In recent years there has been a massive change in the designs of light bulbs. UK and EU laws have outlawed traditional filament bulbs because they are so inefficient. Virtually every bulb in the shops is now a CFL bulb.
CFL Light Bulbs UK
If you are replacing a filament bulb for the first time you will be amazed at the range of bulbs you have to choose from.
There are some that look like a bent around, miniature fluorescent tube. These are usually the cheapest. Ikea sell them for £1 each. Asda prices vary, but they are usually good. These same bulbs in Tesco can cost £6 or even £9 in small electrical shops. They are all the same, so just buy the cheapest.
Other compact fluorescent bulbs (CFL bulbs) are available that have a frosted glass diffuser over the coiled fluorescent tube. These cost more. They are also larger than a standard bulb and often project beyond a lampshade in small table lamps. The diffuser is not necessary. The earliest CFL bulbs had this design and some are very slow to warm up and reach maximum brightness.
Other bulbs available in UK include candle, twisted candle and golf ball bulbs.
To make life even more complicated light bulbs come in the standard UK bayonet fitting and the US Edison screw fitting. There are also SES (Small Edison screw) and SBC (small bayonet cap) fittings.
Bulbs with the UK and EU bayonet cap are better than Edison screw bulbs. If you have a screw in light bulb it becomes hot and the soft metal at the end distorts. This is one of the electrical contacts in an Edison screw bulb and as it distorts you have to screw the bulb in further. Eventually the screw in bulb stops working. Bayonet cap bulbs last longer because you do not have to keep fiddling with it and screwing it in an extra quarter turn.
Always try to find lamps and light fittings that accept bayonet cap or small bayonet cap fittings in UK.
You can buy converters to convert a lamp from a US Edison Screw fitting to the standard European Bayonet Cap. These only cost about £2.50 and are well worthwhile given the greater cost of CFL bulbs. It is better to pay £1 for a BC bulb that will last eight years than £1 a year for ES bulbs that have died early.
Consumers are justifiably annoyed by the high prices of CFL bulbs in UK. Many are tempted by cheap US light bulbs available over the Internet. Light Bulbs, UK style, are 220v and light bulbs, US style, are 110v.
The two standards are incompatible. UK consumers are stuck with the high prices for bulbs in Britain. (The same applies for any electrical goods sold at half UK prices in US, they are incompatible unless there is a voltage selection switch like the ones found on electric shavers)
Halogen Light Bulbs UK
Spotlight bulbs have been improved in UK, and are now more efficient. Even a new improved efficiency halogen bulb uses four times the energy of a CFL spotlight, and forty times the energy that an LED spotlight bulb uses.
Spotlights are fashionable, but you will pay for your design choice with every electricity bill that arrives. If you have spotlights, you should experiment with the lower energy CFL and LED spotlight bulbs that are now sold by many UK retailers, or through Internet sites like Amazon.
Daylight Bulbs UK
Be careful that you specify a high enough wattage, the correct voltage and the correct fitting for your lamp.