Energy saving lightbulbs

Energy Saving Lightbulbs

In most households lighting accounts for between 5% and 10% of the typical electricity bill. With energy saving bulbs this can be cut to around 1.5% to 2.5%, so it makes financial as well as environmental sense to replace ordinary lightbulbs with more efficient ones.

Compact Fluorescent Lamps

A compact fluorescent lamp (CFL), also known as a compact fluorescent light bulb or an energy saving lightbulb is more energy-efficient than an ordinary lightbulb because of the different method it uses to produce light. Ordinary lightbulbs (also known as incandescent bulbs) create light by heating a filament inside the bulb; the heat makes the filament white-hot, producing the light that you see. A lot of the energy used to create the heat that lights an incandescent bulb is wasted. A CFL, on the other hand, contains a gas that produces invisible ultraviolet light (UV) when the gas is excited by electricity. The UV light hits the white phosphor coating inside the fluorescent bulb and the coating changes it into light you can see. Because fluorescent bulbs don't use heat to create light they are far more energy-efficient than incandescent bulbs.

The first CFLs flickered when they were turned on because it took a few seconds to produce enough electricity to excite the gas inside the bulb. With newer technology there is now no significant flicker when the bulb is turned on (less than 1 second). However, the bulbs do require a short warm-up period before they reach full brightness, which is why they may appear dim when first turned on.

As the CFL is more efficient than an ordinary bulb a lower wattage CFL will provide the same amount of light as a higher rated ordinary bulb, resulting in lower power consumption for the same amount of light:

CFL rating	Ordinary lightbulb equivalent
9W	40W
11W	60W
20W	100W

Some of the latest CFLs have an expected life of 15000 hours, compared to an average of 1000 hours for an ordinary lightbulb. This results in a large saving during the life time of the CFL.

For a 20W CFL: 20W x 15000 hours = 300kWh
For a 100W bulb: 100W x 15000 hours = 1500kWh

A difference of 1200kWh. At current prices of 11p per kWh this gives a saving of �132!

See other CFL savings

The main shapes of CFL are shown below. The "stick" type are the easiest to produce, and therefore the cheapest. The "spiral" is the most expensive to produce, but the most compact. There are various other shapes available eg. candle, these are made by putting a glass shell around a stick or spiral CFL.


Stick CFL	Spiral CFL	Reflector CFL

Availability in Stafford

Lektrix, 29 Crabbery Street, Stafford, stock a wide range of manufacturers, including Kosnic, Helix, Omicron and Osram. They also stock LED halogen replacements.

Wardstaff Electric, 3 Bridge St, Stafford have a small selection.

All the main supermarkets have some stock. Wilkinsons, Woolworths, Asda and Tesco all stock GE. Morrisions have Philips. Sainsburys have Osram.

Sainsburys have a "buy 2 and get �2.99 off" promotion on at the moment that means that you can get 2 Osram 15000 hour bulbs for �1.39. This appears to be the cheapest availability.

The cheapest spirals are at Asda for �1.68 (Spirals are more expensive because the tube is shaped by hand).

Note that you need special CFLs for use with dimmer switches. The standard ones flicker horribly when dimmed. Currently nowhere in Stafford seems to stock these.

LED halogen replacements

These contain 21 LEDs contained within a single bulb. They use approx 1.5W instead of the halogen bulbs 20W. Life of these is 30000 hours instead of the normal halogen bulbs 5000 hours. Cost is around �6.00.

These are a direct replacement for mains halogen lamps. Unfortunately fittings that use a transformer to run at 12 volts are not as easy to replace as just replacing the bulb results in a high level of flicker. Lektrix can supply a fitting that allows by-passing of the transformer.