Green —and universal — photonics: 'Sustainable Energy for All'

October 2012 issue
of SPIE Professional

It's estimated that three billion people — more than 40% of the world’s population — use wood, coal, charcoal, and other matter for cooking and heating and that 1.5 billion people lack access to electricity.

The human, social, economic, and environmental costs of this inequity are tremendous because energy is fundamental to health, safety, comfort, and progress for all seven billion people on Planet Earth.

Yet access to energy varies widely depending on whether people live in a wealthy or a poor country.

But more attention is being paid to this growing problem.

As Steve Eglash (Stanford University Energy and Environment Affiliates Program) and Kara Fisher (Duke University) write in the October issue of SPIE Professional, the optics and photonics community are finding sustainable ways to generate, convert, store, and use energy without destroying the planet.

The importance of sustainable energy was reinforced when the United Nations declared 2012 as the International Year of Sustainable Energy for All.

SPIE is a supporter of this initiative and its members are addressing the problem by finding opportunities in both developed and resource-poor parts of the world to build better and cheaper solar cells. They are also getting industry and academia to work together on sustainable energy for all; and they have devised new business models so that solar cells, batteries, and LED lights reach some of the world's poorest people.

Eglash and Fisher discuss some of the ways that optics and green photonics are helping to create universal access to energy, make energy use more efficient, and expand the use of renewable energy.

"Light-management techniques are making thin-film solar cells more efficient and less expensive. Better light emitters, phosphors, and lenses are making LEDs brighter and more efficient. Wind turbines use LIDAR to 'see' wind gusts and lulls moments before they arrive," they write.

"Improved display screens using LCDs or OLEDs are expanding the functionality of cell phones, which are often a person’s primary or only access to the modern information economy. Video cameras enable smart energy-efficient-buildings. Optical sensors are used to monitor air, water, and food quality."

The pay-as-you-go business model seems to be doing great in poor countries. Under this concept, organizations such as Eight19, Simpa Networks, and others buy the energy infrastructure (PV systems, etc.) and provide it to users who then pay on a daily or weekly basis for only the electricity they use. After a while, the equipment is fully paid for, and the users own their own small power plants.

"Changing the world requires the right technology and a means for deploying that technology where it is needed," Eglash says.