NEW ENERGY SOURCE?

Scientists Convert Heat to Power Using Organic Molecules, May Lead to New Energy Source
February 15, 2007 (University of California, Berkeley via Science Daily)
- Researchers at the University of California, Berkeley, have successfully generated electricity from heat by trapping organic molecules between metal nanoparticles, an achievement that could pave the way toward the development of a new source for energy.

- The discovery…published…Feb. 15 in Science Express, an electronic publication of the journal Science, is a milestone in the quest for efficient ways to directly convert heat into electricity. Currently, the dominant method of power generation involves burning fossil fuels to create heat, often in the form of steam, to spin a turbine that, in turn, drives a generator that produces electricity.
- An estimated 90 percent of the world's electricity - from power plants to car engines - is created through this indirect conversion of heat…a great deal of heat is wasted and released…
- For the past 50 years, utilizing this wasted heat has been a major focus of research into thermoelectric converters, which employ a simpler, more direct method of generating electricity.

Such converters rely upon the Seebeck effect, a phenomenon in which a voltage is created when the junctions of two different metals are kept at different temperatures…thermoelectric generators operate at a paltry 7 percent efficiency, compared with the 20 percent efficiency rate for traditional heat engines…[and] are made up of exotic, expensive metal alloys, such as bismuth and tellurium, making them too costly and impractical…
- The new UC Berkeley study marks the first time the Seebeck effect has been measured in an organic molecule, laying the groundwork for the development of more cost-effective thermoelectric converters…
- The researchers coated two gold electrodes with molecules of benzenedithiol, dibezenedithiol or tribenzenedithiol, then heated one side to create a temperature differential. For each degree Celsius of difference, the researchers measured 8.7 microvolts of electricity for benzenedithiol, 12.9 microvolts for dibezenedithiol, and 14.2 microvolts for tribenzenedithiol. The maximum temperature differential tested was 30 degrees Celsius (54 degrees Fahrenheit)…

- The next step for the researchers includes testing different organic molecules and metals, as well as fine tuning the assembly of the structure…[and] the field of organic thermoelectricity could open doors to a new, inexpensive source of energy…