American scientists have developed a material that beats the record for converting waste heat into power – something they hope will be incorporated into clean energy investment.
According to research published this week in Nature, American scientists have developed a material that beats the record for converting waste heat into power – something they hope will be incorporated into clean energy investment.
In what is being hailed as "a giant leap", the material achieves the highest efficiency ever for scavenging heat from a source and transforming it into power, its inventors say.
According to the team, as much as 20 per cent of the heat that disappears out of car exhausts and the chimneys of power stations and factories could be recovered as electricity.
The compound is a doped derivative of lead telluride, a semiconductor first used in the Apollo moon landings to provide astronauts with a renewable, thermoelectric power source.
For years, the efficiency rating in thermoelectrics, known by the unit of ZT, was stuck at 1. The new material has smashed this with a ZT rating of 2.2, outstripping the previous record reached earlier this year of 1.7.
The study was led by Professor Mercouri Kanatzidis, a chemist at Northwestern University in Chicago.
"At this level there are realistic prospects for recovering high-temperature waste and turning it into useful energy," said Kanatzidis.
as for the cost of the new material, it's not clear at this point, but Kanatzidis claims that if manufactured on a large scale, "it should be nearly the same as bulk lead and tellurium combined."
He also discounts fears of toxicity, saying that the lead-tellurium bond was "very stable environmentally" – the compound occurs naturally as a mineral called altaite.
In a commentary appearing in Nature, Tom Nilgesa of the Munich Technical University in Germany, says it is "a feat that is not only a tremendous step for one group, but also a giant leap for thermoelectrics."