Domestic Energy Efficient Lighting - Electricians Southampton

Lighting accounts for 8% of a typical household’s energy bills and cutting your lighting bill is one of the easiest ways to save energy and money in the home.

low energy lighting southamptonCablefrog Electrical are able to replace your traditional light bulbs with a compact fluorescent bulb of the same brightness saving you about £3 per year per bulb, or £55 over the life of the bulb. You can save even more by replacing a 50W halogen downlighter with a 6W LED, around £4 per year per LED, or £70 by the time you have to replace it.

Whether you rent or own your property, or live in a house, flat or bungalow, Cablefrog can help you save money simply by fitting new energy-saving lights. Most homes today use a mixture of standard light fittings and halogen downlighters. It is importnant to know that there are low-energy alternatives for both these types of light.

  • Compact fluorescents (CFLs) – these are what most people think of as an energy-efficient light bulb. A cost-effective option for most general lighting purposes, and now widely available.
  • LEDs – even more efficient, and the ideal replacement for halogen downlighters. More expensive than CFLs but save even more money in the long term.

Lighting myths

Q. Do energy-saving lightbulbs take a long time to light up? 

A. They used to but modern energy saving bulbs take little more than a few seconds to warm up to full brightness.

Q. Do traditional bulbs give a better quality of light?

A. The light quality of CFLs and LEDs does vary.  If you want a light that looks the same as a traditional bulb, buy a “warm white” or “soft white” bulb. A Colour Rendering Index (CRI) should be printed on the packaging, for a traditional level of light look for at least 0.8.

Q. Are halogen bulbs more efficient than traditional bulbs?

A. Halogen bulbs are slightly more efficient than traditional bulbs, and most domestic halogens have a lower power rating (typically 20W-50W for halogen bulbs compared with 40W-100W for traditional bulbs). However, rooms lit with halogen bulbs usually have more fittings than rooms lit with traditional bulbs or energy saving bulbs. So they will use more energy. To save much more energy, replace halogens with the new generation of LED lamps.

Q. Can I fit them with energy saving bulbs with dimmer switches?

A. At the moment a lot of energy-saving bulbs are not properly compatible with dimmer switch circuits. There are however a growing range of dimmable CFLs is emerging to address this problem. There are also energy-saving bulbs that can be used with ‘staged dimming’. This requires a special sort of dimmer with three separate settings – high, low and off.

Q. Is the government banning traditional incandescent bulbs?

A. The government, energy suppliers and many major UK retailers have lead a voluntary initiative to phase out incandescent light bulbs, where there is a suitable low energy replacement. The UK voluntary phase-out is now being followed up by legal restrictions on bulb sales across Europe, so in a way yes they are.

Q. Can I recycle my energy saving light bulbs?

A. Energy-saving light bulbs are part of the Waste Electrical and Electronic Equipment (WEEE) initiative which means retailers must provide information to the public on how they can be recycled.

Q. Is low energy lighting as bright as traditional lighting?

A.  it will be just as bright as the one you’re replacing if you buy the correct bulb.

Q. Do they take a long time to get up to full brightness?

A. All CFLs and other fluorescent tubes take some time to reach full brightness after they are switched on. However, some are much better than others. Cablefrog can reccommend the right light for your requirements.

LEDs reach full brightness just as quickly as old-fashioned bulbs. If you want instant full brightness everywhere in your house, then you could consider LEDs throughout. LEDs for standard light fittings are still expensive and not widely available, but prices are expected to come down.

Q. Do they still give off a harsh light?

A. When buying any low-energy light, you have a choice about the quality of light it will produce. This is mainly to do with the colour of the light – when we buy a white light bulb we don’t actually want pure white light, and we would be disappointed if that was what we got. It is important to pick the right type of light for you, Cablefrog can help you with this choice.

Q. Can you see these lights flicker?

A. No, you can’t. Unless you’ve got a really ancient CFL that looks like an old jam jar, your CFL will be turning on and off about 50,000 times a second. This is about 1,000 times faster than the human eye can recognise.

Q. I’ve heard that if I use efficient lights, they will give out less heat and I will have to use my central heating more

A. This is actually true, but the effect is quite small. Most of the energy from lighting in UK homes does not contribute to space heating – it is either emitted at times when heat isn’t needed, or it goes straight out of the windows, or it leads to overheating and so doesn’t save fuel.

Light output

We often hear that people have bought a low-energy lightbulb and been disappointed when you got it home it just wasn’t that bright, even though it said “100 watt equivalent” on the packet. The problem is that “100 watt equivalent” doesn’t actually mean anything precise. The 100W figure is a measure of the electricity consumption of an old inefficient bulb, and is not a measure of brightness.

If you want to know how bright a light bulb really is you need a figure that measures its actual light output. Every new bulb you see in the shops will have its light output in Lumens clearly printed on the packet.

Matching lumens to Watts for GLS bulbs

Lumens GLS equivalent Where to use it
1,200 to 1,300 100W Usually the brightest bulbs in the house, single light fittings for lighting the whole room.
650 to 700 60W Wherever a less bright bulb will do, e.g. smaller rooms, rooms with more than one fitting.
350 to 400 40W Individual reading lamps, fittings that take more than one bulb.
200 to 225 25W Usually used to give ambient effect only, or to light cupboards etc.

Matching lumens to Watts for halogen downlighters

downlights kitchen southamptonWhen it comes to replacing halogen downlighters with LEDs, the numbers are slightly different. Halogens are often fitted in larger numbers giving off far more light than is actually needed. This means that an LED may be able to replace a halogen even if its output in Lumens is significantly lower.

Lumens Halogen equivalent Where to use it
300+ 50W If you currently have a few 50W halogens and you want to keep the same brightness.
200+ 35W If you currently have 35W halogens, or lots of 50W and you could manage with less light output
100+ 20W Usually for local lighting such as display cabinets, rather than general lighting.
less than 100 Not usually useful.


Everyone has their own preference on light colour and brightness and this various depnding on position and use of light. The sun gives out white light, and that is the sort of light we’re used to living in much of the time. But old fashioned light bulbs give out a much yellower light. Most low energy bulbs are designed to copy old fashioned bulbs to some extent, and are usually described as “warm white” or “soft white”. This will usually be the preferred option for general household use. Bulbs that are sold as “cool white” or “pure white” are likely to look less attractive in the home, but may be appropriate for workplace lamps and offices where clear vision is required.

Colour rendering

This is slightly different from colour. Two light bulbs can both give out white light, but certain colours will not show up well when illuminated by the first bulb, while they look fine under the second bulb. This means the first bulb has a lower colour rendering index (CRI).

color_rendering_index southampton

Traditional bulbs have a CRI of 100. A good CFL will have a CRI of 80 or more, which is good enough for normal domestic use. Most LEDs have a CRI of 90 or more, so are usually fine. However, if you buy bulbs with a CRI of less than 80 there is a risk that the quality of light in your home will look a bit odd.

If you have any questions regarding lighting your home of energy efficient lighting please contact Click here to contact your local electrician in Southampton.