A Solar Panel That Works Without The Sun
Solar panels have come a long way since the technology was first invented. But the major drawback of using photovoltaics on Earth is that it eventually gets dark. Researchers at MIT have developed a solution to this problem. They’ve come up with a photovoltaic cell which doesn’t need any sunlight and is built into a button sized generator that can run your smart-phone for a week.
In the image above, you have many of these generators that require a fuel, like butane, from which they generate heat. The material that the generators are made out of are pockmarked with billions of tiny (we’re taking nanometer scale here) holes. When this pockmarked surface heats up, it emits light in a few very specific wavelengths that are then captured by photovoltaic cells that are tuned to those specific wavelengths, and then you get electricity.
The basic principle of the new generators is the same as the one that feeds electricity to your house. A fuel is heated and converted into electricity. With a power plant, the heat is used to boil water to steam, and the steam is used to turn a turbine, which generates electricity. The new generators follow the exact same principle, but with no moving parts and a one step process, they are many times more efficient. Their prototype uses butane as a fuel but you can use anything that burns, coal, wood, uranium, you name it.
So as a consumer, what can you look forward to? Currently, MIT’s generator is about three times more efficient than a lithium ion battery, and since they run on butane, you just need to refill them and they’re good to go. With a little bit of work, MIT researchers say that they can triple their current efficiency, and since all this can be scaled down, you can expect a new smart phone using this technology to run for a solid week without a recharge in the near future.