How can I find out how much power appliances use?

Ben84

Martyn1981 wrote: »

I know we live in a wasteful, throw away world, but people often forget energy consumption when proudly referring to their 20 year old telly, boiler, fridge or freezer. Especially when fridges/freezers start to run too much, or continuously.

Old TVs are usually pretty good actually. From the late 70s onwards, thanks to increasing use of microchips, their energy use fell a lot. My 26" colour set from 1981 uses about 55-75W, which is tiny really, probably adds up to a single kWh a month in our household. Some modern TV types will use less energy per square inch of screen space, but the trend towards giant TVs is likely causing the average TV to use more rather than less energy.

However, I have a similar age fridge, and that is very energy hungry compared to same size new ones. But as before, watch out for the latest giant size fridges, some of them claim high efficiency, but still consume vast amounts of energy due to being huge. I could trade in my under counter fridge from about 1980 for a new wardrobe-size American fridge and end up using more energy. I could however save a lot with a new under counter fridge.

As for boilers, the claimed efficiency of old boilers in the SEDBUK database relies on some assumptions you may or may not agree with. The main thing is that anything with a standing pilot light gets 65% by default. However, my back boiler, when I work out the heat input and output from the figures in the manual is about 80% efficient. This figure doesn't account for the pilot light consumption - but why assume the pilot light heat completely vanishes? The manual figure ignores it, the SEBDUK figure may be greatly over estimating its effect. Personally, I suspect somewhere between the two extremes. With the large volume of air in the boiler/chimney and large surface area of chimney between the pilot light and the top of the chimney, I expect the majority of the heat it emits dissipates in to the house, where it's useful during winter at least.

Anyway, I'm not saying new appliances can't be very efficient, just watch out for total figures as appliance size matters, and be cautious about some of the claims. Some things will use more, others not that much less than the current one. I have pretty low bills despite owning mostly old appliances. Aside from the reasons mentioned, I think their typically smaller sizes and lack of standby settings tend to help as well.

Dave_Fowler

Martyn1981 wrote: »

I know we live in a wasteful, throw away world, but people often forget energy consumption when proudly referring to their 20 year old telly, boiler, fridge or freezer. Especially when fridges/freezers start to run too much, or continuously.

That looks like a 'saving' of 2.5kWhs per day, or about £100 to £150 pa. Wowza. There won't be much left for your PV to do!


Mart.

The freezer has now been installed for 67 days and, according to the power meter, has consumed 30.7kWh. This compares with 199kWh that the old freezer would have used. This equates to a saving of 917 kWh per year! The money saved will pay for the new freezer in 2.5 years.

Without the power meter I would never have found out these figures.

Time now to check the consumption of the two fridges!

Dave F

Kernel_Sanders

My plug in monitor paid for itself in weeks as I discovered that my 1982 clock radio cassette was using nearly a kWh every day when only displaying the time !

Dave_Fowler

Kernel_Sanders wrote: »

My plug in monitor paid for itself in weeks as I discovered that my 1982 clock radio cassette was using nearly a kWh every day when only displaying the time !

Wow! around 40 watts constant. Was it a large LED display? You'd think the cabinet would have been quite warm with all that power to dissipate.

Dave F

theboylard

New toy alert!!! New toy alert!!!

Just seen this over on openenergymonitor dot org and thought this was very interesting....

http://www.smappee.com/uk/ I want, I think?!

lstar337

theboylard wrote: »

New toy alert!!! New toy alert!!!

Just seen this over on openenergymonitor dot org and thought this was very interesting....

http://www.smappee.com/uk/ I want, I think?!

How does the single sensor monitor individual appliances?

Can't see anything that explains this on their site.

Looks like a standard energy monitor with an iPhone interface, nothing more.

lstar337

Can Smappee detect all my appliances?

Once connected, Smappee starts to hunt down the appliances in your home. After a couple of hours, your first appliances will be recognized. As Smappee gets to know your home better, new appliances are being detected in the next days. A limited number of appliances remain harder to detect though. For those appliances, Smappee will either need more time or won’t be able to recognize them.

theboylard

Smappee looks for and creates "electrical fingerprints" for each device.
Some things it will find automatically, others you may have to turn the device off, set smappee to "listen" for a new device being turned on, then turn that devive on. Smappee will then add that devices hopefully unique fingerprint to its list for your property.

I must say it looks really interesting. I've fired over acouple of questions and we'll see what comes back.

From the FAQ though:
Smappee uses highly innovative software which analyses the measured current. This is how Smappee tracks which appliances are switched on and off, and when.

Dave_Fowler

I've also dropped them a question about if the Smappee can work with two (or more) sets of solar panels on separate connections to the fuse box.

The_Green_Hornet

Here is a review which gives a bit more information on how it detects devices. It is in Flemish so you will have to let Google translate it for you.

http://www.fwdmagazine.be/fwd/152849/review-smappee-energiemonitor/

The conclusion is that the detection and identification of devices needs to be more reliable and easier.