Today’s crystalline silicon photovoltaic panels could be widely deployed by mid-century to help mitigate climate change. However, new nanomaterials could make for better, more efficient and less expensive solar panels in the future.
“We need to be deploying and improving today’s technology and at the same time setting the groundwork for emerging technologies that we might discover in the lab. It’s critical that we push forward on both fronts,” explained researcher and MIT graduate student Patrick Brown of the Department of Physics.
The research was conducted by Vladimir Bulović, an MIT professor of Emerging Technology associate dean for innovation; Tonio Buonassisi, an MIT associate professor of mechanical engineering; Robert Jaffe, an MIT Professor of Physics; and graduate students Brown and Joel Jean of the Department of Electrical Engineering and Computer Science. They assessed all of the current solar technologies available and found that though crystalline silicon solar panels currently make up about 90 percent of the PV solar power that’s installed across the world and that it’s an efficient and reliable source of harvesting energy.
However, they found that further reducing the costs of silicon PV is becoming more difficult. “Since 2008, the cost of the module has dropped by 85 percent, but the BOS [i.e., the balance of systems] cost hasn’t changed much at all,” MIT said. “Today, the solar module is responsible for just one-fifth of the total cost of a residential installation and one-third of the cost of a utility-scale installation in the United States. The rest is the cost of the BOS.”
The assessment found that for numerous reasons the cost of silicon PV will be hard to bring down further for a number of reasons—silicon isn’t very good at absorbing sunlight so it needs a thick, brittle layer and needs to be mounted on glass. Nanomaterials, the report found, “Could be easier and cheaper to manufacture; they could be made into ultrathin, lightweight, flexible solar cells that would be easy to transport and install; and they could offer unique attributes such as transparency, opening up novel applications such as integration into windows or textiles.”
“While the typical silicon solar cell is more than 100 microns thick, the typical nanostructured solar cell—one that uses QDs or perovskites—can be less than 1 micron thick,” Bulović says. And that active layer can be deposited on flexible substrates such as plastic and paper, with no need for mechanical support from a heavy piece of glass.
“Since no single technology—established or emerging—offers benefits on all fronts, the researchers recommend rapidly scaling up current silicon-based systems while continuing to work on other technologies to increase efficiency, decrease materials use, and reduce manufacturing complexity and cost,” MIT said.
“Today’s emerging technologies are improving far faster than currently deployed technologies improved in their early years,” Bulović explained. “But the road to market and large-scale deployment is invariably long.”
The MIT group also proposed a new framework for evaluating solar technologies, based on the complexity of the light-absorbing material as opposed to the generational model that researchers had relied on since 2001. The new model they propose is based on the number of atoms in the molecule or crystal unit that forms the building block for the material, according to MIT. It recognizes the complexity from a single atom of silicon to perovskite crystals and quantum dots and compares them on one scale. “We find that there’s some correlation between complexity and the performance measures that we’re interested in,” Jean said of creating the method of evaluating solar technologies.Tweet