We use solar energy,  sunlight, for most of our domestic lighting needs and there is not much more we can do to increase this significantly. Perhaps some new or larger window openings or light tubes to bring daylight into internal landings and bathrooms.

For the hours of insufficient daylight, mankind has always sought artificial light: fire, candles, gas electricity. Cheap electric lighting has meant that our houses are more brightly lit than ever before. The search for more economical lighting has resulted in the development of low energy lamps, which are now readily available and widely used and are replacing tungsten lamps that have been with us for a hundred years. But many homeowners have installed large numbers of low voltage halogen downlighters in the last few years. They each consume less energy, but we usually have more of them-cancelling out any saving. New low energy halogen lamps have been developed that use up to 40 %less energy. High efficiency LED's (light emitting diodes) which use tiny amounts of electricity to produce the same amount of light are now available to substitute for halogen.

Perhaps the uniformly high and harsh levels of light we have become used to are a thing of the past and we can save energy and money by getting used to lower levels of lighting in our homes and using light more selectively for particular tasks.

ENERGY EFFICIENT LIGHTING

Contribution by David Madams, Director, COMMERCIAL LAMP SUPPLIES Ltd

With the recent increases in electricity prices the focus has been on low energy and energy efficient lighting.
If you haven't changed your domestic lighting over to low energy you are wasting a lot of money.
Each one you change will save you about £14.00 per year on your electricity bill.

LOW ENERGY LIGHTING EXPLAINED

Ok, so it may only be a small bit of explanation but here goes!

Your ‘normal' lightbulb (an incandescent lamp) has a filament inside that is heated up with electricity until it glows and this creates the light. It works well but isn't efficient as it wastes a lot of its energy as heat.
The low voltage halogen spotlights or capsule lamps are a variation on that theme. They are more efficient but not too much (Remember the fact that they are 12 volt does not make them low energy - it is the wattage that counts).The usual low energy lamp is called a Compact Fluorescent Lamp (CFL) and is based on a fluorescent tube (the ones in most offices). They produce light by exciting mercury in a vapour form which in turn emits light (thats a simple version obviously!) The coating on the tube dictates the spectrum of light produced by the lamp. Flourescent lights are much more efficient than filament lights and there are many more colour variations available.A handy rule of thumb when buying low energy lamps is to multiply the wattage of the low energy lamp by 4. That will give you the approximate equivalent in ‘normal' lightbulb wattage.LED's are coming along. They are quite possibly the future of lighting. They have a huge lifespan and consume very little power. The usual problem with LEDs is they are quite 'spotty' and don't really do well as ambient lighting. LEDs also used to give out a very cold blue light but that problem is being addressed now so is much less of an issue. With LED technology it is definitely a case of ‘watch this space'.....

COMPARISONS WITH INCANDESCENT LAMPS

1. COMPACT FLUORESCENT LAMPS (CFL's)

Lifespan
Modern CFLs typically have a life span of between 6,000 and 15,000 hours (though total light output generally drops during long term use), whereas incandescent lamps are usually manufactured to have a life span of 750 hours or 1000 hours. These lifetimes are quoted according to IEC60969, which specifies that "life to 50% of failures shall be not less than value declared by the manufacturer." Special-purpose incandescent lamps used for projectors and photographic lighting have shorter lifespans. The lifetime of any lamp depends on many factors including manufacturing defects, exposure to voltage spikes, mechanical shock, frequency of cycling on and off and ambient operating temperature, among other factors.

Energy Consumption                                                                                                                         For a given light output, CFLs use between one-fifth and one-quarter of the power of an equivalent incandescent lamp, thereby saving significant amounts of energy in use and reducing the need for electrical generation. However, the energy required to manufacture these lamps is higher than incandescent lamps, and as a result the total lifetime energy use (from manufacture to disposal) compared to other forms of lighting is less than the simple comparison of electricity consumption implies. For industrialized countries, lighting makes up about one fifth of electricity consumption, so there are potentially significant benefits.
Incandescent lamps are less efficient than CFLs because incandescent lamps convert approximately 90% of the energy they consume into heat (compared to 30% for a CFL). Lighting accounted for approximately 9% of household electricity usage in the United States in 2001. If widespread use of CFLs could save three-quarters to four-fifths of this, it would amount to a total energy saving of about 7% from household usage.
Energy Efficiency
In order to compare the actual energy efficiency of CFLs with various other lamp technologies such as incandescent, LED and halogen, factors to compare include luminous efficacy, the subjective usefulness of different frequencies of light, the distribution of light over imaginary 360° spheres around the lamps and others. In round figures, typical incandescent lamps are around 2% efficient and domestic CFLs are currently 7%-8% efficient in usage (life cycle comparisons are necessarily more complex).

Cost
In addition to the above savings on energy costs, CFLs' average life is between 8 and 15 times that of incandescents. While the purchase price of a CFL is typically 3 to 10 times greater than that of an equivalent incandescent lamp, the extended lifetime and lower energy use will compensate for the higher initial cost in many applications. CFLs will fail prematurely if overheated and are not suitable for enclosed or non ventilated light fixtures, including most recessed lighting fixtures. Adapting fixtures or installing new ones for CFLs will raise the initial installation cost when required.

2. LOW VOLTAGE DOWNLIGHTERS

Low voltages spots and down lighters are not a low energy product!
It has become fashionable to use low voltage down lighters in kitchens and bathrooms, but they do use a lot of energy. Eight 50w down lighters will burn 400 watts per hour. We can't do to much about it but the new Philips Master line Energy Saver more efficient LVs are a good start. They produce as much light as the 50 watts but only burn 30 watts.You can still dim them and they last much longer than ordinary ones.
Over their life they will pay for themselves many times over.The normal 50 watt LV has an average life of 1000hrs; the ES energy saving LV has an average life of 5000hrs! so 4 less lamps to buy and it uses only 30 watts of electricity to produce the same amount of light, so although it costs more per lamp originally the extra life and the reduced power consumption make if cheaper to use! It is the only real low energy alternative for the low voltage systems, because although they are low voltage, a 50 watt lamp still uses 50 watts of electricity! So what this lamp does, as well as lasting 5 times as long as the normal ones, it uses 30 watts to produce 50 watts of light! You will only change one fifth as many lamps as they will last longer and save energy for you the whole time!

3. LEDs (LIGHT EMITTING DIODES)

There are LED lamps available but as yet they do not produce anywhere near a 50 watt dichroic's light output and are best used in ambient lighting, ie for effect not for working areas.

4. LOW ENERGY SECURITY LIGHTS
We think these are a real breakthrough we finally have a genuine low energy replacement security light bulb that will transform your security lighting into an efficient low energy system without the need to replace your light fittings.These units will fit into any normal tungsten halogen security light fitting which uses the 118 mm tube at present, this is the normal length one (that's about 4and a half inches) there a literally millions of them in use in the UK. There are smaller ones but they are very short at 75 mm approx 3 inches so it is very obvious. The larger ones are less common and much much bigger so you won't mistake them.The beauty of these units is that all the control gear is integral with the lamp, you can fit them in seconds, no wiring necessary they fit exactly the same as the tungsten halogen tubes.

The benefits are.
1. They start instantly, just as fast as the tungsten halogen bulbs.
2. The have a life of 8000 hours which is about 16 times as long as the filament lamps they replace.
3. They give a crisp white light which is perfect for the purpose.
4. They only burn 24 watts, the lowest power conventional filament lamp is 150 watts so the saving is massive they use only 20% of the power to do the same job,

We estimate they are a direct equivalent to 150 to 200 watts in light output. we have installed them where we did use 300 and 500 watt lamps and they are perfectly acceptable, not as bright obviously, but every bit as good in terms of a deterrent to intruders or just to see where you are going.

If half the people in the country who have security lighting changes to these low energy lamps them it would make a massive difference to the nation's energy consumption.

If you want to be green here is a great way to start and you'll save money as well.

Other uses we can think of are Church Lighting which is often a problem, a long life low energy solution with a low capital cost could be a very nice answer to your lighting problems.

TRANSFORMERS

Modern transformers are electronic and are no longer big heavy things, they are also very reliable and they all work with dimmers.

Most are small enought to fit up through a downlighter fitting making installation very easy. The 60 watts are matchbox size.

To work out what size you need count how many bulbs you have or want, choose a wattage and multiply that by the number of bulbs, this will give you the size of transformer you need.EXAMPLE: 6 downligters each with 35watt spotlight = 210 watts, we would need either 2 x105 va transformer each running three fittings or one 210 transformer if you prefer.

For more details contact:

David Madams, Director,

COMMERCIAL LAMP SUPPLIES Ltd

Quither Down Business Park, Hayedown, Tavistock. PL19 0NN

Tel:  01822 860110, Fax: 01822 860 427 and Email: sales@commercial-lamps.co.uk

To visit their site click here:  www.commercial-lamps.co.uk