As a civilization, we are proficient with the “boil water, make steam” method of turning various heat sources into power we feed our infrastructure. Away from that, we can use solar panels. But what if direct sunlight is not available either? A team at MIT demonstrated how to extract power from daily temperature swings.
Running on temperature difference between day and night is arguably a very indirect form of solar energy. It could work in shaded areas where solar panels would not. But lacking a time machine, or an equally improbable portal to the other side of the planet, how did they bring thermal gradient between day and night together?
This team called their invention a “thermal resonator”: an assembly of materials tuned to work over a specific range of time and temperature. When successful, the device output temperature is out-of-phase with its input: cold in one section while the other is hot, and vice versa. Energy can then be harvested from the temperature differential via “conventional thermoelectrics”.
Power output of the initial prototype is modest. Given a 10 degree Celsius daily swing in temperature, it could produce 1.3 milliwatt at maximum potential of 350 millivolt. While the Hackaday coin-cell challenge participants and other pioneers of low-power electronics could probably do something interesting, the rest of us will have to wait for thermal resonator designs to evolve and improve on its way out of the lab.
[Experimental Fun] shows us how you can create a cola power generator that runs on nothing more than cans of cola including the container and a little bit of sodium hydroxide to speed the reaction up.
This might sound a bit crazy, but it seems you can power an engine on little more than your favorite fizzy drink and the cut-up remains of an aluminum can. What happens is that aluminum and water create a chemical reaction when mixed together, which gives off hydrogen. Normally this reaction is very slow and would take years to make any noticeable marking on the aluminum, but with a little help from sodium hydroxide the reaction is sped up to such a rate that hydrogen is produced quite quickly.
The crazy contraption they created has a reaction chamber which then feeds the hydrogen through condenser then to a bubble filter made from a bottle filled with water. After that it is on through a carbon filter to get rid of any impurities, and finally it is fed directly into a two-stroke engine’s fuel line. Then engine still needs an electric start from a battery, but after that it runs directly on the hydrogen created during the reaction from the chamber.
This is quite a cool project, however you could replace the fizzy drink with water and still get the desired effect. Since the drink comes with the aluminum cans it seems like quite a good fuel though. There are other crazy fuels out the for the avid DIY hacker, but just be careful and don’t blow yourself up.
Continue reading “Coke Can Fueled Power Generator”