Electricity monitors

[RF Lighting]

My parents recently had a scare over their electric bill due to the digits of one of their meter readings getting transposed. As a result they have become much more conscious of their electricity usage.

As a result they'd like a meter which shows how much power is being consumed.

I know there are loads of different ones on the market and that some of them can give wildly inaccurate readings.

Has anyone had any experience of these devices? And if so what would you recommend?

 

[scotsgraeme]

I have a current cost envi monitor, seems to be pretty accurate, certainly within a couple of quid of the bill when i've checked, but we mostly use it to see if we've remembered to switch things off, to get an idea of how much we're wasting with the little one leaving ALL the lights in the house on, etc.

 

[winston1]

My parents recently had a scare over their electric bill due to the digits of one of their meter readings getting transposed. As a result they have become much more conscious of their electricity usage.

As a result they'd like a meter which shows how much power is being consumed.

I know there are loads of different ones on the market and that some of them can give wildly inaccurate readings.

Has anyone had any experience of these devices? And if so what would you recommend?

The most accurate one is the one already there next to the CU.

ALL the others do not measure power. They measure current and guess power by using an assumed fixed voltage and assumed unity power factor, neither of which ever exist in practice.

 

[ericmark]

Scottish Power gave us one which works well enough to show total power used. But also used a plug in type and tried many items around the house to see what power was used.

However in the main knowing the Sky box on stand-by still uses 12W not 1W as the industrial standard requires for stand-by may mean we will turn off when not in use but in real terms since it stops it recording programs it is simply not done.

The same with Fridge and Freezer we may realise it is using 600 kWh/annum rather than 260 kWh/annum for a new one but spending out £500 for a new energy efficient one with a guarantee of just 2 years and likely will last 5 years just does not make economic sense.

I found one fault which was corrected. I found my mothers freezer was not switching off. On further tests found -25°C so new thermostat fitted. But this was the only action taken after measuring loads of items to see what they used that really helped both in power used and stopping my mother finding cold bits in the microwaved meals.

As to the Scottish power meter it has not helped at all. I know what I am using but that does not help me use less.

 

[big-all]

to me a plug in monitor will be more useful
then you can work out what uses the most energy
changing "normal" or halogen bulbs to led are likely to give the greatest savings
it costs around 1p per watt at 14p a unit for a week at an average off 10 hrs a day
so swap say 4x60w down lighters for 5w led thats 55x4=220w per week or £2.20 a week saving

i have a samsung and a sony tv both the same size found out the sony uses around 100w the samsung uses 44w swapped the tvs round save £25- 40 for the same viewing pattern

 

[ban-all-sheds]

As a result they'd like a meter which shows how much power is being consumed.

Do they need a meter to tell them that they have left things on which they could easily not?

Do they leave things on which they could easily not?

to me a plug in monitor will be more useful

Except for things which are not plugged in. Like lights.

then you can work out what uses the most energy
changing "normal" or halogen bulbs to led are likely to give the greatest savings

Do people need monitors to tell them that LED or CFL lighting uses less electricity than halogen?

i have a samsung and a sony tv both the same size found out the sony uses around 100w the samsung uses 44w swapped the tvs round save £25- 40 for the same viewing pattern

OK - now that was a useful discovery, but in the main people don't have a selection of washing machines, tumble driers, cookers, fridges, showers etc to swap around like that. And as Eric said - replacing a particularly power-hungry appliance for a better one just to reduce running costs does not make sense.

 

[ban-all-sheds]

The most accurate one is the one already there next to the CU.

ALL the others do not measure power. They measure current and guess power by using an assumed fixed voltage and assumed unity power factor, neither of which ever exist in practice.

I would be very surprised to learn that domestic electricity meters concern themselves with PF.

 

[JohnD]

I use an Owl 160 which was one of the "Which" best buys. It has a USB connector and will copy data onto a PC so you can look at graphs if you want. I think the memory in the owl holds a three-month record and the PC seems to be an indefinite period, you can look per year/month/day/minute or have a scrolling 3-minute display.

Once you are used to the display, you can spot if e.g. an electric heater has been left on.

It is battery powered and portable so you can leave it by the bed if you want, you can easily see if anything has been left switched on.

You can set an "alarm" level which will bleep and/or flash if usage goes above a level of your choice. I would say it is accurate to within a few hundred watts.

 

[big-all]

a floor lamp or table lamp without a dimmer for checking bulbs
swapping tvs was just an example as what to look for
on most modern electronics power saving on off or standby a virtually the same
but iff you have a steam powered tv or radio it could be worth replacing or at least worth unplugging when not in use

using a kettle is cheaper to boil a cup off water over a microwave assuming the kettle can boil just a cup full

my washing machine in a week will use more on standby than a 60 degree 60min full wash and its less than 3 year old

to me its all value over effort

 

[ericmark]

my washing machine in a week will use more on standby than a 60 degree 60min full wash and its less than 3 year old

This like my Sky box is an eye opener. However in the main we switch on a washing machine and leave it. We take out the cloths at our leisure and for what it uses on stand by I would not be popping into the kitchen every 5 minutes to check.

I would say re-chargeable batteries are the largest waste of power in my house. I charge them ready, then don't use them, then find them flat, then charge the ready.

After doing careful measurements with the fridge/freezer I looked to the washing machine. It has a host of programs and I am sure each one has a different power requirement. But the machine weighs the load so unless I was to wash the same things with every cycle near impossible to work out costs. And if I do will it make any difference?

Best money saving appliance is the car port. One can put out the washing it dries in the wind but does not get wet when it rains. I really miss the car port. Garage is no where near as good just gets filled with junk.

But we all know where the money goes. My wife fills the tumble drier and I say "Ha do you realise how much that costs?" answer is yes 3 units at 14p each that's 42p if you think I am hanging out the cloths to save 42p you have another think coming.

She is of course right she's bigger than me. So also points out how much it costs in washing tablets and washing machine costs to re-wash anything which gets dirty on the line and my bird feeders do not help.

In the main we don't need energy meters. My tumble drier is plainly marked 1 kW low power 2 kW high power and 0 - 90 minutes on timer. OK some people have cleaver ones which measure the humidity of the load and auto stop. But hang on 42p a load how many loads will it need to pay for that technology? Plus mother has it on her washer/drier and the amount of times I have to switch it back on the drying cycle I have lost count.

As to the cost of the tumble drier pumping outside my centrally heated air that is something else. Never mind the fact we have an open flue fire.

To buy replacement energy efficient equipment when the old one fails OK. But to change equipment that's something else. My boiler is over 25 years old and going strong. Mothers last boiler lasted 7 years, Sons lasted 5 years, daughters lasted 8 years, why the heck should I get rid of such a reliable unit? We are not only talking about the £500 for new boiler but also the weeks in the cold before it was renewed.

It's simple if not broken then don't fix it!

 

[winston1]

The most accurate one is the one already there next to the CU.

ALL the others do not measure power. They measure current and guess power by using an assumed fixed voltage and assumed unity power factor, neither of which ever exist in practice.

I would be very surprised to learn that domestic electricity meters concern themselves with PF.

Well you learn something every day. Domestic electricity meters monitor voltage and current and measure true power not VA.

 

[winston1]

I use an Owl 160 which was one of the "Which" best buys. I would say it is accurate to within a few hundred watts.

Which only goes to show "Which" researchers know nothing about electrical engineering.

The Owl does not measure watts. It measures current and guesses. Try loading it with a large capacitor. We all know a capacitor takes wattles current. Not the Owl though which will indicate power being consumed.

 

[RF Lighting]

Can you provide a link to one which does measure watts which can sit in my parents living room? Or are you just going to criticise the posts of people who are actually trying to help me?

 

[winston1]

Can you provide a link to one which does measure watts which can sit in my parents living room? Or are you just going to criticise the posts of people who are actually trying to help me?

No. No one makes one.

There are plug in ones but you can't plug your parents whole house into it.

No need for that rude comment at the end.

So called energy monitors are not as described or fit for the purpose for which they are sold.

 

[RF Lighting]

So you've got nothing useful to add as per usual. Do you actually understand the concept of an energy monitor? My parents want something to give them an idea of how much electricity they're using, so if they are consuming an unusually large amount they can investigate why for example.

It does not need to be accurate to the mW.

I think the owl looks like a good unit. I'll probably go with one of those.