Energy Meter use or ornament?

[DetlefSchmitz]

Our Wattson was mostly for fun. It does give you a good idea of the kind of pattern of power usage and makes everyone aware of the background load. These days we use it by waiting till we are exporting a kW or so and then turning on the dishwasher, or something similar.

 

[DetlefSchmitz]

i also experiment
which is quickest which is cheapest
a 900w microwave and a mug off water
or the same mug off water in a 2750 kettle
answers please

Please don't tell me it's the kettle!

 

[big-all]

afraid so lol both quicker and cheaper
kettle 39seconds at 2890w
2.20/140seconds at 1450w

 

[winston1]

i also experiment
which is quickest which is cheapest
a 900w microwave and a mug off water
or the same mug off water in a 2750 kettle
answers please

Please don't tell me it's the kettle!

Definitely going to be the kettle.
All the input power in a kettle goes into the water. There will be slight losses from the case of the kettle.

My microwave, which I'm sure is typical, input power 1080w, output power 700w. There will still be slight additional losses from the mug.

 

[ban-all-sheds]

Basic fact if we use something electric it costs, so only use what we need, does not need an energy meter. Or have I missed something, is there really some point testing out appliances to see how much they use?

Must admit, when I first had it, I used to watch the figures change when I put the kettle on etc, but now completely ignore it. In fact, if anyone wants it and lives near Derby, please feel free to call in and collect it.

This is what I just don't get about these things.
Presumably you already knew that boiling a kettle would use electricity? And presumably you didn't boil it up just for fun?
So how is a monitor going to help you use less electricity when using your kettle?
And the same applies to everything else - unless someone is so thick that they don't realise that electrical appliances use electricity and/or are in the habit of leaving the shower running, or keeping the oven on just in case, or drinking more cups of tea than they actually want etc, what's a monitor going to do for them?

But what do they use them for?
"Oh look - my tumble drier is expensive to run"?
"Blimey - who'd have though that turning off lights in empty rooms would save money"?

I'm thinking about getting my parents an Owl energy monitor as they are concerned about their bills

Just get into the habit of turning off anything not needed, don't fill the kettle when you only want 2 mugs etc.
Knowing that your tumble drier costs 35p an hour to run doesn't help you save money if you need to use your tumble drier.

I've never understood the idea that unless you monitor your usage you won't think to turn things off when they aren't needed.

No - sorry - I still simply don't get it. I cannot see why people need a monitor to tell them to switch things off which they are not using.

 

[JohnD]

No - sorry - I still simply don't get it. I cannot see why people need a monitor to tell them to switch things off which they are not using.

Perhaps because most people were not born with an inherent understanding of the relative energy cost of different appliances.

For example there are still people who think that turning off a lamp, or unplugging a phone charger, will make a discernible difference, or that it is cheaper to wash up by hand than in a dishwasher.

I used to have an old fridge and an old freezer. When I changed to new, my daily usage and electricity bill dropped significantly. The same happened with the washer and drier. If I had realised the cost of running the old appliances, I might have changed sooner and recouped the purchase price.

 

[ban-all-sheds]

kettle 39seconds at 2890w

Either you're using water from the hot tap, or you're not actually boiling it. With absolutely no losses - no energy being used up heating any part of the kettle, or heat being lost out of it during the process, that amount of energy is sufficient to raise exactly 300ml of water (i.e. no little bit extra in the kettle at all) by 90°C.

I can't see how it's enough in practice (given that there will be losses) to bring a mugful of water to a boil.

 

[Iggifer]

What temperature water are you expecting him to be using? 1-4°C? I'd wager room temperature

 

[big-all]

245ml in the cup 5mm below the rim cold water tap near to room temperature about 15 at a guess
definately boiling after 37 seconds
the actual results can have 10% cumulative error it dos'nt matter with my microwave an my kettle its both faster and cheaper
the kettle may have some residual heat but unlikely from over an hour earlier
the base off the kettle is 6"circumference metal base with all plastic cover
the amount off water inside is only about 6mm deep
http://www.argos.co.uk/static/Product/partNumber/9098422.htm

 

[ban-all-sheds]

What temperature water are you expecting him to be using? 1-4°C?

No - more like 5 - 10°, at this time of year, fresh from the cold tap.

And when he said a mug full, I thought he meant a mug full - i.e. 300ml at least.

 

[JohnD]

but presumably the experiment tested with the same amount of water in both methods, starting at the same temperature, so it does not really matter, as it was to find which used less energy.

kettle 39seconds at 2890w
mwave 140seconds at 1450w

edited
I make it
112710 W/s
203000 W/s

 

[ban-all-sheds]

but presumably the experiment tested with the same amount of water in both methods, starting at the same temperature.

One would hope so.

 

[stillp]

Did they finish at the same temperature though? Hard to measure inside a microwave oven.

 

[JohnD]

definitely boiling

very likely the temp was about 100C

 

[big-all]

same cup same amount same plug in monitor about 5 mins apart kettle first then microwave so same cold cup
its possible the micro water was a fraction colder but unlikely to effect the overall outcome
yes its possible i presses the start button on the stopwatch a couple off seconds after the turning the kettle on but that all its also possible the monitor is out but it doesnt matter in this instance as it comparson test rather than an accuracy test