Switching to a LED lighting is happening fast not only because of the savings that can be made and the environmental benefits but because there are now documented improvements on human well-being as a result of this type of lighting.

LEDs (light-emitting diodes, or solid-state lighting), are ultra-efficient, have an extended working life, significantly reduce CO2 emissions even compare to compact fluorescent bulbs, slash power bills and minimise replacement (i.e. maintenance) costs.

Tests by the Pacific Northwest National Laboratory have shown that for the same amount of lighting an incandescent light bulb consumed 60 watts of electricity, while the LED model used just 12.5 watts and the CFL 15 watts.

Many of the modern designs simply slot into the same fixtures and fittings as incandescent bulbs, but their flexibility also means that designers are producing ever more intriguing and versatile lighting possibilities.

Health benefits

Added to these benefits, research from LightingEurope (prepared by A.T. Kearney and the German Electrical and Electronic Manufacturers' Association (ZVEI)) finds evidence that LED bulbs could present an array of health benefits. Some of the claims sound a little tenuous, but, because the lights give off light that is more akin to natural daylight, the more plausible ones include:

• Increased employee or student motivation and commitment;
• Improved concentration and energy;
• "Mood support" in wellness and dining areas;
• Enhanced drug efficacy, e.g., of antidepressants (in hospitals);
• Reduced therapy times and capacity requirements.

As a result, a trend has begun for recommending that LED lighting be used in hospitals, health centres, schools and offices. The concept has been dubbed 'Human Centric Lighting' (HCL) and refers to the biological and visual impact lighting can have on the health and wellbeing of humans.

The research does not exclusively concentrate on LED lighting but on variable lighting, in particular, and allowing individuals to adjust their lighting level, and the use of daylight-frequencies in lighting, which is known to improve melatonin levels that are related to mood meaning that HCL has the power to help people suffering from mental health diseases such as anxiety and depression.

LEDs' efficiency

LEDs possess increased efficiency because energy of the bulb is utilized to produce light rather than wasteful heat; they last for an average of 40,000 hours, compared to incandescent bulbs which burn out in approximately 1,000 – meaning that you would have to buy 40 incandescent bulbs to match the longevity of LEDs – making their higher upfront cost recoupable within months.

The US Environment Protection Agency has calculated that LED lights will save 88 terawatt-hours of electricity from 2010 until 2030 – enough to power seven million homes for an entire year. And in Britain it has been calculated that the country as a whole could save £1bn in energy bills every year – the equivalent of £50 per household – simply by switching to LEDs, and save around 5 million tonnes of carbon dioxide annually.

In the UK, 20% of the 633 million light bulbs in use are already estimated to be LEDs. There are still over 506m incandescent light bulbs in use in homes and businesses – even reducing this number by a small percentage would have a great knock-on effect for the country's green economy.

LED strip lights.

General rules for improving lighting efficiency

Of course, any lighting project should both strive to turn the lights off as well as reduce wattage when the lighting is on. If it can be turned off when the space is unoccupied, the most cost-effective solution is to add occupancy sensors or basic timers to reduce the load to zero whenever possible. In restrooms, storage areas and break rooms, a simple, inexpensive commercial sensor can easily reduce lighting cost by as much as 70% to 90%.

Public spaces, retail stores, stairwells, and parking garages are examples of areas that will usually be lit regardless of occupancy either because of safety or to provide an inviting setting for visitors or products displays.

Many upgrades include improved fixtures and ballasts that contribute to lower maintenance cost. An indirect benefit of reducing the number bulb replacements is a reduction of the time workers spend on ladders and lifts, which leads to less injuries and worker downtime.

If fixtures are also being replaced, you should favor features that allow for faster access to the lamp during replacement. Quick connect wiring plugs permit faster and safer installation and maintenance; sealed housings prevent dirt build-up and corrosion in humid environments. These are just some examples of features that can reduce or even eliminate the need for costly maintenance.

Replacing incandescent, halogen and high-intensity discharge (HID) lighting with fluorescent or LED equivalents can also reduce the cooling load by a measureable amount as well. This, of course, depends on location – warmer climates will benefit more from the cooler lighting in the summer months; the savings can be as high as 1kWh in cooling for every 3kWh reduction in lighting.

T5 LED lighting.

Often, managers wait until something breaks down before replacing it but in the case of lighting there is a business case for replacing them early rather than waiting. It translates to an interest rate on the investment that is extremely favourable.

This is because cost reductions that reduce the ongoing utility costs impact immediately upon the bottom line. This can be illustrated by the following examples:

And the effect of this on the net profit margins of some typical businesses:

(thanks to Noesis for the examples).

Other environmental benefits

"The light-emitting diode lamp is a rapidly evolving technology that, while already energy efficient, will become even more so in just a few short years," said Marc Ledbetter, who manages Pacific Northwest National Laboratory's solid-state lighting testing, analysis and deployment efforts. "Our comprehensive analysis indicates technological advancements in the near future will help people who use these lamps to keep shrinking their environmental footprints."

PNNL has produced a report which examines the total environmental impact from cradle to grave of LEDs, including the energy and natural resources needed to manufacture, transport, operate and dispose of light bulbs. It looked at 15 different impacts including the potential to increase global warming, use land formerly available to wildlife, generate waste and pollute water, soil and air, and compared three kinds of light bulbs: LEDs, compact fluorescents (CFLs), and traditional incandescent light bulbs.

CFLs were found to cause slightly more environmental harm than today's LED lamp in all but one of the 15 impact areas studied. The one standout area was generating hazardous waste that must be taken to a landfill, because LED lights include a component called a heat sink, a ribbed aluminum segment that is attached to the bottom of LED bulbs. Aluminum heat sinks absorb and later dissipate heat that's generated by the light bulb, preventing it from overheating. The process to mine, refine and process the aluminum in heat sinks is energy-intensive and creates several byproducts such as sulfuric acid that must be taken to a hazardous waste landfill.

But this study was conducted in 2012 and already the latest generation of LED lights are solving some of the earlier environmental problems.

How many more reasons to you need to switch to LED lighting?