Illuminating the Developing world.-Energy Eff. Conf. Cont.

by Ginosar  

Energy Efficiency Conference



Illuminating the Developing world.

Evan Mills, Ph.D.
Staff Scientist, Lawrence Berkeley National Laboratory
Research Affiliate, Energy & Resources Group, UC Berkeley


There is a substantial global lighting inadequacy. It can easily be seen in the famous satellite picture of the Earth night sky. US, Europe, East side of China, Australia East coast and the like have considerable lights. The poor areas of the world, about one and a half billion people, Africa, much of China, much of interior India, have no electricity. They have been using kerosene lights for a century. And many do not have even that.


The fuel cost of these primitive kerosene lights is around $40 B a year, emitting 190 Million Tones of CO2. Replacing these lights with self generating electricity is equivalent to eliminating CO2 from 30 million cars. And obviously would provide more reliable, steady and non polluting source. The inside air pollution from kerosene is considerable too.

"The most promising modern illumination is by LED because of their high light to energy efficiency, small size, ruggedness, and ability to run on low voltage. It is natural to produce local electricity, away from any power grid, by extremely small PV systems or through temporary connections to grid nodes such as cellphone charging shops. The miniature power supplies may be as low as 3% and thus are a key problem.

The idea is appealing but there are problems and barriers.  PV charging has high initial costs, although well-designed systems can pay for themselves in less than a year.  Poor-quality manufacturing can result in unnecessarily inferior products that spoil the market.  Current LED are up to 60 lpw (lumens per watt.) The best LEDs are approaching 100, but the worst ones tested are around 10 lumens per watt.

Major international initiatives from the World Bank and the U.S. Department of Energy are addressing these issues by instituting better consumer information and quality-assurance testing and rating systems.


Dr. Matania Ginosar wrote:

Evan, thank you very much.

I am puzzled by your statement that PV can be paid back in one year. Here roof locations are, according to our utility  $9500/kW installed, and up to 1400 kWh/yr output in good locations.


Dear Matania,

We are talking about developing country applications for extremely poor people who only have a lantern or two for lighting.  We are powering replacement lights with electricity and providing higher levels of energy services, but we aren't electrifying the whole home.  The system you described is of course running many lights plus major appliances.

The systems we are working with are less than one watt, because the LED itself is less than one watt. 
Households can easily spend $50-$100/year on kerosene lighting, depending on local fuel prices and how they use their lamps. 

LED systems are retailing for $20-$50 with small pv panels.

This is really the power of miniaturization (small light, small battery, small solar cell).  The systems are of course considerably less expensive without the solar cell (if they can be charged at cell-phone charging shops, at work, etc.)

Make sense?

Dr. Matania Ginosar wrote:

It make sense. I tried last night my 8 LEDs low-cost flashlight. At 4.5V and 0.2 Amps it is close to one watt. But the light in a dark room was very weak, may be equivalent to 10 W incandescent bulb.


We are so accustomed to high intensity light, we probably do not grasp how thankful those without electricity could be even with that small illumination.

Another possibility is that you have a much higher efficiency LEDs than those in my cheap flashlight.




We've seen LED efficacies ranging from 10 to 60 lpw (and that was several years ago).  Best ones are approaching 100 lpw now!  ~  Evan



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