book_cover_big.gifRecently the European Commission  (EC) has released a green paper on how to accelerate innovative lighting technologies (http://ec.europa.eu/information_society/digital-agenda/actions/ssl-consultation/index_en.htm). The focus in the entire document is on solid state lighting (SSL) only. About 20% of the world wide total electrical energy generated  is used to generate light. SSL is expected to play a substantial role in an energy efficiency improvement of 20% (EC ambition versus 1990). It is anticipated that SSL (which can be either LED or OLED based technology) can save in combination with smart lighting management systems up to 70% of required electrical energy today. LED’s are expected to convert electrical energy  at an efficiency of about 60%, compare that to incandescent bulbs of only 2% and CFL’s of about 25%.

Looks OK at first sight isn’t ? But it totally overlooks that these new light sources will create new applications and therefore a possible risk that the net result is that we save much less or, even worse, spent even more of our electricity bill on lighting than today. This is comparable to the anticipated reduction in paper use with the arrival of the PC and high quality monitor screens. Well we know how that ended….. look for instance to the amount of junk mail that you find almost daily in your mailbox. Thus we will need to be careful how we apply SSL.

The EC is worried about Europe’s competitive position (quote from the report):

“The USA in 2009 put in place a long-term SSL strategy (from research to commercialisation). China is implementing a municipal showcase programme for LED street lighting involving more than 21 cities; it is granting significant subsidies to LED manufacturing plants and aims to create 1 million related jobs in the next 3 years. South Korea has defined a national LED strategy with the goal to become a top-3 world player in the LED business by 2012”

Two linked objectives are mentioned by the EC: 1) Develop the demand side (European users) and 2) Develop the supply side (role of  the European industry)

One of the problems to overcome is the high price of SSL: a 60W incandescent bulb cost about 1 Euro, a CFL about 5 Euro and a LED about 30 Euro. It is expected that by continuous price erosion in 2015 market share of CFL and SSL will be balanced. Not so far away!

An interesting article in Electronic Design News on SSL and CFL. Follow this link:

http://www.edn.com/blog/PowerSource/39403-Can_adding_a_reliability_standard_to_Energy_Star_actually_hurt_LED_lighting_.php

The article deals about a new proposed energy efficiency standard but has some real interesting quotes about CFL (compact fluorescense lamps). Read also the comments!

See also my earlier blog on CFL’s: https://secondlawoflife.wordpress.com/2010/04/06/reliability-of-compact-fluorescence-lamps/

book_cover_big.gifAs I said earlier, technology by itself can not solve our global warming problem. On the contrary, sometimes new technologies make things only worse (bio fuels for instance). But there are also many cases where technology certainly can help. A good example is that of solid state lighting (SSL). The light source in SSL is a light emitting diode (LED). Let me explain that a bit.

A LED is a device made out of semiconductor materials (for example Gallium Nitride, chemically noted as GaN). It is basically a diode with which you would normally rectify AC current. But by proper geometrical shaping and the right applied voltages the diode can also generate light. The principle of light generating in the LED (electron-hole recombination) allows that high efficiencies can be achieved because heat generation is strongly reduced compared to gas discharge or incandescent bulbs.

About 20% of all electrical energy is used for lighting. For a very long time we used the incandescent bulbs. They have a very low efficiency of converting the electrical energy into light: less than 2%, thus most of the electrical power going into the lamp is converted into heat. The introduction of fluorescent lamps (where a gas discharge is invoked) improves the efficiency considerable up to about 25% (see for instance  https://secondlawoflife.wordpress.com/2008/10/05/compact-fluorescence-lamps/).  An LED can improve this light/power efficiency with about a factor of two (so up to 50%), but can also exhibit a dramatic increase in life time (say a multiple of 10,000 hours versus 1000 hours for an incandescent bulb). Massive research is still ongoing to improve performance and color characteristics of the LED further. Generally it is expected that in the next 10 to 20 years there will be a major shift towards LED based lighting.

The US Department of Energy hopes that by 2025 the total electrical energy needed for lighting can thus be reduced up to 50%, which is of course a substantial number. This can eventually lead to a 10% reduction in overall electrical power requirement of the society.