the rise of solar energy
Paris (AFP)- Generating electricity from sunlight bouncing off the ground, working at night, even helping to grow strawberries: solar panel technology is rapidly changing as costs fall for a key segment of the energy transition world.
The International Energy Agency says solar power will need to increase dramatically this decade to meet the Paris climate target of limiting temperature rise to 1.5 degrees Celsius above pre-industrial levels.
The good news is that costs have dropped dramatically.
In a solutions report earlier this year, the Intergovernmental Panel on Climate Change said solar unit costs fell 85% between 2010 and 2019, while wind fell 55%.
“Some claim it’s the cheapest way humans have ever been able to generate large-scale electricity,” said Gregory Nemet, a professor at the University of Wisconsin-Madison and the report’s lead author.
Experts hope that high fossil fuel prices and energy security fears caused by Russia’s invasion of Ukraine will accelerate the adoption of renewable energy.
The momentum accelerated on Sunday with the ambitious US Climate Bill, which calls for $370 billion in efforts to cut greenhouse gas emissions by 40% by 2030.
An expert analysis from Princeton University estimates the bill could see five times the rate of solar additions in 2025 compared to 2020.
Nemet said solar power alone could plausibly account for half of the world’s electricity system by mid-century, although he cautioned against looking for “quick fixes”.
“I think there’s really big potential,” he told AFP.
The “photovoltaic effect” – the process by which solar cells convert sunlight into electrical energy – was first discovered in 1839 by French physicist Edmond Becquerel.
After decades of innovations, silicon-based solar cells began to be developed in the United States in the 1950s, with the launch of the world’s first solar satellite in 1958.
The IPCC said that of all energy technologies, small-scale ones like solar and batteries have so far proven to be faster to upgrade and adopt than larger options like nuclear.
Today, almost all of the panels that sparkle on rooftops and span vast fields are made in China using silicon semiconductors.
But technology is changing rapidly.
In a recent report, the IEA said these new solar cells were found to be one-fifth more efficient at converting light to energy than standard modules installed just four or five years ago.
There are also a host of new materials and hybrid cells that experts say could increase efficiency.
These include cheap, efficient and lightweight “thin film” technologies, such as those using perovskites that can be printed from inks.
Experts say they raise the prospect of a dramatic expansion of places where solar power can be harvested – if they can be made durable enough to withstand two decades of use.
Recent research has raised hopes that it might be possible.
In a study, published in the journal Science in April, scientists added metal-containing materials to perovskite cells, making them more stable with efficiency close to traditional silicon models.
Other research mixes materials for different purposes.
A study in Nature used “tandem” models, with perovskite semiconductors to absorb near-infrared light across the solar spectrum, while an organic carbon-based material absorbed the ultraviolet and visible portions of the light.
And what happens after sunset?
Stanford researchers said this year they had produced a solar cell capable of harvesting power at night, using heat escaping from Earth to space.
“I think there’s a lot of creativity in this industry,” said Ron Schoff, who leads the Electric Power Research Institute’s renewable energy and fleet-enabling technologies research.
Generating more energy from each panel will become increasingly crucial as solar power is deployed on a larger scale, raising concerns about land use and damage to ecosystems.
Schoff said an efficiency-enhancing design that’s becoming increasingly popular for large-scale projects is “bifacial” solar power.
These double-sided units absorb energy not only directly from the sun’s rays, but also from light reflected from the ground below.
Other solutions are to use the same space for multiple purposes, such as semi-transparent solar panels used as a protective roof for strawberry plants or other crops.
India pioneered the use of solar panels on canals a decade ago, reducing evaporation when they generate electricity.
California scientists say if the drought-prone U.S. state shaded its canals, it could save an estimated 63 billion gallons.
Construction of a pilot project is to begin this year.
All shapes, sizes
Experts say solar power will be part of a mix of energy options, with different technologies more suited to different locations.
Schoff said that ultimately these energy grids with more than 25% solar and wind power need ways to store the energy – with batteries or large-scale installations using things like pumped water or compressed air.
Consumers can also play their part, Nemet said, by shifting more of their energy use to daytime periods, or even hosting their own solar arrays in an Airbnb-like approach.
He said the modular nature of solar power means it can be deployed in developing countries with limited access to traditional grids.
“You could have solar on something as small as a watch and something as big as the largest power plants in the world,” he said.
“I think that’s what makes people excited about it.”
© 2022 AFP