Researchers at Swansea University's SPECIFIC Innovative and Knowledge Center has manufactured a new 3D printed thermoelectric device, which converts heat into electric power with an efficiency factor over 50 percent higher than the previous best for printed materials and cheap to produce in bulk.

In the UK, around one-sixth of all the energy used by industry ends up as waste heat, emitted into the atmosphere. A huge step forward in helping the industry cut its energy bills and reduce its carbon footprint is to harness this industrial waste to create electricity.

Thermoelectric materials turn differences in temperature into electric power or vice versa. They are used in fridges, power plants, and even some smartwatches that are powered by body heat.

In a previous study, it was shown that a material called tin selenide (SnSe), a compound made up of tin (Sn) and selenium (Se), has high potential as a thermoelectric material. The issue is that the methods used to manufacture it require lots of energy and are therefore expensive.

The work of the Swansea researchers comes in here. The method they have developed is potentially quite low-cost for industry because it enables SnSe thermoelectric generators to be produced quickly and easily in large quantities.

They formulated tin selenide into a type of ink which they could print to test its properties. The next step was to develop a kind of 3D printing technology to produce a small thermoelectric generator made out of the ink.

The innovation could be of particular benefit to industries where high temperatures are involved in the manufacturing process. One example is steelmaking, which generates vast amounts of heat and requires immense electrical power. Therefore, recycling the heat into power has the potential to boost energy efficiency significantly.

The research team is from SPECIFIC Innovation and Knowledge Center, a Swansea University-led project which develops technologies for reducing carbon emissions and demonstrates how they can be applied to buildings and industry.

According to the leader of the research team, Dr. Matt Carnie, turning waste heat into electrical power can boost energy efficiency significantly, cutting bills and reducing carbon emissions. The findings of the researchers reveal that printed thermoelectric materials using tin selenide are a promising way forward.

The team developed a device, and it is the best-performing printed thermoelectric material recorded to date, with the efficiency factor improved by over 50 percent compared to the previous record. Also, it is cheap to produce in bulk compared with established manufacturing methods. There are more works to be done, but the work of the team shows that this technique, combining efficiency and economy, could be quite attractive to energy-intensive industries.