Energy Harvesting for Efficient Power Generation

Recent examples of very efficient thermal to electrical energy conversion over small temperature ranges near room temperature suggest that pyroelectric/thermodielectric energy conversion has the potential to far exceed any other alternative energy scavenging approach. Efficient pyroelectric/thermodielectric energy conversion could be made practical if materials with the appropriate properties were identified, produced, characterized, and deployed in thermodynamic energy harvesting cycles that were matched to these specific material properties in order to optimize conversion efficiency. In particular, the highly nonlinear behavior of the pyroelectric and dielectric properties as a function of temperature near the Curie temperature of a ferroelectric material offers the potential for much more efficient energy harvesting in this temperature region. As such, realization of efficient pyroelectric/thermodielectric energy conversion requires a series of ferroelectric materials with Curie temperatures that span the temperature region of interest. This proposed research effort will grow single crystal materials with Curie temperatures that lie within the 700 °C – 1000 °C range and characterize their pyroelectric and dielectric properties at temperatures near the Curie temperature with high electric fields and low frequencies consistent with potential efficient energy harvesting thermodynamic cycles. BENEFIT: The significance of alternative energy strategies has become increasingly apparent in recent years due to extreme volatility in traditional energy markets. While the economic and geopolitical turmoil that results from global reliance on limited energy resources has peaked and receded several times in the past century, the now commonly accepted realization that our hydrocarbon based energy threatens catastrophic climate change makes the development of alternative energy strategies critical. Compared with other alternative energy strategies, pyroelectric power generation has several distinct advantages including high efficiency, environmentally friendly, broad applicability, low cost, low maintenance, and easily scalable. The pyroelectric effect can convert heat from any source to electrical power. As such, it can be used to efficiently convert energy from zero greenhouse gas sources such as geothermal, ocean thermal, solar, or nuclear power. Pyroelectric energy conversion can also be used to increase the efficiency of traditional power plants by scavenging waste heat discharged through flue stacks and cooling towers. In addition to clean and/or more efficient power generation at the source, pyroelectric energy conversion can be used at the point of power consumption to recapture heat generated from nearly any industrial process and convert it back into electrical power thereby improving net energy efficiency of end users. Due to the projected low cost of manufacture, ease of use, low maintenance requirements, and scalability, pyroelectric energy conversion can be used throughout the electrical power continuum from large scale producers to industrial and residential customers to small scale personal electronics.