PSMA Update

his year's Nobel Prize for physics was awarded to Mr. Isamu Akasaki and Hiroshi Amano of Japan and Shuji Nakamura of University of California, Santa Barbara, for "the invention of efficient blue light-emitting diodes (LEDs), which has enabled bright and energy-saving white light sources."

These three scientists working together (Japanese team) and separately (UCSB), developed new technology to produce blue light from semiconductors in the early 1990s. Though others had produced red and green LEDs, the blue LED from which white light is produced, had eluded scientists. And even though red and green LEDs are extensively used in many displays of clocks and calculators, it is the blue LED that is expected to change the lighting world in the 21st century.

The blue LEDs will revolutionize the lighting world because they consume less energy/power/electricity for the same amount of lumens or illumination, when compared to incandescent light bulbs or compact fluorescent light (CFL) light bulb. LEDs consume one tenth of electricity compared to incandescent light bulbs and half of CFLs. In addition, LEDs last for longer times, more than 40 times incandescent light bulbs and seven times the CFLs. From the electricity consumption standpoint and its longer lasting nature, blue LED is a significant invention.

This is truly a deserving Nobel Prize that fulfills the original intention of Alfred Nobel which stated that the prize should be awarded to an invention that benefitted mankind. By some accounts, almost 25% of the electricity is used to illuminate world. So a widespread use of LEDs will have significant impact in energy saving: in terms of power generation and consumption.

The widespread use of LEDs will also have a significant impact on the power electronics, as all LEDs need drivers/power supplies to power them. If the rosy projections for the LEDs materialize, then LED drivers/power supplies will emerge as single largest category of power supplies, even surpassing the external power supplies (EPS) for portable electronics. As LEDs are expected to change the lighting world, LED drivers/power supplies will change the shape and structure of the power supply/ electronics industry.

Interestingly, there is equally important other side to the current Nobel story: In 1921, the Nobel Prize for physics was awarded to Albert Einstein* "for his services to Theoretical Physics and especially for his discovery of laws of the photoelectric effect". Photoelectric effect is the fundamental physics behind the electricity generation using solar cells.

So these two Nobel Prizes in physics, awarded about 90 years apart, have the reverse physical phenomena:

These two inventions are already changing the way electricity is generated and used, not only in rich countries but in poorer parts of the world as the New York times states, "...In Africa, millions of diode lamps designed to run on solar power have been handed out to replace polluting kerosene lamps".

These two 20th century inventions will change the nature of electricity generation, electricity usage and nature of power electronics in the 21st century, for the generations to come.

* Albert Einstein did not receive the Nobel Prize for the Theory of Relativity, a subject of significant controversy in 1921 with many different explanations. He actually received the prize in 1922, but did not attend the ceremony. Einstein wanted the prize, not for its prestige as he was already famous, but for the money. He had promised his divorced wife, Mileva, that he would give her the prize money as settlement, if and when he received the prize.

The views expressed in this article are solely of Mohan Mankikar. They do not represent the views of PSMA. Mohan Mankikar has been a part of the power supply industry for over twenty five years. An active member of the PSMA since its founding, he had been a board member of the PSMA and currently serves on the Advisory Council.