+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
 
Loading...
{megaLeaderboard}
{normalLeaderboard}
News Article

UNSW nudges closer to physical limits of solar cell efficiency

Australian engineers deliver new world efficiency record with four junction mini-module


Mark Keevers with the four-junction solar mini-module built at the University of New South Wales

A new solar cell configuration developed by engineers at the University of New South Wales in Sydney has pushed sunlight-to-electricity conversion efficiency to 34.5 percent - establishing a new world record for unfocussed sunlight and nudging closer to the theoretical limits for such a device.

The record was set by Mark Keevers and Martin Green, senior research fellow and director, respectively, of UNSW's Australian Centre for Advanced Photovoltaics, using a 28 cm2 four-junction mini-module - embedded in a prism - that extracts the maximum energy from sunlight.

The record-setting UNSW mini-module combines a silicon cell on one face of a glass prism, with a triple-junction solar cell on the other.

The triple-junction cell targets discrete bands of the incoming sunlight, using a combination of three layers: InGaP; InGaAs; and germanium. As sunlight passes through each layer, energy is extracted by each junction at its most efficient wavelength, while the unused part of the light passes through to the next layer, and so on.

Some of the infrared band of incoming sunlight, unused by the triple-junction cell, is filtered out and bounced onto the silicon cell, thereby extracting just about all of the energy from each beam of sunlight hitting the mini-module.

The new UNSW result, confirmed by the US National Renewable Energy Laboratory, is almost 44 percent better than the previous record - made by Alta Devices of the USA, which reached 24 percent efficiency, but over a larger surface area of 800cm2.

"This encouraging result shows that there are still advances to come in photovoltaics research to make solar cells even more efficient," said Keevers. "Extracting more energy from every beam of sunlight is critical to reducing the cost of electricity generated by solar cells as it lowers the investment needed, and delivering payback faster."

The result was obtained by the same UNSW team that set a world record in 2014, achieving an electricity conversion rate of over 40 percent by using mirrors to concentrate the light - a technique known as CPV (concentrator photovoltaics) - and then similarly splitting out various wavelengths. The new result, however, was achieved using normal sunlight with no concentrators.

"What's remarkable is that this level of efficiency had not been expected for many years," said Green, a pioneer who has led the field for much of his 40 years at UNSW. "

A recent study by Germany's Agora Energiewende think tank set an aggressive target of 35 percent efficiency by 2050 for a module that uses unconcentrated sunlight, such as the standard ones on family homes.

"So things are moving faster in solar cell efficiency than many experts expected, and that's good news for solar energy," he added. "But we must maintain the pace of photovoltaic research in Australia to ensure that we not only build on such tremendous results, but continue to bring benefits back to society."

Australia's research in photovoltaics has already generated flow-on benefits of more than $8 billion to the country, Green said. Gains in efficiency alone, made possible by UNSW's PERC cells, are forecast to save $750 million in domestic electricity generation in the next decade. PERC cells were invented at UNSW and are now becoming the commercial standard globally.

The 34.5 percent result with the 28 cm2 mini-module is already a world record, but scaling it up to a larger 800cm2 - thereby leaping beyond Alta Devices' 24 percent - is well within reach.

"There'll be some marginal loss from interconnection in the scale-up, but we are so far ahead that it's entirely feasible," Keevers said. The theoretical limit for such a four-junction device is thought to be 53 percent, which puts the UNSW result two-thirds of the way there.

Multi-junction solar cells of this type are unlikely to find their way onto the rooftops of homes and offices soon, as they require more effort to manufacture and therefore cost more than standard crystalline silicon cells with a single junction. But the UNSW team is working on new techniques to reduce the manufacturing complexity, and create cheaper multi-junction cells.

However, the spectrum-splitting approach is perfect for solar towers, like those being developed by Australia's RayGen, which use mirrors to concentrate sunlight which is then converted directly into electricity.

The research was funded by the Australian Renewable Energy Agency; and UNSW, in partnership with RayGen Resources, an Australian developer of PV power tower technology; Trina Solar, a PV module manufacturer; and the US National Renewable Energy Laboratory. 

Schletter Group: 48 MWp Project in Italy
ENCAVIS Acquires Two More Solar Parks In Spain and Surpasses The Planned Expansion
Maximum profitability with KACO advanced technology for complex solar roofs
Enviromena wins contract to re-power three major solar farms ahead of the summer energy peak
New Swansea University Collaboration to Support Sustainable, Locally Manufactured Solar PV
New Swansea University Collaboration to Support Sustainable, Locally Manufactured Solar PV
Next2Sun Builds World's Largest Vertical PV Plant at Frankfurt Airport
DNV Publishes Bankability Study of Solcast Satellite Irradiance Data
Steel company SSAB switches to fossil-free energy in Italy with PV solution from Solnet
janom Investments enters the Croatian solar energy industry by investing in a 30 MW power plant project
Trina Solar Vertex S+ 505W n-type dual-glass modules enter mass production
BayWa r.e. and 3E sign partnership agreement for monitoring & analytics of global PV portfolio
Accelerating Spain's Energy Transformation: LONGi to supply Naturgy with 1 million modules in new deal
NTR announces corporate PPA with Almac Group to buy energy from Murley Wind Farm, Northern Ireland
Oxford PV sets new solar panel efficiency world record
Order Intake for the Construction of Wind Turbines in Turkey
Trilantic Europe acquires stake in AEROCOMPACT Group
Octopus Energy makes solar farm debut in Germany
Austria-based KOGA Energy, a solar EPC solutions provider, has kicked off.
Exus to acquire 625MW New Mexico solar portfolio
Capcora Accompanies SUSI Partners In Raising Senior Debt For a Polish Renewables Portfolio
Qualitas Energy acquires a 96 MW wind energy project pipeline in Germany
Nordex Group receives orders from the UK for approx. 150 MW
Trina Solar gains EPD certification from UL Solutions and EPDItaly for industry leading modules
Mandarin Oriental Hyde Park, London instals innovative solar tech to decarbonise heating
Efficiency First: The Road to Electrification
SCHLETTER Supplies Austria's Largest PV Roof System
E.ON partners with UK renewable heat innovator Naked Energy
Sonnedix signs innovative EUR500 million loan facility to finance construction of its renewable electricity pipeline in Europe and UK
Construction begins on Glennmont and Ørsted’s Borkum Riffgrund 3 offshore wind farm in Germany
ABB shores up reliable power supply at Southeast Asia’s largest floating solar plant
Sonnedix starts construction of 300MW UK solar PV portfolio

×
Search the news archive

To close this popup you can press escape or click the close icon.
Logo
×
Logo
×
Register - Step 1

You may choose to subscribe to the Solar + Power Magazine, the Solar + Power Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in: