How thermoelectric generators work

Thermoelectric generators produce electricity by harnessing heat. Thermocouples and thermopiles are the most familiar types, notably so, to those who have ever fixed a hot water tank or furnace when it refused to stay lit.

Thermoelectric generators produce electricity by harnessing heat. Thermocouples and thermopiles are the most familiar types, notably so, to those who have ever fixed a hot water tank or furnace when it refused to stay lit.

A German physicist, Thomas Johann Seebeck, discovered this effect in 1821, when he discovered that a compass needle would deflect when exposed to two dissimilar metals connected at either end.

Today, the metals used are most commonly bismuth telluride (Bi2Te3) or lead telluride (PbTe).

Thermoelectic generation is ideal for producing DC electricity in remote locations for powering communications system, navigation, or well site units. It can be married to photovoltaic arrays as a backup when cloud, fog or darkness reduces insolation. With outputs to 550 watts and up to 48 volts DC for single units, driven by the combustion of propane, or natural gas, these units offer substantial output, but with weights to 680 kg, they are not something that can be put in your pocket.

Electronics are quickly scaling down to where computers, glasses, watches and other devices are becoming part of our daily dress.

The problem with these small-sized semiconductors is how to keep them supplied with energy.

The Korean Advanced Institute of Science and Technology (KAIST) have developed an interesting solution.

Using a glass fabric, they have taken the TE technology on an advanced evolutionary path. Byung Jin Cho and his team have developed a reliable power source that uses the heat of the human body to produce electricity. They have found a way to minimize thermal losses while maximizing energy density without a bulky substrate.

TE generators over the years have evolved from either the previously mentioned inorganic metal thermopile technologies or organic polymers. Polymers are light flexible and ideal for placing next to our skin, but unfortunately they have low power output.

The inorganic TE generators are simply too heavy and awkward to be strapped to an arm.

The researchers accomplished this by making a near-liquid paste of n type Bi2Te3 and p type Sb2Te3, the two different metals required, then using a screen printing technique, applied these pastes to a glass fabric.

Screen printing allows them to arrange the different constituents in a specific pattern. The materials are absorbed into the spaces between the fibres, forming a film of small dots on the surface.

The glass fabric acts as a upper and lower substrate, which allows the two metals to operate, producing a millivolt electrical current strong enough to power electronics.

With a 31C difference between a human body and ambient air temperature, a 10-by-10-cm flexible TE generator made this way can generate 40 millivolts of electrical energy. Although the KAIST prototype was conceived for developing electronic devices that can be worn, like smart glasses, smart watches, pace makers, etc., it has the potential to generate electrical power on larger scale, such as using waste heat from an engine.

It’s an alternative type of energy harvesting developed to power our life.

Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003. His column appears every second Friday in the Advocate. Contact him at:

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Red Deer’s Kyle Moore, 26, will be a houseguest on Season 9 of Big Brother Canada. (Photo courtesy Big Brother Canada)
Red Deer man will be a houseguest on Big Brother Canada

A Red Deer man will be a houseguest on the upcoming season… Continue reading

Red Deer Public Schools says that in the absence of additional funds from the provincial government, there was no consideration of using alternate classroom sites in the district. (AP Photo/Gregory Bull)
Red Deer Public Schools launches online engagement process

Red Deer Public schools is seeking community input to help ensure a… Continue reading

Red Deer Rebels defenceman Mason Ward battles with a Medicine Hat Tigers’ forward during the WHL Central Division season opener. (Photo by Rob Wallator/ Red Deer Rebels)
Tigers come back to spoil Red Deer Rebels home opener

It’s been nearly 345 days since the Red Deer Rebels last played… Continue reading

Students walk into Hunting Hills High School, which is one of the Red Deer Public Schools with solar panels on its roof. (Photo by SEAN MCINTOSH/Advocate staff)
Red Deer high school was placed in lockdown following potential threat

Hunting Hills High School was placed in a lockdown Friday after Red… Continue reading

Red Deer Mayor Tara Veer says some details of the provincial government’s 2021-22 budget need to be ‘sorted out’ when it comes to the hospital expansion funding. (File photo by Advocate staff)
More detail needed regarding hospital funding, says Red Deer mayor

Red Deer Mayor Tara Veer says some information is unclear regarding the… Continue reading

An arrest by Red Deer RCMP is facing online scrutiny. No charges have been laid and the incident is still under investigation. (Screenshot of YouTube video)
Red Deer RCMP investigating violent arrest caught on video

Police say officer ‘acted within the scope of his duties’

A health-care worker prepares a dose of the Pfizer-BioNTech COVID-19 vaccine at a UHN COVID-19 vaccine clinic in Toronto, Thursday, Jan. 7, 2021. A single dose of Pfizer-BioNTech's COVID-19 vaccine is barely enough to cover the average pinky nail but is made up of more than 280 components and requires at least three manufacturing plants to produce. THE CANADIAN PRESS/Nathan Denette
From science to syringe: COVID-19 vaccines are miracles of science and supply chains

OTTAWA — A single dose of Pfizer-BioNTech’s COVID-19 vaccine is barely enough… Continue reading

Crosses are displayed in memory of the elderly who died from COVID-19 at the Camilla Care Community facility during the COVID-19 pandemic in Mississauga, Ont., on November 19, 2020. The number of people who would have died from a COVID-19 infection is likely to be much higher than recorded because of death certificates don't always list the virus as the cause of a fatality, experts say. THE CANADIAN PRESS/Nathan Denette
Death certificates don’t accurately reflect the toll of the pandemic, experts say

The number of people who would have died from a COVID-19 infection… Continue reading

Wetaskiwin RCMP say a Maskwacis man died after he was struck by a vehicle. (File photo by Advocate staff)
Clare’s Law in Saskatchewan used handful of times; Mounties review their role

REGINA — A first-of-its-kind law in Canada meant to warn those at… Continue reading

The Magpie river in Quebec is shown in a handout photo. THE CANADIAN PRESS/HO-Boreal River MANDATORY CREDIT
Quebec river granted legal rights as part of global ‘personhood’ movement

MONTREAL — With its kilometres of rapids and deep blue waters winding… Continue reading

Thorough sanding of a table top is usually the first step to renewing a finish. Wax contaminants can sometimes still remain on a surface like this after sanding. Cleaning with rubbing alcohol and a rag gets rid of these contaminants without leaving a residue behind. (Photo by Steve Maxwell)
Houseworks: Fixing wood finishes

Q: How can I stop polyurethane from beading up on a mahogany… Continue reading

Need a knife? There are knives of all shapes and sizes at The Kitchen Store.
Hints from Heloise: Finding a good set of kitchen knives

Dear Readers: A good set of knives in the kitchen is a… Continue reading

Runner Melissa Bishop-Nriagu speaks to the media at the opening news conference at the Canadian Track and Field Championships Thursday, July 25, 2019 in Montreal.THE CANADIAN PRESS/Ryan Remiorz
Canadian athletes struggling to find competition as they try to qualify for Tokyo

Canadian athletes struggling to find competition as they try to qualify for Tokyo

Most Read