The majority of alternative energy researchers are trying to make renewable energy bigger and bigger. They are trying to build solar plants and wind farms that can power larger percentages of the grid, batteries that can hold more kilowatt-hours, and biofuels with high energy density. At the same time, there is a growing interest in capturing the small bits of energy that otherwise go to waste. While these technologies will never (at least for a very, very long time) provide energy for a car or household, they are still sparking development by some big names.
Such as Intel, for instance. Intel just demonstrated a system which can utilize the energy in radio waves to power small electronic devices. By using a TV antenna pointed at a radio tower 4 miles away, the Intel team was able to collect about 60 microwatts â€“ admittedly insignificant when you are thinking on the scale of kilo, mega and even terawatts â€“ but enough to power a small device, in this case a thermometer and its LCD display.
RF technology is especially exciting when you think about pairing it up with a new generation of energy monitoring systems. Energy monitors are, like the thermometer, small computers that draw relatively small amounts of power. If that power could be â€œbroadcastâ€ out across many square miles from a radio source, such devices could potentially go without batteries or connection to the electric grid, thereby offering the ultimate flexibility.
Another technology that Intel is working on is thermoelectricity. In a nutshell, when you run an electric current through certain materials, you can make one side of the material hot and the other side cold. This works in reverse as well; if you heat up one side of the material and cool down another, an electric current will be generated.
Intel is building small thermoelectric devices to be built into their chips. By running small amounts of electricity through the devices, the thermoelectricly-cooled plates can be used as heat sinks to draw heat away from processors. It is important to realize that, even with such devices, you still need to put in about as much energy (in electricity) as you draw out (in heat). The difference between a thermoelectric device and a fan is that, with the former, you can pinpoint the spots that generate the most heat and thus remove it in a more efficient way.
Another thermoelectric application involves using such materials to generate electricity from otherwise useless waste heat generated by engines and other types of machinery. Komatsu, a Japanese firm that manufactures, among other things, construction equipment, is developing thermoelectric modules to capture heat from said equipment. The latest device to come out of their labs has been able to achieve a conversion efficiency of 7.2%, generating 24 watts per module, given a temperature difference of 280 degrees (C) on one side and 30 on the other.
So donâ€™t forget about small power â€“ there are many useful ways to utilize watts, even when they are not on such lofty orders of magnitude.
Via Green Car Congress, Treehugger
written by Global Patriot, January 29, 2009
written by Sayan, January 31, 2009
|< Prev||Next >|