Engineers have achieved conversion efficiencies exceeding 40% in solid-state thermal heat engines. The technology, known as thermophotovoltaics (TPV), converts infrared light emitted by ultra-hot thermal banks back into grid-ready electricity.
Operational Architecture
TPV systems capture heat from molten tin or graphite banks heated to over 2,000°C by excess renewable generation. When energy demand spikes, specialized photovoltaic cells harvest the radiant heat, operating without moving mechanical parts or turbine maintenance requirements.
Levelized Cost of Storage Metrics
Projections suggest TPV systems could drop long-duration energy storage costs below $0.05 per kilowatt-hour. This cost profile presents a competitive alternative to lithium-ion batteries and pumped hydro for multi-day grid stabilization.