Energy consumption reduction opinions sought.

[JDT2Q]

Hi group,

Today I completed the monthly on line meter readings submission for my energy supplier and was presented with a bill for about £450 for the past quarter. I was amassed. The bill is paid by monthly direct debit and it just about flatted the accumulated credit in our account since our last bill. No doubt the supplier will increase my approx £110 per month direct debit as we are not out of the winter period yet. The bill is for both gas and electricity.

We switched suppliers a couple of years ago using Uswitch so we are not with the historical suppliers for the area. I will be comparing prices again soon once the playing field is level.

Our house is a semi dormer bungalow ( not a very big one ) in the North West. We have cavity wall insulation, loft insulation, double glazing, combi boiler ( 2 yrs old ), and programmable room stat. Most of our light fittings are CFL's. We have a dishwasher, tumble drier and electric oven with gas hob.

It's difficult to see how we could economise more than we do on the high consumption appliances - especially gas.

I am starting to look at the electrical consumption of low consumption items. For example, the door bell transformer is lowish consumption but powered up

24/7/365 and it is an old style one and not a Switched Mode Power Supply. I know from my electronic engineering training that the 'old style' transformers are relatively inefficient compared to SMPS - iron losses and such.

This is very much a 'started today' project but on basic calculations if the bell transformer consumed 100mA ( not yet measured it so I may be way out ) and it's powered up 8736 hrs per year ( all year ) and my supplier charges

9p per kilowatt hour ( excl VAT ) then it's costing us £18.86 per year just for the bell transformer. Our alarm system also has a 'traditional' PSU and is powered up all year. That is likely to consume more than the bell transformer as equipment IS being powered 24/7 so, on assumed consumption figures ( mA ), we are now up to more than £37 per year wasted, much of it on iron loss. I know that most modern electronic devices/appliances use SMPU power supplies.

I'm thinking of swapping power supplies for these 'traditional' items to SMPU's - easy for the door bell, not as easy for the alarm system.

We have several modern devices powered up 24/7/365, cable modem, router, network switch and the usual videos, TVs etc. I am thinking of putting these on electronic timeswitches to power them down between, say, 01.00 am to 10.00 am.

I know the real killers are tumble driers, cookers, washing machines etc as regards electricity consumption.

Basically I'm looking for any other ideas to reduce our consumption based on the info I have given.

All of the low consumption items take little power individually but added together and viewed over 12 months powered up time, savings with possible power unit conversion could be worth while.

BTW I have loads of redundant SMPS units to use so no capital outlay.

Time to get out my AC current meter and calculate just what each is costing us - then add it up.

Any suggestions ??

[OG]

Can you tell how the costs split between gas and electricity ? We find we spend about 2x as much on gas as electricity, so although it's always worth trimming back the electric bills as much as you can, the bigger savings may be made by concentrating on the heating (presumably gas CH).

If you've got any little used rooms, turn off the rads and keep the doors shut. Keep living room doors shut to reduce draughts and keep the heat where it's needed. etc etc. Turn the thermostats down by 1 or 2 degrees. Switch the heating off 30 minutes earlier in the morning and afternoon.

That sort of thing.

[Bob Eager]

Be aware that Uswitch are good at hiding some companies if they don't get a kickback.

Good idea...although I suspect it's less than you'd think.

Video and TV should just be turned off when not in use. Can leave something on if you need to record - a time switch just makes it fiddly then.

Tumble drier particularly - don't know the economics of gas ones, given initial costs.

I found our washing machine consumes nearly 10 watts on 'standby' - that is, when it's finished the wash but not been turned off at the wall.

I've built some low consumption PCs since some have to be on all the time. The firewall (a FreeBSD machine) is under 20 watts.

[meow2222]

the tumble dryer's an easy one.

I am starting to look at the electrical consumption of low consumption > items.

small ones are, yes.

3w would be more realistic.

exactly, and those are tacklable. Tumble dryer: as described in the wiki link Foods: use lids on pans, turning the gas all the way down Veg: nuke rather than boil, add 1tb of butter & water first, they taste better too. Oven: put foods to be cooked in without preheating the oven. The foods ready a couple of minutes sooner, and you lose 5 minutes of on time. If you use a pc as a router, make it an old laptop

right... should be esy to replace the wallwarts then. But I'd check the smpsus dont use just as much. Dont assume theyre more efficient, but they will usually eat less when on standby.

yes - measure everything, the power consumption. You need an rms reading meter, a standard ammeter wont be much use.

NT

[Steve]

You don't say how much is actually electric of that bill, I would expect gas to be the majority, but assuming you are only targeting the electric I would start by grabbing a whole house energy meter (owl, eco-eye, efergy etc). They are not 100% accurate, they don't need to be, they are only a quick method of targeting whats taking the power.

Also re-switch the computer and tv gear onto separate gang plugs where needed so that one whole set can turn off with one switch and leave on the sky+/recorder as needed. That alone saved me £10 per month.

Your likely to find that things like the bell use almost nothing, and the bigger items like the fridge/freezer that are using the most, but you may find others that catch you out. The meter helps find what the usage is, but is also helpful in enforcing a habit of switching things off, or using things less (like a kettle etc)

Steve

[Andy Cap]

TRVs on radiators are very effective and how you program your roomstat. Having it lower during the day when you are either out or relatively active and much lower during the night. Then of course, only heating the water when it's required. These changes would make a substantial difference, if not already done.

[Huge]

I'm using an "intelligent" power strip, which switches off all the ancillary kit when the PC is powered off. A little like this kind of thing;

I've built some low consumption PCs since some have to be on all the

I run Softwall on an old Dell Optiplex for my firewall. That gets switched on and off by the "intelligent" power switch. It seems to have survived so far. :o)

All three PCs (mine, my wifes and the f/w), use less power between them than the Sun I have just retired ...

Actually, I have a problem with the switch. My wife and my PCs are both plugged into the sense port, mine directly and my wife's via a 10M mains extension. It appears that my wife's PC (an HP Pavilion) doesn't draw enough current to reliably switch the power strip, in that it switches off once the machine has initially powered up... Obviously I need to experiment with this (I don't want to - there's a rat's nest of wiring) but could it be that the extension lead is somehow confusing the "intelligent" switch?

[Mark]

I always switch the CH off when I am out.

[Dave Liquorice]

Do the maths on P=3DVA, 24W of losses in a transformer how hot does this= thing run!

You can probably disconnect the transformer and patch batteries in instead. The bell only takes power when the push is pressed, batteries last for donkeys years.

That's a good ball park price these days.

Might be worth it for the alarm but feel the transformer, I really don't= think there will be much loss in it to be honest.

All those things taking power, the modem/router/switch are probably 30W =

all together add in the TV's Videos and other set top boxes and you migh= t be looking at 2 units/day or =A360/year.

Tumble dryer as they take quite a bit for a long time. Other things may = be high loads but don't take high power for long. Fridges and freezers consume quite a bit are they A or A+ rated appliances?

[The Natural Philosopher]

Only a comment from David Mackay's book 'without hot air'

'A little of a little makes a little'

Dont waste your time trying to shave 5% off 5% of your costs.

Better to go for 2% of 50%..

[Andy Cap]

I might do that, or at least set it lower, if I wasn't retired, but I'm in and out all day and like to come back to a relatively cosy house. Worth considering though, according to personal circumstances.

[Andrew Gabriel]

I'm assuming your 2 year old combi is a condensing one? To make that most efficient, turn down the heating water temperature. Ideally, you want it low enough that the room stat almost, but never quite has to click off, although that's an ideal you might struggle to achieve in practice. That point will vary with outside temperature, and you'll need to boost it back up temporarily when getting house warmed up from cold. (This is what a weather compensation control system will do for you automatically.)

When you are out of the house for periods of time, are you still heating it? (Having had remote control over my heating for nearly 10 years now, I'm somewhat amazed this still isn't a standard feature in all new heating systems.)

You will be way out. It's probably giving off something like 1W. Using a ballbark figure of £1/W/year, that's going to cost you about £1.

Some SMPSU's are highly efficient (e.g. most recent mobile phone ones, which just aren't worth switching off anymore). However, many are not, and without data on the efficiency, you might not gain anything. I buy SMPSU's quite often for projects I build, and mostly I just have go by trial and error to find efficient ones, and discard the less efficient ones I happen to come by.

Modern TV's, videos, etc which are made for multiple countries will be very low power on standby, as many of those countries now require that. Things that are made only for use in the UK, such as set top boxes, cable modems, etc can be very poor, as we don't have any such requirements. That can also apply to separate UK-specific wall-wart power supplies for things like routers/switches. (E.g. Netgear products in the UK seem to come with horribly inefficient wall-wart supplies, but the identical product bought elsewhere can be obtained with an efficient SMPSU.)

A number of the anciliary devices which come with their own wall warts, I instead power from the PC's power supply (drawn off from a spare disk drive power connector). You can only safely do this for items which are completely isolated (e.g. ethernet switch, WiFi access point, etc) or devices which you know share a common

0V ground reference with the PC. Don't do it with anything which interfaces to a phone/ADSL/cable line. You'll also need to select items which can run from 5VDC or 12VDC.

Washing machines aren't, unless you do frequent hot washes (which you shouldn't be). Tumble driers and electric hobs can be.

They may not necessarily be particularly efficient.

Get one of the plug-in power meters. There are several around now for less than £10. Measuring current draw alone won't tell you much with most modern kit.

[Tim Downie]

How much loft insulation? Depending on how long ago it was done your loft could be well below current recommendations. In terms of value for money, it's a good place to start if it needs topping up.

Tim

[David Hansen]

On Wed, 04 Feb 2009 11:25:11 +0000 someone who may be Andy Cap wrote this:-

Thermal store. Come in, press button, radiators warm in less than a minute. Assuming it is warmer inside then by the time one has adjusted to inside conditions the house is being warmed.

[Big Les Wade]

Andy Cap posted

You can get fancy electronic (or even electromechanical) room thermostats where you can set a temperature profile to vary during the day.

I'm not sure how easy they are to use though. Probably not very :/

[dennis]

Low water content system.. push button wait 90 sec and heating is hot.

*No* thermal store used so less energy wasted.

[Andy Cap]

Yep. Got that. Not quite the same as turning it off though.

The problem with hi-tech solutions, is cost/savings. If you're going to be dead before pay-back time, I'd rather spend the money on pleasurable things ! ;-)

[Andrew Gabriel]

You'll get the same with most combi's, as the heating side ends up having to be way over-spec'ed for house in order to provide any hot water flow.

[David Hansen]

On 04 Feb 2009 12:50:28 GMT someone who may be [e-mail] (Andrew Gabriel) wrote this:-

Not quite as fast, but certainly a lot faster than a "traditional" setup.

[Mike Clarke]

But bear in mind that the cheap ones will probably be highly inaccurate when measuring light loads. So they won't give realistic results for measuring the power of things on stand by.