The overall concept is explained in this one sentence: “A solar thermal fuel is like a rechargeable battery, but instead of electricity, you put sunlight in and get heat out, triggered on demand,” – Jeffrey Grossman, Engineer MIT
Here is a simple diagram that shows the concept:
When heat from the sun warms a fluid, it changes the molecules so that this heat can be released at a later time on demand when it is exposed to a catalyst.
What I see as a huge instant benefit is the efficiency of the system. Solar panels are around 20% efficient, which is horrible, but some of the best solar heat collectors such as the evacuated tube collectors can be in the high 90%. Being that heating accounts for about half of the average home energy use, this method makes a lot of sense.
It is likely you have experience with a fluid that operates similar to this – sodium acetate heating pads. These are plastic containers with a simple chemical solution. When you heat them up, the solution liquefies and stays that way until activated. There is a tiny metal, flexible disc inside. When the disc is bent or “clicked”, it triggers a chain reaction crystallization process of the chemical that heats up. This is of course oversimplified compared to the Solar Thermal Fuel technology, but is suffice to convey the concept in simple terms.
In some third world countries, when the sun goes down, there is no light for the people. If there is, it is usually a kerosine lamp that burn indoors. The light is useful, but some claim that one night of breathing in the fumes is the same as smoking 40 cigarettes. And to top it off, 20% of a family’s income every week pays for the fuel.
The folks at LEDsafari are doing some great work using a very simple method. They use a cell phone battery with the electronics removed, an LED, a switch and a small solar cell to build a low cost solar lamp.
Little by little their method is getting a bit more sophisticated. LEDsafari is now adding a diode to keep the battery from sending power to the solar cell and burning it up. Also, a resistor is added to limit the current the battery delivers to the LED so it lasts longer. Total cost is about $2.00.
There are some simple ways to improve upon these methods. But for now, this project has been a blessing for thousands of people. Without LEDsafari’s solar lamp program, many would be sitting in the dark or spending money just to breath unhealthy fumes. This just shows that something so small and simple really can make a huge difference in people’s lives!
Saving Money, Reducing Fuel & Increasing Health
The income savings and health benefits are obviously priceless. It is important to understand this isn’t a hand-out. LEDsafari holds workshops to teach people how to empower themselves by learning how to build their own solar lamp! Just look how happy those kids are in the picture up above. This is not just a technical skill, but a way to increase their self-esteem and build confidence in the fact that they can help themselves.
Support this project by telling your friends, sharing this page and visiting: LEDsafari