Researchers at Stanford University believe they’ve got the answer to the biggest problem with solar power generation systems—their inability to work at night. The research team has been working on groundbreaking technology that draws on radiative cooling, a phenomenon that takes place after the sun has set. It’s an incredibly exciting development in renewable energy with particular potential for application in off-grid systems.
Radiative cooling is the answer to the shortcoming of solar generation
Radiative cooling, which involves the heat given off by the Earth’s surface, takes place on clear nights and is a natural process that allows infrared energy to radiate into space. Electricity can be produced by harnessing the temperature difference between an object and the surrounding air. The reason why radiative cooling works best on clear nights is because cloud cover tends to reflect infrared radiation back to Earth, reducing the cooling effect required for the temperature difference.
The Standford researchers have managed to generate small amounts of power by attaching thermoelectric generators to solar panels, facilitating the collection of the heat dissipating from the Earth. The modified panels only have an output of about 50 milliwatts per square meter at night, but it’s expected that this will be scaled up as the technology develops.
The nighttime power generation capacity is small, but sufficient for small-scale applications
Despite the nighttime energy output being far below the 200 watts per square meter that standard solar panels generate during sunlight hours, it is still enough to power low-energy devices such as LEDs and sensors.
Shanhui Fan, the lead researcher on the Stanford team, highlighted that while the energy output is minimal for now, there’s considerable room for improvement. As the design and efficiency of the radiative cooling technology advances, these panels could become a valuable supplement to traditional solar energy systems to generate power during the night.
A different kind of solar innovation comes in the form of California’s solar train project, which will make the United States the first country in the world with a completely solar-powered bullet train network.
Off-grid areas will benefit most from panels capable of producing power in darkness
The Standford team’s development has the potential to bridge the energy gap in regions that aren’t connected to the grid. There are an estimated 770 million people across the globe who don’t have access to electricity, and this technology could deliver vital lighting, heating, and power to areas lacking resources.
Since this technology can be retrofitted into existing solar cells, it offers another benefit in the form of an affordable option to enhance renewable energy reliability.
A third advantage of the innovation is reduced reliance on costly batteries, which are also pollutants that require mineral mining and contribute to environmental damage.
The benefits of solar electricity generation
The generation of electricity from solar energy is critical as the world moves to new ways of producing clean energy. These are the reasons why solar energy is one of the fundamental solutions in the renewable power sphere:
- Carbon footprint reduction: Solar energy doesn’t rely on the burning of fossil fuels, which lowers carbon emissions.
- Clean and sustainable: Solar electricity cannot be depleted and it doesn’t produce harmful by-products.
- Economic growth and job creation: The installation, operation, maintenance, and development of solar power systems create employment. Countries that manufacture and export solar equipment benefit from GDP revenue.
- Energy independence: Countries that reduce their dependence on fossil fuels will develop more robust economies.
As with any new technology, there are challenges to overcome before it can be accepted in the mainstream realm. However, there’s significant potential to solve global energy issues and the development of nighttime solar panels is a major step towards the adoption of sustainable energy solutions.
While researchers work on theories, models, and prototypes for future options, the conventional solar electricity sector is moving full steam ahead. Singapore recently granted conditional approval for solar-generated electricity to be imported from Australia via undersea cables stretching thousands of miles.