In the realm of renewable energy research, Tom Markvart, a professor at the University of Southampton, has made notable contributions to the understanding of energy conversion processes. His latest work, published in the journal “Energy & Environmental Science,” explores the fundamental thermodynamic similarities between solar cells and thermoelectric generators, offering insights that could enhance the efficiency of these technologies.
Markvart’s research demonstrates that both solar cells and thermoelectric generators can be considered as isochoric engines—engines with constant volume—when they are at open circuit, meaning no current is flowing. In this state, these devices generate a finite chemical potential, which manifests as a voltage at their terminals. This finding underscores a previously overlooked thermodynamic similarity between the two technologies.
The study also reveals that the maximum energy efficiency of these devices is inherently lower than the Carnot efficiency, a benchmark often used in the literature. The Carnot efficiency represents the upper limit of efficiency for any heat engine operating between two temperatures. Markvart’s work shows that this limit is not achievable due to the temperature variation of the Seebeck coefficient, a measure of the voltage generated in response to a temperature difference in thermoelectric materials. However, the research suggests that more sophisticated strategies could be developed to recover some of these losses.
When these devices operate at finite current, additional losses occur, which can be modeled using finite-time thermodynamics. This branch of thermodynamics considers the effects of time and irreversibilities in real-world processes, providing a more accurate picture of how energy conversion devices perform under practical conditions.
The practical implications of this research are significant for the energy industry. By understanding the fundamental limits and losses in solar cells and thermoelectric generators, engineers can develop more efficient designs and strategies to maximize energy output. This could lead to improvements in renewable energy technologies, making them more cost-effective and competitive with traditional energy sources.
Markvart’s work highlights the importance of a deep, thermodynamic understanding of energy conversion processes. As the world continues to transition towards renewable energy, such insights will be crucial in optimizing the performance of these technologies and accelerating the shift away from fossil fuels.
The research was published in the journal “Energy & Environmental Science,” a leading publication in the field of energy research. The study provides a valuable contribution to the ongoing efforts to improve the efficiency and viability of renewable energy technologies.
This article is based on research available at arXiv.