There is no doubt that LEDs are the future of lighting. They are now being used in everything from car headlights to street signs. LEDs are green lighting solutions requiring less electrical consumption than bulb based lighting systems to deliver the equivalent power.

There are 3 main reasons why end users are move from bulb based CCTV lighting systems to 'greener' LED based lighting systems:

- Technical advances in LED technology now make LED illumination possible.

- LED illuminators provide increased security on site.

- LED illuminators deliver huge cost savings

1: Technical advances in LED technology

LEDs are being deployed in more and more applications. They are unquestionably the future of lighting and offer longer life and greater durability than bulbs. Of course, they are also far more efficient than bulbs, using less electrical energy. This makes LEDs a true 'Green' lighting system.

To understand why LEDs are the future of CCTV lighting it is important to know the advantages and disadvantages of the different forms of CCTV lighting.

The different sources of light and their suitability for CCTV:

Incandescent Lamps

For CCTV purposes, bulb life is limited and they are very inefficient. They are generally expensive to run (typically 200 or 500 watts) and expensive to maintain (upto 3 bulb changes per year). End users are increasingly moving away from using halogen based lighting products in favour of longer life LEDs.

Incandescent bulbs were the first bulbs developed and are highly inefficient, wasting 90% of input energy as heat. Their heat output is such that they are extremely hot to touch and can heat surrounding objects in close proximity.

Halogen bulbs provide a minimal increase in efficiency and still waste as much as 85% of input energy as heat. Halogen bulbs are smaller and higher pressure than incandescent bulbs causing halogen bulbs to have an extremely hot surface hazardous to the touch. Bringing the bulb into contact with cold surfaces such as residue for fingerprints, particularly sodium, may cause bulb failure.

Fluorescent Lamps

Their use for CCTV purposes is limited due to the perceived "beating" effect when used with a CCTV camera. They are generally low power and designed mainly for internal fitting. As they have a large diffused source the light output is difficult to focus and control.

Fluorescent bulbs are much more efficient than incandescent bulbs, operating at approximately 40% efficiency. Only 60% of the input energy is wasted as heat so fluorescent lamps run much cooler than incandescent lamps and can provide equivalent power from much lower electrical input. For this reason, and the fact that fluorescent lamps tend to last 10 - 20 times as long as an incandescent bulb, they are commonly used in domestic homes as long life bulbs.

However, fluorescent lamps product a flicker imperceptible to the human eye but visible to cameras as a "beat" effect making fluorescent illumination unsuitable for video surveillance. Fluorescent lamps also contain the hazardous material mercury.

HID Lamps

HID lamps could be used in CCTV. They are efficient, provide good colour rendition and are long life - up to 12,000 hours. However, they suffer from a slow start (2-3mins) and cannot be turned on immediately after being turned off.

High intensity discharge lamps are 60-80% efficient and compared to incandescent and fluorescent lamps provide much more light from a smaller package. HID forms include low pressure sodium (unsuitable for CCTV due to its yellow tinge), high pressure sodium (which is most acceptable but produces worse colour rendition than Metal Halide) and Metal Halide. Metal Halide HID bulbs provide a natural, cool clear White-Light with good colour discrimination. HID lamps are commonly used for street lighting and in car headlights.

LED's

LEDs are the fastest growing lighting solution for CCTV applications. They are extremely efficient offer unbeatable reliability. LEDs offer the lowest possible running costs (less than 100 watts for highest power units) with the longest operating life (up to 10 years).

Light emitting diodes (LEDs) are semiconductors that naturally emit a narrow band of light. They are a relatively new development in lighting but their usage is expanding rapidly on the back of clear technical advantages. LED's can be slightly more expensive to purchase but provide extremely long life up to 100,000 hours. In comparison fluorescent bulbs typically last 10,000 hours and incandescent bulbs 1,000. LED efficiency is typically 80-90% with the greatest efficiency coming from LEDs producing red light. Advantages of LEDs include extremely low electrical consumption, low operating temperatures and continuity of colour through the operating life of the LED. Unlike traditional bulbs LEDs are also highly durable, insensitive to vibration and their hard casing makes them difficult to break. They are also capable of emitting light at a given wavelength without the need for a filter and are quick start devices.

Power management and thermal management are important to ensure LEDs deliver expected performance.

Through hole LEDs are expensive to mount to PCBs and generally are not as robust as surface mount technology. Surface mount technology (SMT) LED's offer better thermal management and allow the LED's to be "driven" harder without compromising performance.

2: LED lighting provides higher levels of site-security

Well engineered, well powered, and most importantly, well controlled LED lighting allows for higher levels of security on site than traditional bulb based illuminators. LED lighting should provide in excess of 10 years hassle and maintenance free illumination. LED lights simply should not fail, and do not need regular replacement.

Older bulb technologies, whether halogen, metal halide or sodium, all require bulb changes, either when the bulb has blown, or at regular service intervals. Consider a large site such as a prison or military barracks. There may be 100 cameras monitoring the perimeter each fitted with an infra-red or white-light illuminator. If these are bulb illuminators that is 100 bulbs which require regular servicing and replacement with the use of a cherry picker and dedicated maintenance staff. Each time a bulb 'blows' rather than paying for a call out charge and the cost of a cherry picker (in addition to the cost of a replacement bulb), it is common to wait until a few bulbs have 'blown' in order to service multiple lamps in one visit. Obviously this leaves some of the site without adequate CCTV lighting and prone to attack by criminals.

LEDs provide high security, low risk lighting. LED illumination offers more security and more 'peace of mind' to end users, secure in the knowledge that whenever a crime occurs, the CCTV system will be fully operational.

3: LED lighting delivers huge cost savings

As previously covered, LEDs are far more efficient than bulb illuminators and consequently require less electrical energy to generate the same light output. Once installed LEDs also require zero maintenance. Compared to bulbs they save costs on replacement parts, equipment hire (specifically cherry pickers) and labour.

From a combination of electrical savings, and reduced costs for maintenance and replacement parts, a single LED illuminator can provide annual savings up to GBP 368 compared to a 500W illuminator.

The cost savings for large systems are enormous. Changing 100 units of 500W bulbs to 100 units of high efficiency LEDs can save end users up to GBP 36,800 per year - and this is a figure based on minimum costs for labour and equipment hire to replace bulbs. When you consider that most installed CCTV systems have a projected operational life of 10 years this amounts to a total ten year saving of GBP 368,000 for switching a 100 light system to high efficiency LED's.

Consider as a summary:

- Maximum saving on 1 illuminator of GBP 368 per year
- Over 10 years this is a total saving of GBP 3,680

- Maximum saving on 100 illuminators of GBP 36,800 per year
- Over 10 years this is a total saving of GBP 368,000

In addition to the cost savings, the reduced electrical consumption of LED illuminators deliver a lower carbon footprint (and the resulting tax benefits for end users).

Raytec have provided an interactive cost savings calculator that can be used to compare the operational costs and carbon footprint of LED illuminators with any type of bulb based illuminator. The cost savings calculator is available from Raytec to all end users, consultants and specifiers free of charge.

Summary

The future of CCTV lighting is green. New LEDs provide all the power and distance of bulb based illuminators with the advantages of delivering a more secure site and massive savings in operating and maintenance costs. Next time you need CCTV lighting do the planet and your pocket a favour - go green. It's a win-win scenario.