Thermoelectric generators can reliably power outdoor sensors and wearable electronics
Researchers have developed a new thermoelectric generator (TEG) that can continuously generate electricity using heat from the sun and radiant elements that release heat into the air. Working day or night, even in cloudy conditions, the new self-powered TEG can provide reliable power for small electronic devices such as outdoor sensors.
“Traditional power sources, like batteries, have limited capacity, require regular replacement or recharging, and can be inconvenient and unsustainable,” said a research team leader at Jimei University in China. One Jing Liu said: “Our new His TEG design offers a sustainable, continuous energy solution for small devices and can address the constraints of traditional power sources such as batteries.”
A TEG is a solid-state device that uses temperature differences to generate electricity with no moving parts. In Optica Publishing Group’s journal Optics Express, Liu and a multi-institutional team of researchers can simultaneously generate the heat and cold needed to create a temperature difference large enough to generate electricity even in the absence of the sun. Describes and demonstrates his new TEG. outside. Passive power supplies consist of easily manufactured components.
“The unique design of our self-powered thermoelectric generator allows it to operate continuously regardless of the weather,” said Liu. “With further development, our TEG has the potential to impact a wide range of applications from remote sensors to wearable electronics, facilitating more sustainable and greener approaches to enhancing our daily lives.”
Improved TEG performance
When a temperature gradient is created in a thermoelectric material, electrons flow from the hotter part to the colder part, creating an electric current. TEGs based on this phenomenon exist, but they tend to produce unstable temperature differentials and do not produce enough power to be useful.
To address these limitations, researchers have developed a new type of TEG. It uses a component called an ultra-broadband solar absorber (UBSA) to capture sunlight and heat one side of the generator. At the same time, another component called a planar radiatively cooled emitter (RCE) dissipates heat to cool the other side. Both UBSA and RCE can be applied to flexible substrates and can be useful, for example, in powering wearable devices.
The UBSA’s heating capacity is much greater than the RCE’s cooling capacity under normal sunlight intensity, so the researchers placed the RCE on top of the UBSA, which has a larger area. When sunlight hits the entire device, the unshaded part of UBSA absorbs the sun’s energy and heats up, causing his RCE at the top to start cooling. It converts the temperature difference caused by combining heating and cooling into electricity.
At night or on cloudy days, the temperature difference is greatly reduced because there is no direct sunlight. However, although less efficient than on a sunny day, there is still a temperature difference that can be used to generate electricity.
night power generation
To test the device, researchers conducted outdoor experiments under different weather conditions. They monitored the device’s voltage output and found that it could generate power continuously, day or night, even during cloudy daytime conditions. The device achieved a peak voltage output of 166.2 mV in sunny daytime conditions. This is enough to power small sensors and devices. Sunny night and cloudy day conditions produced 14.7 mV and 95 mV, respectively.
“The innovative method of combining solar heat and radiative cooling enables the TEG to generate electricity without interruption,” said Haoyuan Cai, a member of the research team. “This could improve access to critical services, especially in remote and underdeveloped areas where conventional power sources are not available.”
Researchers are currently working to further optimize the device’s efficiency, durability, and scalability, and plan to test its long-term stability and reliability under a variety of conditions. We also want to explore the possibility of mass production at reasonable cost to improve device performance and adaptability to different applications.
Original: New passive device generates power continuously day and night
Than: Jimei University
