Efficient Home Lighting – CFL versus Incandescent

This month the humble lightbulb has been put in the (energy saving) spotlight as the EU’s phase out of the traditional incandescent begins, and so it seems like a good time to review some of the alternatives on the market and where you can find them.

Incandescant bulbs – “The Heater that emits a bit of light”
These are the ‘old’ school bulbs that are being phased out due to new EU regulations on performance requirements of energy-using products.
Only around 5-10% of the energy used by these bulbs actually goes to generating any light, with the rest being wasted as heat so it’s clear why it’s time for the newer CFL technology to take their place.

LED Lamps
LED lamps are typically made by grouping a number of individual LEDs together and are currently one of the most efficient lighting technologies. LEDs come in a range of colours, allowing for coloured lighting solutions, and even packages where the mix of colour can be controlled.
As LED lamps remain a relatively new addition to the residential lighting market the initial costs are high. So, in purely monetary terms, LED lamps seem to be not quite cost effective just yet.
However, the cost is bound to fall as more get manufactured and so are definitely ones to watch in the future.

Energy Saving bulbs
Compact fluorescent lamps (CFLs) are the most common energy saving lightbulbs and are similar to the fluorescent tubes traditionally installed in commercial buildings.

There have been criticisms that energy saving lightbulbs take too long to turn on, or can’t be used with dimmers but most of these isses have been resolved in newer versions.
There is some evidence that equivalent rated bulbs aren’t quite as bright as their traditional counterparts, but I’ve found the light from CFLs to be perfectly good and in my opinion the reduced energy use more than makes up for any other limitations.

Importantly, while traditional incandescant bulbs can be disposed of in your household rubbish, energy saving bulbs (CFL’s) contain small amounts of mercury and so need to be recycled properly (although the longer lifespan of these bulbs mean it shouldn’t be necessary too often) – For advice on where to dispose of energy saving lightbulbs, see the Recolight guidance here.

So what’s the best option?
A very quick cost comparison of a typical year of operation shows that replacing 60W incandescants with 11W energy saving bulbs is over 5 times more cost effective – obviously there are some big assumptions here, such as ignoring the heating effect that a lot of old bulbs might give, but even replacing each 60W with two energy saving bulbs still looks better for your pocket and the environment (if disposed of correctly!)

	CFL	Incandescent
Power Used (Watts) (Light output might not be exactly equal, but these have been sufficient for my needs)	11W	60W
Lifetime (Hours) (Average lifetime as from the EnergyStar website)	10500	875
Cost each (Based on prices from British Gas and Staples)	£1.49	£0.75
Hours in operation (Assuming 6hrs / day for a year)	2190	2190
Bulbs Needed	0.2	2.5
Total Cost of Bulbs	£0.31	£1.87
Energy Used (kwH)	24.1	131.4
Energy Tariff (£ per kWh) (This is the average tariff prce as used by the Energy Saving Trust)	0.1296	0.1296
Energy Cost	£3.12	£17.03
Total cost over year	£3.43	£18.90
Where to buy?	CFLs are widely available for example from British Gas, Lightbulbs direct or most hardware stores. For dimmable versions, check Ryness.co.uk.	Just in the name of being fair, Incandescent bulbs can still be purchased from Staples, but hopefully after reading you might consider the alternative option!
Other considerations	Contain small amounts of mercury – needs proper disposal. Price continuing to fall	Can be disposed of easily, but price likely to increase now phase-out begins