New LED on the block

On Thursday, Philips announced that it has developed the world’s most efficient “warm white” LED lamp. Designed to replace the fluorescent tube lighting that is ubiquitous in offices and industrial facilities, the new TLED (tube-style light emitting diode) has the potential to reduce worldwide energy consumption by more than 7%.

According to a Philips spokesperson, their new prototype tube lighting produces 200 lumens per watt (200 lm/W). And it is expected to cost only slightly more than the equivalent strip lighting set-up (at 100 lm/W). Traditional bulbs only produce 15 lm/W.

But, the arguably more significant accomplishment with Philip’s new TLED is that it produces warm white (~2700K) light, the type of light prehat most people prefer for indoor lighting. An easy way to increase the efficiency of a bulb design is to increase the color temperature. So, the fact that Phillips managed to keep the temperature in this lower range, while still hitting the 200 lm/W rating, is even more impressive.

Globally, building lighting represents 15-19% of total energy consumption and florescent tube lighting accounts for more than half of the lighting market. In the context of Thursday’s announcement – if Philips’s new bulb makes it to market by the summer of 2015, it will have the potential to reduce worldwide energy use by more than 7%.

Old is Gold!

After the rush for CFLs now the spotlight is on LEDs. But how reliable are the claims? A Down To Earth report uncovers not so well known facts. CFLs were 300 per cent more energy efficient than incandescent bulbs; the figure has improved to 400 per cent now. The efficiency graph is not the same for LEDs. They are just five per cent more energy efficient than CFLs, according to the 2012 report by the US department of energy. But this report also predicts that by 2015 LED technology could become 300 per cent more efficient than CFL.

What about lifespan? It is said that LEDs have a lifespan of 25,000 hours compared to CFLs’ 8,000 hours. But LEDs have not been used in the real world for 25,000 hours, so the numbers are mere speculations. Low-end LED products, especially those made in China, are bound to flood the market, but they will surely not last 25,000 hours, say experts. CFLs, meanwhile, are eight times longer lasting than incandescent bulbs.
LED fixtures might be promoted as the way ahead, but they come with problems. For instance, an LED bulb is difficult to replace as it is available in panels. LEDs demand more controlled conditions and the lifetime of fixtures depends upon the source of energy supply. Even a nominal voltage fluctuation can damage LEDs. Another problem with LED lights is the amount of heat they produce.  Although LED chips, which work on DC current, generate negligible amount of heat, each light fixture has a transformer which converts the regular 120 volt AC current to 12 volt or lesser DC current. This conversion produces considerable amount of heat which is dissipated using heat sinks, adding equal if not more heat to the room than a tubelight.

Though the LED lobby often flags the absence of mercury in LED lights, researchers at the University of California have found presence of heavy metals in them. A 2010-11 study published in the Environmental Science and Technology states LEDs contain lead, arsenic and a dozen other dangerous substances. The study adds low intensity red LED bulbs are the worst offenders, while white LED bulbs, which contain the least amount of lead, have high levels of nickel. Like CFLs, disposal problems also plague LEDS.
The tubelight might be at the bottom of the lighting technology hierarchy but it beats both CFLs and LEDs at most levels. Not only is it cheaper but also almost twice as efficient as CFL and LED fixtures. With a proven lifespan of 20,000 to 30,000 hours, a tubelight is perhaps the best lighting option at our disposal today. Shows why it is prudent to wait and watch before jumping onto new technology bandwagons!

CFL dilemma

Are CFL's as good as they have been portrayed to be? Not really, if you go by what some experts are saying.

Typically the published life of CFLs is not achieved. Consumers are led to believe the lamp will last from 10,000 to 15,000 hours or more. Unfortunately these numbers do not take into account the lumen depreciation over time, and leads the customer to believe that when half of the interior walls of the lamp are dark, and light is still coming out, it is still ok to use.

More importantly however, these published numbers do not take into account the fact that these numbers are usually based on a minimum 7 hours of operation per start. As a result, if the lamp is turned on and off at a frequency less than 7 hours (which seems to be the typical application for compact fluorescents) the useful life of the CFL is dramatically less.

Clearer notes on the packaging, life based on lower on/off cycles, and life based on 70% of initial lumens would result in more accurate information.

That is what some experts say. However, some argue that it all depends on the kind of chokes used - whether internal or external. the latter is said to be better in performance.

care to share your experiences with these new-age light fluorescents that have taken over our homes?

Tried and tested

A recent study in the US looked at a comparison of CFLs and LEDs. The claim has been that LEDs are more efficient than CFLs. LEDs also cost more than CFLs but they last longer, so you’ll make up the initial cost over the lifetime of the bulb. Are these facts really true?

What the survey found was that lab conditions differed from 'real world' conditions. In a lab, which can be controlled for the best possible conditions, light can be generated at optimal efficiency. Because manufacturers are able to utilize components that are made to work together, they can claim to produce results with greater efficiency.

For instance, a leading LED-chip manufacturer announced they had achieved an efficiency of 231 lumens per watt in an LED chip. However, this was conducted in a lab where technicians were able to use lighting fixtures capable of producing such high output. In the “real world,” this LED-chip manufacturer does not sell a LED lighting fixture with a claimed efficiency over 75 lumens per watt.

Therefore, among other factors, consumers would not be able to produce as high efficiency in their own homes.

For the study, they used two roughly equivalent CFL and LED lamps that would commonly be used in the home. When comparing the two on paper, the efficiency of the bulbs is nearly identical, within 0.5 lumens per watt. However, with the “real world” being taken into consideration, there are certain environmental and consumer factors that make a case for both.

One factor is cost. If your primary concern is price, the CFL would be a better choice. Although the CFL has a shorter lifespan, even if you replaced the CFL three times to achieve an equivalent lifespan to the LED, you’d still have spent lesser than on the LED.

The bottom line is that in a household setting, where optimal components and ideal conditions cannot be controlled, the LED and CFL light bulb are very close competitors. The decision for one over the other should be made based on the need.

But in terms of quality of lumens delivered, ask any electrical engineer and he will tell you that the good old T5 FTL (or tubelight) is the best! While a CFL gives 50-65lumen/watt, the T5 or T8 gives up to 95 lumen/watt. Lamp life too is lesser for CFLs.

Then why are organizations connected to energy efficiency promoting CFLs? Any idea?

LEDs in the dock

Well, they are being touted as safe, green and efficient lighting and the alternative to incandescents and fluorescents. But now, the LEDs also stand exposed, according to latest research.

The light-emitting diodes marketed as safe, environmentally preferable alternatives to traditional lightbulbs actually contain lead, arsenic and a dozen other potentially hazardous substances.

Scientists at UCI and UC Davis crunched, leached and measured the tiny, multicolored lightbulbs sold in Christmas strands; red, yellow and green traffic lights; and automobile headlights and brake lights. Low-intensity red lights contained up to eight times the amount of lead allowed under California law, but in general, high-intensity, brighter bulbs had more contaminants than lower ones. White bulbs contained the least lead, but had high levels of nickel.

Lead, arsenic and many additional metals discovered in the bulbs or their related parts have been linked in hundreds of studies to different cancers, neurological damage, kidney disease, hypertension, skin rashes and other illnesses.

The question that rises is if the LEDs were properly tested for potential environmental health impacts before being marketed as the preferred alternative to inefficient incandescent bulbs. Often a new product is marketed for its advantages vis a vis other products in the market, but perhaps it is time to start independent testings, as this case shows.

Will be interesting to hear the other side of the story, though.

CFL is the winner

Researchers with Swizerland's Empa have investigated the ecobalances of various household light sources. In doing so not only did they take into account energy consumption, but also the manufacture and disposal processes. They also evaluated usage with different electrical power mixes. The clear winner is the compact fluorescent lamp.

In order to evaluate the total effect of a lamp on the environment over its entire life the researchers prepared a life cycle analysis for each kind. This takes into consideration the raw material and energy consumption of a lamp during its complete life cycle, from the production and usage to final disposal. The total point tally is a measure of the sum of all the damage the product in question inflicts on human health and the environment, as well as the usage of resources incurred during its manufacture.

For those wondering about the mercury aspect of CFLs, the environmental effects reduce by as much as 15 per cent when they are recycled instead of being incinerated. But even when they are incinerated in a waste disposal facility the much criticized mercury release is quantitatively insignificant.

This is because the overwhelming proportion of mercury in the environment is emitted by fossil fuel burning power stations. Depending on whether it uses brown or anthracite as fuel, a power station emits some 0.042 to 0.045 milligrams of mercury for every kilowatt-hour of energy it produces. A plant generating 1000 megawatts of power therefore releases 42 to 45 grams of mercury into the atmosphere every hour.

Any disagreements?

LEDs win top grades

Light-emitting diode (LED) streetlights perform best overall in terms of energy efficiency, lifetime, environmental impact and costs, according to the University of Pittsburgh. The team compared the lifecycle – from extraction of raw materials through fabrication and assembly to electricity consumption during use and finally disposal – of LEDs, high-pressure sodium (HPS) and metal halide lamps and the gas-based induction bulb.

LEDs though the most expensive options for streetlighting, consume only half the electricity of HPS or metal halide installations, last up to five times longer and produce more light. The analysis concurs with critics of LEDs that they do need considerable energy to produce and can be difficult to recycle, but they contain no mercury and fewer toxins such as iodine and lead.

The greatest impact of LEDs, however, comes when electricity consumption during use is considered – which is much more significant than that required for production. LEDs require much less energy than HPS or metal halide lamps.

The potential savings could be huge. The city of Pittsburgh, for example, could save $1 million a year in energy costs and $700,000 in maintenance by replacing HPS lamps with LEDs. That’s no small amount.

New light

Lighting accounts for approximately 50 percent of electricity consumed in homes, and homes account for around 30-40 percent of total electricity consumed in most cities. All of which makes the move to more efficient lighting imperative. CFLs and LEDs. While the former is disadvantaged by the mercury it uses, the LEDs are still to become commercially viable.

But is the mercury in CFLs really a concern? The European Commission cautions people to air out rooms and avoid using the vacuum cleaner if a CFL bulb with mercury in it gets broken. Although the quantity in the average CFL is no larger than the small tip of a ballpoint pen, direct contact with mercury can cause brain and kidney damage in humans and their animal pets.

CFL manucturers are adapting to this need. Some companies sell the light instead of the bulb; another prevents mercury contamination when broken.

But it is important to remember that fossil fuel based power generation also spread mercury in the air!

It has been estimated that with current U.S. power generation (which comes from more than 50 percent coal), switching to compact fluorescent bulbs in a big wave will reduce the amounts of mercury getting into our environment. At coal-fired plants (the biggest source currently of mercury emissions), 13.6 milligrams of mercury is emitted just to light up an incandescent bulb, while a CFL only would lead to (if incinerated, tossed out, or broken instead of recycled) 3.3 milligrams of mercury being emitted into the environment.

The mercury in a CFL is approximately one-quarter the amount emitted if an incandescent was used in its place, and that is if the CFL isn't recycled.

The answer lies in recycling of CFLs. Only 2 percent of CFLs have been recycled. The mercury in the bulbs also needs to be recycled given the need to stock on the mineral and prevent further mining. As nations switch to CFLs, it is necessary to have in place a recycling regulation. Does your nation have one?