Published on January 20th, 2011 | by Susan Kraemer3
14% Nanomaterial Breakthrough in Waste Heat Electricity Could Turn Dirty Industries in US Into Electric Power Generators
January 20th, 2011 by Susan Kraemer
A group of material scientists, physicists, and chemists at Northwestern University in Illinois have just created a new nanomaterial that enables 14% of heat waste to be converted to electricity, a scientific first.
A lead-based nanomaterial is made by putting nanocrystals of rock salt into lead telluride. Lead telluride, which is composed of lead and tellurium ions on a lattice, has long been considered one of the most promising candidates, as it is already relatively efficient in transforming heat to electricity, but there have been technical problems to overcome. That is what these researchers have achieved.
Northwestern University’s research is not the first attempt at nanoscale inclusion in bulk material to improve the waste heat conversion performance of lead telluride. But it does it better, by using nanostructures to reduce electron scattering which previously reduced the conversion efficiency.
Until now, devices that convert waste heat into electricity have had efficiencies in the 5 – 10% range.
Nevertheless, waste heat is one of the lowest cost methods of generating baseload electricity because it is a free byproduct in any industry that uses heat, such as cement makers, paper mills and steel or glass manufacturers.
The amount generated by industries such as these can be considerable. Finland gets a third of its electricity from waste heat generated by its heavy industrial users, which have long had a financial incentive to sell excess power to the grid. In some states there are incentives to supply the grid with waste heat energy.
For example, in California, SMUD, Sacramento’s public electric utility offers a very generous Feed-in Tariff for co-generation (waste heat) electricity. Public policy encouraging waste heat electricity sales through a Feed-in Tariff has a real political benefit in enabling a clean grid.
By paying for electricity generated by heavy industries, a lot of the motivation to join with the fossil industry that works to obstruct a switch to clean renewable energy is dissipated. Even coal and gas power plants have the opportunity to reduce their carbon cost per unit of electricity supplied to the grid with co-generation.
The study was just published by the journal Nature Chemistry.