Savings with LED bulbs?

[wowfudge]

How much could you actually save by changing to LED bulbs? DP sent me a link to a Guardian article on the subject and I'm wondering what the actual savings are?

We've been replacing bulbs with LED ones as they go, but are now thinking of replacing all the incandescent and halogen ones around the house. For example, in our bedroom there are 7 candle bulbs - the main light has 3.

LEDs use about 1/6 of the electricity that an equivalent incandescent would, and about 1/4 of the equivalent halogen. How much you will save depends on how long you have a light on. I pay about 14p/kWh for my electricitiy, so a 100W incandescent bulb costs me 1.4p/h to run. An equivlent (18W) LED would cost 0.25p/h. The LED bulb might cost me about £7 in a shop (but probably less online), so I would need to run that bulb for about 600 hours to recoup the outlay. LEDs are typically rated as lasting around 50,000 hours.

Example:
A 100W bulb run for 2hrs per day for a year will use 73kWh (2 0.1 365) at a cost of £10.22 (73 * .14).
An 18W LED will use 13kWh (2 .018 365) at a cost of £1.82 (13 * .14).
If the LED cost £7, it would take 10 months to pay for itself.

We changed when we found we could buy a GU10 LED for a couple of quid online. If we had been paying high street prices the payback period would have been too long given that most of the lights aren't on that much.

Unfortunately, for us, any reduction in running cost of the replacement LED GU10s is negated by the atrocious high pitched whine. An unfailing migraine inducer.

We don't have that issue thankfully, but we do have a lot of lightbulbs, including some halogens.

Thereisnosuchthing - thank you. Very helpful.

Rumboogie was that with them on a dimmer switch?