Blackbody-cavity Ideal Solar Absorbers

TL;DR

This paper introduces a scalable blackbody cavity solar absorber with near-perfect solar absorption and minimal infrared emission, achieving high operational temperatures and surpassing existing nanofabrication-based SSAs, suitable for industrial use.

Contribution

A novel blackbody cavity design that is easy to manufacture using traditional methods, offering high performance and scalability for solar thermal applications.

Findings

Achieves 880°C stagnation temperature under 10 suns

Surpasses performance of nanofabrication-based SSAs

Compatible with large-scale industrial manufacturing

Abstract

Spectrally selective solar absorbers (SSAs), harvesting sunlight into heat, are the key to the concentrated solar thermal systems. Current SSAs' designs using photonic crystals, metamaterials, or cermets are either cost-inefficient or have limited applicability due to complicated nanofabrication methods and poor thermal stability at high temperatures. We present a scalable-manufactured blackbody cavity solar absorber design with nearly ideal properties. The unity solar absorptivity and nearly zero infrared emissivity allow for a stagnation temperature of 880C under 10 suns. The performance surpasses those state-of-the-art SSAs manufactured by nanofabrication methods. This design relies on traditional fabricating methods, such as machining, casting, and polishing. This makes it easy for large-scale industrial applications, and the "blackbody cavity" feature enables its fast-integration to existing concentrated solar thermal systems.