Waste heat is not cool, say US scientists

- Jul 15, 2019-

How to harness the excess heat solar panels generate alongside electricity is an increasingly important question for the industry.

In most PV installations that heat is not put to any purpose and reduces power output and long term performance stability – although researchers in Saudi Arabia this week revealed a device that can use it to power water distillation without hindering generation levels.

Waste heat is also a major problem in consumer appliances, with a University of Utah team which believes it has found a way to reduce limits on thermoelectric generation citing estimates as much as two thirds of energy consumed annually in the U.S. is wasted as heat.

Different strategies exist for dealing with such waste heat, most still at the research stage. One possibility is thermoelectric generation, which can produce electricity from differences in temperature. A theoretical limit for the process – the blackbody limit proposed by Max Planck more than a century ago – was believed to limit its usefulness. Several studies in recent years, though, have found ways around the blackbody limit to achieve higher rates of thermal energy transfer.