As promised, NRGLab sent me an “inner report” that offered additional information on the research that went into the creation of its poly crystals. While the report is quiet on the design of its SH box, it does offer a glimpse of the technical underpinnings and challenges that were overcome on the road to generate electricity from ambient temperature differences.
Today, I outline additional information about the company’s poly crystal technology.
Building on previous research
As noted in my earlier blog, thermoelectric is nothing new, with the Seebeck thermocouple effect discovered all the way back in 1821. While significant progress has been achieved in applications of the Seebeck effect in semiconductor materials, the thermoelectric systems developed on the basis of this effect do not satisfy key parameters required for real-world application and commercialization. Specifically, they either offer a low efficiency, are too expensive for widespread deployment – or both.
NRGLab’s research was focused on exploring new and practical types of thermoelectric conversion of energy by semiconducting liquid anisotropic media. Of course, given that the majority of activities in the field of alternative energy engineering are aimed either at searching for new sources of non-renewable energy or at improving available methods and materials for energy conversion, it can be argued that NRGLab is attempting to solve the energy problem from an altogether different angle.
According to NRGLab, its research with various mixtures of liquid crystals with dopes imparting semiconductor properties that were added to the medium saw a phenomenon that it considers as a “nonlinear Benedix effect.” The company says this proves the existence of a new principle of thermoelectric conversion discovered in anisotropic semiconducting organic liquids. Though the theory behind the process has yet to be finalized, a thermoelectric conversion with the efficiency close of that of the Carnot cycle is hence shown to be a possibility.
With this in mind, the hunt was on for a suitable electrode. The company says it has considered a number of materials ranging from stainless steels, carbon, aluminum, copper, titanium, titanium nitride, nickel and ITO. The greatest effect was seen in aluminum and titanium nitride, with the company settling on the use of aluminum for the SH box.
While NRGLab says it does not consider its findings as “record-breaking,” the company says that the efficiency and the electric power obtained by its experiments are higher by more than an order of magnitude than those of organic thermoelectric converters based on carbon nanotubes.
To underscore the breakthrough work here, NRGLab director Sergey Sorokin told me that a temperature difference of just one degree Celsius is required to generate an electrical current, compared to at least 30 degrees Celsius required with other thermoelectric conversion technologies available today.
Not as simple as it looks
Though the discovery has great ramifications in terms of non-polluting source of power, harnessing it is not as straightforward as it sounds. According to the report, the electrical parameters of the converter depends on a nonlinear and often non-unique manner dependent “not only on the difference in the electrode temperatures, but also on the temperatures themselves.”
Moreover, heating or cooling dynamics exerts an explicit effect, while an unsteady behavior of the dependences of the thermal voltage and thermal current on time can be observed at steady temperatures. Obviously, that the company has put together the SH box shows that it has already surmounted these challenges, and I am personally looking forward to seeing it out on the market.