In the recent weeks, a few countries have been able to operate entirely off of renewable energy for an extended period, and they have been quite successful in this regard. But most Western industrialized nations still have a long way to go before getting there. Largely, this is because the various technologies are far from perfect and lack efficiency. Additionally, such nations have much higher energy demands.
For instance, solar cells have long been known to achieve a sunlight-to-electricity conversion efficiency of 24%. That's not enough to cut it for most industrialized nations. But just this week, a press release reports that engineers from Australia have beaten that record with their new solar cell configuration.
Dr Mark Keevers and Professor Martin Green at the University of New South Wales have constructed a new solar cell that a has an efficiency of 34.5%, almost 44% higher than the current record. Their new configuration makes use of a 28-cm2 four-junction mini-module. The cell collects sunlight, a prism splits up the rays into bands that are processed by each of the four junctions, absorbing the most energy out of sunlight.
Around 2014, the same team from UNSW set a world record of over 40% in efficiency with a solar cell configuration that makes use of mirrors to concentrate light. The one they just created takes in normal, unconcentrated sunlight.
The previous record was held by the US Company Alta Devices. At the 24% efficiency, their cells are built on a 800-cm2 surface area. This is obviously an enormous difference than what it utilized by the Australian technology.
Theoretically, these particular four-junction modules have a limit of 53% in efficiency, what more could be achieved if they scaled it to Alta's surface area?
Green asserts that the technology is moving at an unexpected pace, explaining that studies have shown that a 35% efficiency of solar cells that use unconcentrated light will be achieved by 2050. While the researchers certainly made history with their technology, it's unfortunately unlikely to make it to commercial use in the near future. Four-junction modules are not easy to make, nor are they cheap.