Researchers at the University of Michigan have made a significant leap in the efficiency of thermophotovoltaic (TPV) cells, devices that convert heat into electricity. This innovation brings the technology closer to practical use on the grid, potentially transforming energy storage and generation.
Key Findings
- High Efficiency: The new air-bridge TPV cells have demonstrated up to 44% efficiency in converting heat to electricity.
- Wide Band Gaps: These cells are effective across a range of band gaps from 0.74 to 1.1 eV, reflecting nearly all below-band-gap radiation.
- Lower Temperature Compatibility: The cells function efficiently at temperatures below 1,500°C, making them suitable for integration with stable emitters.
How It Works
TPV cells operate similarly to solar cells but convert infrared radiation from a hot source into electricity, rather than visible light. The innovative air-bridge design incorporates a thin air layer and a gold reflector to trap useful photons, sending non-useful ones back to the heat source for re-emission. This design enhances photon recycling and boosts efficiency.
Practical Applications
The team envisions TPV cells being used in heat batteries, which store excess renewable energy during peak production hours and convert it to electricity later. This method offers a cost-effective and scalable alternative to lithium-ion batteries and does not rely on water sources like hydroelectric storage.
Future Prospects
With a current efficiency of 44%, the researchers are optimistic about reaching 50% efficiency in the near future. This advancement, supported by U-M Innovation Partnerships, is poised to revolutionise energy storage by providing a robust, high-efficiency solution that complements renewable energy sources.
This significant stride towards efficient and practical heat-to-electricity conversion not only enhances energy storage capabilities but also supports the broader adoption of renewable energy, aiding global decarbonisation efforts.
Source
Bosun Roy-Layinde et al, High-efficiency air-bridge thermophotovoltaic cells, Joule (2024). DOI: 10.1016/j.joule.2024.05.002
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