lived at our house, the only way he saved energy then was to lie on the settee and wach me mow the lawns! He neven opened his bedroom curtains as it was easier to reach out of bed and turn on the light.
2.
Joe B | September 18, 2009 at 3:06 pm
I suppose that’s the difference that now having to pay the bills makes.
3.
Gabriele B | September 18, 2009 at 3:18 pm
Funny: my father would have said exactly the same.
I was lucky anyway: the curtains were always left open in my house so, no need to reach the light!
4.
Shrewd Mammal | September 18, 2009 at 3:20 pm
Now THAT is a quality comment Prof, talk about pwnd Jo (Good article by the way mate) lol, I’m glad my dad does not do the internet thing….oh wait….
5.
Terence Eden | September 18, 2009 at 3:48 pm
The problem with gas monitors is that they only measure hot water usage. Which is fine if you have radiators and don’t cook with gas.
I was always told that you should keep the hot water tank heated at all times – it’s better to keep it hot all day than boil a whole tank every morning / evening. I guess it depends on how efficient your boiler is and how well insulated your tank is.
I’m getting a little obsessed with my GEO Duet. I like your idea of showing cost rather than kWh.
The other thing I recommend – to get your costs down – is switch energy provider. Your current one should be able to tell you how many kWh you use in gas and electricity. I’ve move from a tarrif which would have cost £1,200 to one which should cost ~£850 (assuming price and usage stays the same).
6.
Joe B | September 18, 2009 at 3:57 pm
The thermocouple on hot water pipes thing is a start, but you are right in that I am disappointed that it will not show me usage of my hob and of my nice gas fire.
There is an RJ11 socket on the bottom of my gas meter which closes pins 3 and 4 every cu/ft or cu/m which would be the perfect measure, we need to be using that as an input.
I have pointed this out to GEO, but I think the gas companies don’t like it… They will have to wise up soon.
7.
Claire Sale | September 18, 2009 at 3:58 pm
Hey Joe– glad you’re enjoying your trio. We’ll have gas monitors in October… not long now!
8. links for 2009-09-18 « The Adventures of Geekgirl | September 19, 2009 at 2:05 am
[...] Adventures in Home Energy Monitoring or “How I Became the Energy Enforcer” « Home Camp (tags: energy power home consumption monitoring appliances carbon fuel saving utilities) [...]
9. Humm Duet – Speedometer – Terence Eden's Blog | September 21, 2009 at 9:02 pm
[...] Joe Baguley points out in his article about the Humm Trio, understanding the read-out makes it easier to understand what’s going on. I now know my [...]
10.
Ken Boak | September 22, 2009 at 3:20 pm
Joe,
Thanks for the update. I heard you speak at HomeCamp 09, and I am pleased to hear that the kit you have installed is helping you make energy savings.
The problem with gasmeters is that they are all different, and only the more modern ones have any facility for a pulse output. As you have an RJ11 (R5 port) on your meter, that’s half the battle.
It would be relatively simple to get an Arduino or similar to count the pulses and get them up to the net using an Ethernet shield.
However, the gas utility generally frown on any suspicious devices connected to their meters, and from a legal point of view, any equipment connected to the meter has to be shown to be intrinsically safe, and meet quite stringent safety regulaltions.
In the late 1990s, I developed a wireless pulse counter which sent out the accumulated pulse count out on a simple low power 433MHz link. It was battery powerered from a lithium AA cell, but certified that it could not develop a fault which could ignite a gas/air mixture or lead to an ignition temperature. That was the real challenge and the design had to be tested and certified by BASEEFA – a costly exercise, even for a small company let alone an individual.
IMHO its the safety regulatory requirements surrounding gas meter devices that is restricting the development of gas monitoring solutions.
As a second point, regarding your comment for gas consumption for heating a typical house, is it cheaper to keep the heating on all day 24/7 at a low setting or have it come on twice a day?
This I believe is entirely down to the construction (ie age) of the property. I have found that with my 1905 brick-built semi, with solid 9″ walls that it is cheaper and more comfortable to keep the heating on 24/7 in winter, at an approximate power of 6kW, than to blast it for a couple of hours at 24kW in the morning and 4 hours in the evening. This is solely down to the high thermal capacity of the walls which need to be brought up to temperature and then maintained so.
For a modern, well insulated house with low thermal mass plasterboard partition walls, the converse is likely to be true. As I see it, you only have to heat the air in the room and then the insulation helps maintain the room at temperature.
Using this approach, I managed to shave off 6000kWh of gas per year, bringing my 19000kWh bill down to 13000.
Whilst this might appear contentious, it’s what I have found after 9 years of energy monitoring in this property.
11.
Joe B | September 22, 2009 at 4:51 pm
Ken,
If it was you that spoke, I remember your talk on gas and it was inspiring.
I am talking to the CTO of GEO about pulse monitoring, but I think your point about stringent safety regulations will apply. My last inspection the guy from Southern Electric got really upset because I have a power and ethernet cable running across my main gas feed pipe!!! (about 2 metres from the meter no-less).
I could always hack it together myself, and may well do so (I have a couple of the Current Cost pulse counters) but I would really like it integrated with the GEO.
I am really intrigued about the leave-on-all-the-time, vs morning blast methods. My house is 1970s insulated walls and brick internal walls, so will be interesting to see.
The gas monitoring GEO use is a thermocouple on the output of the boiler (as terence says), thereby monitoring hot water and heating in my house, so will be a reasonable measure I think, and hopefully enough for me to make a comparison. The only unmetered heating variable is the lovely ‘pretty’ gas fire my wife likes to use in the lounge…
12.
Ken Boak | September 23, 2009 at 12:33 pm
Hi Joe – yes it was me that spoke on gas monitoring. My involvement was between 1998 and 2002 but the industry is not much further on since then.
The regulations are stringent and the gas industry takes them seriously. They treat the whole volume around the meter as a potentially explosive atmosphere, where there must be no source of spark, ignition or overheating component that could potentially cause ignition.
How they can enforce this in properties where the gas and electricity meters share the same cupboard and illuminated with a 100W bub – I don’t know!
Needless to say the hardware to read a pulse output is trivial – the cost of regulatory approvals is not.
I recently found some 1mm fibre optic cable that can be purchased from the likes of Farnell. It would be possible to make an opto sensing device that used several metres of fibre optic cable to convey the LED light to the reflective target and then back to a remotely located photodiode thus keeping all electric wiring well away from the meter.
If you are fortunate enough to have an RJ11 connector on the bottom of your meter, then a LED and a couple of duracells or a 3V coincell and a suitable series resistor would make a 1 way optical output.
The thermocouple method would need to have thermocouples on both the flow and return pipes to the boiler and preferably with a flow meter fitted inline – so that the temperature difference and the flow rate of water could be measured to give a more accurate figure for boiler output power and thus gas consumed.
I found that those decorative gas fires are extremely wasteful in gas, and a radiant gas fire or a boiler with pilot light can use 6kWh a day in gas on the pilot alone!
13.
Terence Eden | September 23, 2009 at 1:26 pm
Are you not over-complicating it slightly?
1) Get an IP camera with InfraRed vision
2) Stick it in front of your gas meter,
3) Have it automatically FTP an image of the meter reading every 15 minutes (or whatever level of precision you want).
4) Run OCR on the images
5) Or simply display the live stream of your meter whirling away.
Hey presto – an ersatz meter reader which doesn’t interfere with the gas equipment.
I got an all-singing all-dancing camera for £150, but a basic WiFi model is usually under £50.
T