Solar tech that generates 15x more energy has potential to revolutionize green energy

A new thermoelectric device boosts the electricity generation capability of a little-known solar technology by 15 times. Instead of relying on conventional solar cells, it pulls electricity straight from heat created by concentrated sunlight.

The prototype belongs to a class of solar thermoelectric generators, devices that turn heat differences from sunlight into electricity.

By increasing how much usable power comes out of a device this size, the team shows that an old idea can be pushed further.

How solar thermoelectric works

Most home solar panels turn sunlight directly into electricity inside semiconductor wafers. Solar thermoelectric devices, instead, use a temperature difference across special materials to generate a steady electric current.

When one side is hotter than the other, the Seebeck effect, a thermoelectric process where heat drives charge, pushes carriers toward the cooler side.

As that imbalance grows, a voltage builds up and can be tapped through wires to do useful work.

The work was led by Chunlei Guo, a professor of optics at the University of Rochester. His research focuses on using ultrafast lasers to sculpt material surfaces for energy and photonics applications.

Earlier generations of solar thermoelectric generators converted well under one percent of incoming solar energy into electricity under practical conditions, which made them a niche curiosity.

Most rooftop photovoltaics sit near 20 percent efficiency, so closing that gap requires smarter heat management rather than entirely new materials.

Tungsten and ultrafast lasers

At the hot side, the team reshapes a thin tungsten plate using femtosecond lasers, tools that fire extremely brief light pulses. Those pulses carve a forest of tiny structures across the metal, turning its surface nearly black.

By roughening the metal in this controlled way, the surface acts as a selective solar absorber, a coating that soaks up visible sunlight efficiently.

Because it emits relatively little infrared heat, the treated tungsten reaches higher temperatures under the same sunshine than an untreated plate.

To keep that heat from leaking away into air, the researchers stretch a clear plastic film over the hot surface. This cover creates a tiny greenhouse effect, a pocket of air where reduced convection lets the tungsten stay much hotter than the surroundings.

Rather than inventing a new semiconductor, the Rochester group concentrates on managing light and heat around the module so that more energy crosses it.

Together, the blackened metal and plastic chamber upgrade the hot side of the generator without adding moving parts or bulky optics.

Designing a better cold side

On the cold side, the same laser system patterns thin aluminum foil with rows of tiny grooves and ridges.

Because this creates a highly micro-structured surface, covered in fine features that greatly increase area, the metal can shed heat much more quickly.

In open air the treated aluminum works as a compact heat sink that combines radiation of infrared energy with efficient contact with the air.

Heat is pulled away from the thermoelectric module faster, so the cold side stays cooler while the hot side remains intense.

Tests show that this redesigned sink removes roughly twice as much heat as a plain aluminum block of the same size.

Even with both the blackened tungsten and the micro-structured aluminum attached, the generator weighs only about one quarter more than the bare commercial module.

That modest change matters for portable uses where every extra ounce counts, such as sensors in remote fields or gear carried by a person.

Thermoelectric solar implications

Across industry and research labs, engineers already use small thermoelectric generators to supply power for remote sensors and controllers.

Networks of devices, known as the Internet of Things, link everyday objects so they can share data and run with minimal human attention.

In low power sensor nodes, the required electricity falls in the microwatt to milliwatt range, making thermoelectric harvesters attractive wherever a temperature gradient exists.

Small thermoelectric generators using this treatment could sit on hot pipes, walls, or engine housings, powering loggers or communication modules without extra wiring.

Another active area is wearable electronics, small devices worn on the body that monitor health or activity without restricting movement.

One heat powered patch uses a thermoelectric system to run monitors from the skin to air temperature difference.

Looking ahead, solar thermoelectric modules that capture sunlight and heat could support vehicle chargers, road signs, or emergency boxes away from grid power.

Even though the Rochester device remains experimental, it shows how managing light and heat at surfaces can give solar technologies options beyond photovoltaic panels.

Challenges and next steps

Turning metal surfaces into precise optical structures with lasers is still a delicate lab job, even if the underlying process is relatively simple.

Scaling these textures to large areas or curved industrial parts will require systems that can scan quickly, align accurately, and stay affordable.

Keeping performance high over years also means checking how the blackened tungsten, plastic film, and structured aluminum handle rain, dust, and heat cycles.

Outdoor tests in different climates will be needed to reveal whether surfaces stay dark, clean, and firmly attached under real weather.

If those hurdles can be cleared, solar thermoelectric technology could move from powering instruments to supporting energy uses where panels are hard to install.

As engineers pair it with conventional photovoltaics and renewables, they may build hybrid systems that squeeze more electricity from sunlight and waste heat.

The study is published in Light: Science & Applications.

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