Monday, July 28, 2008

New Solar - LED Lighting System

LED Light Xela Teco 600

Solar - LED Light

This summer in Guatemala we designed a Solar - LED lighting system for people who live without access to electric power.

Our system consists of a 10 watt solar panel and two LED light fixtures rated at two watts each. The system has enough capacity to charge a cell phone and to run a small radio too. The prototype fixture shown above is made in part from recycled water bottles from the Black Cat Hostel in Quetzaltenango, (AKA Xela) Guatemala.

On the hike up to visit one of the families who will be testing our lighting system we were met by one of the children from the household. She knew we were on our way because her mom had called her on her cell phone. We found from our surveys that many people living without power have cell phones. Cell phones are almost free in Guatemala. I purchased my Guatemalan cell phone for about $15.00 U.S., and it came with $15.00 in minutes pre-installed. The phone was essentially free!

This leaves the rural poor with a new problem. Where do they charge their phones? Most have to hike in to the phone store (there are phone stores almost everywhere) and wait while their phone is charged or if they are lucky they have a friend within walking distance who has power or a battery. Whatever the system, it takes hours to charge a cell phone if you live without electricity.

Our Solar-LED system has a 12 volt battery and an automotive outlet (in the old days we called these cigarette lighter outlets). This feature makes our system more like a home power system than just a light fixture. Amazingly, 10 watts is a lot of power if you are accustomed to living with no power at all.

What our questionnaires and conversations with people who will be using our lights uncovered is that people need more than just light. People want to be connected.

Our lighting system will cost about as much as people spend in a year on kerosene lamps, candles and batteries. In addition to having more light and better visibility, they will also be able to save the time and energy spent to keep their cell phones charged.

The estimated savings in Carbon Dioxide per household per year is about 750 pounds. Our system is designed to last over 20 years, with the batteries changed every 5 years.

Later this year when we have the final list of materials and the final circuit board designed we will publish all of the technical specifications on

This project is sponsored by the Lindbergh Foundation. Our design partner for the project is the Xela Teco Workshop in Guatemala, with special design help from Jose Ordonez and Carlos Alvarez Cahuex.

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