A US invention using quantum physics may have just solved renewable energy’s biggest problem

Rice University engineers have developed a quantum-inspired thermal emitter for thermophotovoltaic (TPV) systems that promises over 60% spectral efficiency—a leap far beyond typical TPV performance—but the full system’s conversion efficiency remains much lower.¹

A Leap Forward in Clean Energy Storage

TPV systems convert heat into electricity by first emitting thermal radiation via a thermal emitter and then capturing those photons with photovoltaic (PV) cells. Rice’s breakthrough improves that emitter using spatially tuned nanostructures, addressing a core challenge: matching emission to PV response instead of wasting energy.²

Did you know?
TPV is not new—it was first constructed in the 1950s—but until now, system efficiencies remained in the 30–40% range.³

Tackling the Intermittency Challenge

Renewables like solar and wind are reliable in resource but not in timing, requiring storage. TPV offers a path around reliance on lithium-ion batteries by storing excess energy as heat and converting it to electricity on demand. Rice’s emitter could enhance the attractiveness of thermal energy storage (TES) systems by improving energy retention and conversion.⁴

The Thermal Emitter at the Core

The innovation uses a tungsten base topped with silicon nanocylinders acting as resonators. This quantum-inspired approach enables photon-by-photon control, resulting in high spectral selectivity and over 60% efficiency at the emitter level—not overall conversion.

Did you know?
Systemic TPV efficiencies remain modest: even with advanced emitters, total heat-to-electricity conversion typically stays in single digits due to PV limitations and thermal losses.

Precision Through Quantum Control

The novelty lies in non-Hermitian optical design—a quantum concept that engineers selective emission with both brightness and precision—overcoming the long-standing trade-off in TPV emitters.² This could make high-efficiency TPV systems compact and scalable.

Potential Beyond Current Limits

Rice’s team sees space and remote applications as promising early adopters, where compact, highly efficient power sources outweigh cost. But wide use in grid storage will require both system-level optimization and advances in high-efficiency PV cells.

What It Means for Renewable Adoption

If integrated with next-gen PV cells, Rice’s emitter could enable TPV systems to store and return energy more efficiently than battery-based systems under the right conditions. This technology may not be a silver bullet yet—but it represents a key piece in a more sustainable energy future.

Footnotes

1. Rice University — “Quantum-inspired design boosts efficiency of heat-to-electricity conversion” (Nov 21, 2024): https://news.rice.edu/news/2024/quantum-inspired-design-boosts-efficiency-heat-electricity-conversion

2. Nature article “Non-Hermitian selective thermal emitter for…”: high spectral efficiency (> 60%) in TPV system using quantum design: https://www.nature.com/articles/s44310-024-00044-3

3. Nature / NREL — record TPV system efficiencies around 41% (NREL/MIT) and 40% (LaPotin et al., 2022): https://www.nrel.gov/manufacturing/news/program/2022/capturing-light-from-heat-at-40-percent-efficiency-nrel-makes-big-strides-in-thermophotovoltaics ; https://www.nature.com/articles/s41586-022-04473-y

4. ScienceBlog (Nov 22, 2024) — Rice’s emitter could make thermal energy storage a practical alternative to batteries: https://scienceblog.com/quantum-physics-inspires-more-efficient-way-to-convert-industrial-heat-into-electricity/