Best plug-in energy monitor?

[linesrg]

Guys,

Only £150 a quarter, you were lucky (in the words of the old Monty Python sketch).

I hope you're all sitting down as we're running at £80 a month!!!!!!! We have new (in the last twelve months) A+ rated fridge/ freezers, we have energy efficient lighting everywhere (OK except the bathroom/ shower room and I'm working on those). We have an A rated dishwasher ( supposedly more efficient than washing up?).

Having a boiler that runs 24/ 7 means we have a Grundfos pump burning and churning all day long and, with the fitting of the UFH to the kitchen, the other UFH circulating Grundfos does it's fair share of watt burning as well.

The ball breaker is the washing machine and tumble drier without a doubt. It's amazing how much washing two adults and two children can generate.

I take the boys swimming on a Sunday morning and we need to get towels washed and dried for the boys swimming via school later in the week. There is only one way to get them done in time.....

As for the suggestion re replacing halogens with LED light's as above, as I've commented elsewhere, this is not a cheap option. Here are some figures for you to contemplate.

When we bought our Brilux 2 x 3W LED GU10 lamps (50W halogen equivalents) they cost us about £18 + VAT as we bought 20 of them. Recently I enquired of the UK importer for the costs of buying some in bulk with a view to re-sale via the likes of eBay. The price to me from the UK importer would be £18.25 + VAT. By the time you've added the eBay and PayPal costs you need to sell the device at £23.75 just to stand still. Importing them direct from China in lots of 500 would only enable you to sell them at £18.15 to stand still. Ironically the firm we bought our first lot off don't appear to sell them anymore. www.besthongkong.com seem to be the cheapest source of such things I can find - they manufacture and sell them.

Regards

Richard

[wookey]

Why is the boiler running all the time? Shouldn't it be off for at least part of the night? Probably worth paying for modulating pumps if you are running them nearly all the time. An 80W pump all year costs £98 to run (@14p/unit). That makes it easy to justify a £150 modulating one if it can get the average down to say 40W (pays for itself in 3 years). No idea if those numbers are right but those are the sorts of sums to do.

Maybe you should just buy buy 3 more towels per child (£not much) then each towel would get a couple of weeks to dry, not a few hours. Pay for itself in about 3 weeks I imagine (I assume you do have access to a washing line?). Tumble-driers are something that really should be avoided except in genuine emergencies and maybe the dankest time of the year - if you've arranged life so that every week is an emergency then you're not doing it right.

No, LEDs are not yet cheap (to buy), but then halogens are very expensive to run. But quoting cost-to-buy only is meaningless. You have to compare with running costs to see if it makes (financial) sense (it clearly makes efficiency sense). Right now converting to CFLs is much cheaper and still provides ~70% of the LED savings so that's the way to go for people that don't want to spend much money up front, especially as you can get the bulbs for free.

Some quick payback sums. UK average consumption per year is 780kWh/yr on lighting. ( http://iaeel.org/IAEEL/Archive/Right_Light_Proceedings/Proceedings_body/BOK4/RL4japal.pdf ) that's £84/yr. Let's say it's done with 10 60W bulbs on for 1300hrs each on average, for estimation purposes. Obviously some will be on a great deal and some will only be on occaisionally. That's 420 lumens each.
Do the same lighting with CFL's throughout (costs 10*£3 =£30 to replace), uses ~140kWh, or £20.
Do it with LEDs and it uses ~85kWh or £12. And costs £200 odd for the LEDs.

So CFLs take less than 6 months to pay for themselves. LEDs take 2.8years. That's still very much worthwhile, but if you can't wait 3 years to start saving, just do the CFL thing.

[langstroth2]

I know some here get a lot lower consumption, but for us we've been heading in the right direction since using the efergy meter and plug in meter to monitor daily load/check individual appliances. It's not affected life style (well I've had no significant complaints!). I'd second many of the above suggestions, many of which we've implemented.

I drew up a list ordered by KwH consumption (measured or estimated) and then started with the worst offenders - which in our case was an old freezer and kitchen lights (edited: not including the tumble drier, which we just avoid using most of the time).
Now the efergy meter gets used most at bedtime - if base load isn't at or below 90W something is on that shouldn't be (apart from the freezers being on occasionally).

Our yearly consumption has dropped by 1000kw from ~5,000KwH / yr 2008; to 4000 KwH for 2009 (based on elec meter readings). i.e 20% reduction 2009 compared with 2008. (11KwH / day. Baseload at night 90W approx). ~£116 a quarter

2 adults + 2 junior age children.

It's do-able.

[JamesGreen]

So, what is the best meter?
I have two low-cost meters (made you know where) and even though they display a value for power factor, they fail to take it into account.
In fact on devices with reactive loads they are miles out.
The same thing can be said for many clip-on CT types.

Has anyone done any tests of Power Meter versus reality (with various type loads) ?
I'm not excpecting lectric meter standards but the two i have are rubbish for anything except nearly-puirely resistive loads.

I know you tend to 'get what you pay for'  but are there any decent low-cost ones around?
("decent" = failry accurate for 95% of loads, as opposed to cheapos from Ebay  )

I was hoping to get some fairly accurate figures , and not just being 'made aware' of my consumption.
TIA.

[JamesGreen]

I borrowed a calibrated Energy/Power meter and conclude that of the five makes I tested some cheapoes are quite good, but some are as much use as a Chocolate Fireguard. I was surpised and very disappointed.

Sure, they make you  aware .
And it seems that everyone takes those digital figures as accurate. But they can be very deceptive.
One make I tried to measure my PC consumption was 40% in error (and I had two of this type, both were awful).
I realise the basic reason why they are in error.

And, as for those purely clip-on types. They can be miles out for much the same reason.

Just be aware. Don't base your energy usage/costs on cheapo (or purely clip-on) Energy Meters unless tested - you may be surprised.

[Rooster]

Don't keep us in suspense then ..... which ones tested as good ..... and which ones were miles out?

Name and shame them!

 

[JamesGreen]

A couple from Maplin and a low-cost supermarket were quite good, they made good use of PF and were good at low wattages if you wanted to check <15watt loads (apparent power).

The worst were two models from CPC type PL10053. Fine for purely resistive loads like a basic electric fire, but completely miles out for anything with a transformer, or sw/mode supply . e.g. PC.
In fact when testing a low-ish power switched-mode mains-DC test supply, the PL10053 indicated 10W and the true value (according to a £1000 meter) was 1 Watt. That was confirmed by another meter which used an STPM01 Energy chip.
Two PL10053s were tested, both showed huge errors on reactive loads e.g. your PC.

I was surpised about 2 things.
1. That no-one had replied to my first post ...
2. Just how far out some of these things are.

There have been some very disparaging comments about clip-ons in other places... what do you expect - no PF correction.

It's about time some proper measurements were done so that people can see what is good or bad or at least know the limitations.
It can be very deceptive and the temptation to believe a magic digital display is fully understandable. Computer says...

[pb]

The worst were two models from CPC type PL10053. Fine for purely resistive loads like a basic electric fire, but completely miles out for anything with a transformer, or sw/mode supply . e.g. PC.
In fact when testing a low-ish power switched-mode mains-DC test supply, the PL10053 indicated 10W and the true value (according to a £1000 meter) was 1 Watt. That was confirmed by another meter which used an STPM01 Energy chip.
Two PL10053s were tested, both showed huge errors on reactive loads e.g. your PC.

Are you saying that the PL10053 just doesn't make any attempt to measure power factor, or that it does try to measure it but the results are wrong?

[JamesGreen]

From my all too brief tests, it would appear the latter. The device can show the PF but didn't appear to compensate - unless, of course, both of my plug-ins were faulty. I've given them both to my brother-in-law now so can't do any more tests.


Also look at this... about 3/4 of the way down under the heading " Energy Meter reliability "
http://www.frequencycast.co.uk/energymeters.html

It seems 'awareness' is more important than even approx. accuracy.