There is so much that goes on in the world of PV and scientific discovery, that it’s hard to keep up! Below is a sample of latest news, as curated by the Organising Committee, on the latest happenings in PV.
High transparency solar panels for greenhouses - 19 November 2021
Lithuanian company Solitek are making solar panels that are designed for the roofs of greenhouses. The panels transmit 40% of the visible light, while at the same time producing 235 W. Changing the amount of light entering a greenhouse can modulate the growing conditions for plants. In some climates, the shade from the panels can improve the yield of plant growth and reduce the amount of water needed.
Read more at PV Magazine
Solar PV used to offset emissions and save costs in airports - 17 November 2021
Airports around Australia are looking into ways to use solar panels to decarbonise their operations. Melbourne airport has the largest solar capacity in Australia, with just over 14 MW installed. Brisbane airport reported that the installation of a 6 MW solar system in 2019 has allowed them to defer $20 to $50 million, due to the peak load management provided by solar.
Read more at PV Magazine
South Australian grid experiences 'negative demand' due to strong rooftop solar generation - 4 November 2021
For four days in October, the South Australian electricity grid experienced ‘negative demand’ events during the day, due to the large amount of rooftop solar in the state. This is indicative of a fundamental change taking place in electricity grids, from the old, centralised model to a two-way network. One solution to the generation of excess electricity could be an increased uptake of electric vehicles, which could use this electricity to charge.
Read more at Renew Economy
LONGi breaks the 26% efficiency barrier for industrial silicon heterojunction cells - 29 October 2021
LONGi Solar has announced a new world record efficiency of 26.30% for silicon heterojunction solar (SHJ) cells. This announcement came just days following the previous record efficiency of 25.82%, also held by LONGi. This result represents the highest efficiency for a front-back contacted solar cell, as the world record of 26.7% achieved in 2017 uses an interdigitated back contact (IBC) cell design.
Read more at LONGi Solar
Record high solar PV generation in Australian grid - 6 October 2021
On Wednesday October 6, the amount of solar PV generation in the Australian electricity grid reached 9104 MW, smashing the previous generation record of 8505 MW set in the previous month. This new record represents a 26% increase compared to the highest solar PV generation in October 2020. This is indicative of the rapid growth of the renewable energy contribution to electricity generation in Australia and follows a record combined renewable energy share (including Hydro) of 61.7% observed recently.
Read more at Renew Economy
New study highlights material sustainability issues in PV manufacturing - 27 September 2021
The amount of solar PV manufactured over the next ten years and beyond is expected to rapidly increase to help curb global CO2 emissions. This rapid expansion will require further considerations be given to the consumption of the constituent materials that go into making commercial solar panels. New research from UNSW has shown that the consumption of materials, in particular silver, indium and bismuth, will place limitations on the ability for PV manufacturing to expand at the required rate. The authors also suggest that tandem architectures can help reduce material consumption, as they have lower power losses due to series resistance compared with single junction approaches.
Read more at ‘PV Magazine‘
Heliostats used to shine light on dark urban areas - 17 September 2021
A heliostat uses an array of movable mirrors to redirect the suns’ rays. While typically used in a large solar power plant to concentrate sunlight, this approach is being adapted to the built environment, to help redistribute light to dim urban areas. A new design in Rhodes uses movable mirrors on the roof of a 39-story building to bounce light to an array of reflectors, which then shines the light back to the street. As the buildings in our cities grow taller and taller, this could provide a potential solution to shading.
Read more at ‘ABC News‘
Australian solar company Sundrive breaks world record for commercial size silicon solar cells – 15 September 2021
Australian company Sundrive achieved a world record efficiency of 25.54% for a commercial size silicon solar cell, improving on the previous record of 25.26% held by LONGi. One fundamental difference with previous record cells is that Sundrive are using a technique called ‘copper plating’ to form the metal contacts, as opposed to the traditional screen printing of silver currently used in industry. The predicted rapid expansion of the PV industry over the coming decade has raised concerns over the consumption of silver for metal contacts, which has made the switch to copper contacts more appealing. This demonstration of a world record cell efficiency using copper represents a major breakthrough for the technology.
Read more at ‘Renew Economy‘
Study finds green roofs make solar panels more efficient - 24 August 2021
Two identical office buildings side by side in Sydney’s Barangaroo provided a perfect opportunity for solar energy researchers to test a long-held hunch.
The answer, as it turned out, was yes.
The study was led by Peter Irga from the University of Technology Sydney and funded by the City of Sydney Council.
“For the first time we had the opportunity to compare these two buildings against each other,” Dr Irga said.
Read more at ‘ABC News‘
UNSW Solar Pioneer Wins Major International Engineering Award - 22 June 2021
UNSW Engineering Professor Thorsten Trupke has won the internationally coveted IEEE William Cherry Award. The award recognises outstanding contributions to photovoltaic science and technology, by an individual who has devoted part of their professional life to the cause.
The award is named in honour of the late William R. Cherry, a founder of the photovoltaic community and pioneer of using photovoltaic systems for terrestrial applications.
Read more at ‘UNSW Newsroom‘
LONGI Breaks 3 World Records For Industrial Silicon Solar Cells - 2 June 2021
The PV industry continuous to push the efficiency of industrial silicon solar cells. LONGI was able to improve the world-record efficiency of three types of solar cells with at least one passivating contacts. They improved the efficiency of both n-type and p-type solar cells with a TOPCon electron contact to 25.21% and 25.02%, respectively. In addition, they demonstrated a 25.26% efficiency for a silicon heterojunction solar cell. These are remarkable efficiencies considering that these were produced on full industrial sized silicon wafers using pilot production equipment. Both TOPCon and silicon heterojunction solar cells are intensively investigated for near-future high-volume manufacturing.
Read more at ‘LONGI Solar‘
‘Insanely cheap energy’: how solar power continues to shock the world - 25 April 2021
UNSW Scientia Professor Martin Green describes how photovoltaic solar power went from being outrageously expensive to “insanely cheap”. His team at UNSW laid many of the foundations for this incredible cost reduction that has been achieved through international collaboration and partnership. The PVSEC conferences have served as an important forum for this research witnessing and fitting that in 2021, the conference returns to Sydney where the latest scientific research and industrial developments will be announced. Professor Green will deliver the opening keynote address at PVSEC-31, 11am December 13th 2021.
Read more at ‘The Guardian‘
French photovoltaic greenhouse delivers 3.1 GWh and 4 tons/hectare of asparagus in one year - 1 April 2021
In April 2017, French renewable energy developer Tenergie commissioned its first photovoltaic greenhouse based on its proprietary technology Tenairlux, in Mallemort, in the Bouches-du-Rhône region of southern France. The plant was built with 265 W panels and has an installed power of 2.1 MW.
“Four years after the commissioning of this 33,000m² greenhouse, our feedback is positive, with a yield of four tons/hectare for this first year of growing green asparagus from Provence, after a period of diversified cultivation including zucchini, turnips, [and] sweet potatoes during the first three years and a production of 3.1 GWh of green electricity, which is the equivalent of the consumption of 700 households, excluding heating,” the company wrote in a detailed report. For 2022, the expected agricultural yield is expected to increase to nine tons/hectare.
Read more at ‘PV Magazine‘
New 2J Tandem Solar Cell World Record Efficiency Of 32.9% - 30 March 2021
The QPV Group at UNSW in partnership with researchers at the National Renewable Energy Laboratory (NREL) in the USA have set a new world record of 32.9% marking the highest double-junction solar cell efficiency achieved to date under AM1.5G. One novel aspect is the bottom sub-cell is formed from an artifical semiconductor composed of a strain-balanced stack of GaAsP/InGaAs quantum wells yjay gives rise to properties not found in natural semiconductor alloys. Quantum wells have been used extensibvely in semiconductor lasers and LEDs but this is the first time that this type of artifiical semiconductor has resulted in a more efficient tandem solar cell.
Read more about this result:
- Research paper published in Advanced Energy Materials
- News item published by NREL Quantum Wells Enable Record-Efficiency Two-Junction Solar Cell
- Article in PV Magazine New approach to III-V tandems sets 32.9% efficiency record
- Article in Renew Economy Australian researchers help set new records for ultra-high efficiency solar cells
- Article in Green Review Quantum wells enable record-efficiency two-junction solar cell
New World Record in Perovskite Solar Cell Efficiency - 11 March 2021
Perovskite solar cells have seen a rapid rise in recent years due to their potential for low-cost processing and high power conversion efficiencies. Passivation of perovskite cells, especially at the perovskite-charge transport layer interfaces, plays a key role in reducing nonradiative recombination and to achieve high open-circuit voltages. Polymer passivation layers are typically used for this purpose; however, such layers are poor conductors, leading to a trade-off between passivation quality (voltage) and series resistance (fill factor).
A nanopatterned electron transport layer consisting of a sparse array of TiO2 nanorods was developed that overcomes this trade-off by forming nanoscale localized charge transport pathways through a passivated interface, thereby providing both effective passivation and excellent charge extraction.
A certified power conversion efficiency of 21.6% was achieved for a 1-square-centimetre cell with a FF of 0.839. Encapsulated cells retained >91% of their initial efficiency after 1000 hours of damp heat exposure.
. J. Peng, D. Walter, Y. Ren, M. Tebyetekerwa, Y. Wu, T. Duong, Q. Lin, J. Li, T. Lu, M. A. Mahmud, O. L. C. Lem, S. Zhao, W. Liu, Y. Liu, H. Shen, L. Li, F. Kremer, H. T. Nguyen, D.-Y. Choi, K. J. Weber, K. R. Catchpole and T. P. White, “Nanoscale localized contacts for high fill factors in polymer-passivated perovskite solar cells”, Science, 2021, 371, 390-395.
Honorary Chair of the PVSEC-31 Scientia Professor Martin Green Awarded the Prestigious 2021 Japan Prize - 8 February 2021
Australia leading the Global Energy Transition: 100% of South Australia powered by Photovoltaics - 19 November 2020
Australia achieved another impressive milestone in the transition to a low carbon future when South Australia was fully powered by Photovoltaics for 1 hour on Sunday, 11 October 2020. This is a unique achievement globally as South Australia has an area of close to 1 million km2 which is one and a half times bigger than Texas and five times the United Kingdom! The photovoltaic energy was mostly supplied by rooftop solar at 77%, whereas the remainder was provided by large-scale PV. The actual renewable energy production was well above 100%, and the remainder was either stored in batteries or exported to Victoria.
Potential Light-Induced Degradation in Industrial Silicon Heterojunction Solar Cells? - 22 September 2020
The long-term stability of solar cells under illumination is of key importance for their application. Generally, it assumed that solar cells using n-type silicon do not suffer from light-induced degradation due to the absence of significant amounts of boron in the bulk of the material, i.e., making these solar cells immune to the boron-oxygen defect. However, Madumelu and co-workers  recently reported that they observed a significant amount of degradation after light soaking. These measurements were done at temperatures of 160 oC to accelerate the testing.
As can be seen in the figure below, a significant reduction in solar cell efficiency up to 1 % absolute was found when the solar cells were illuminated, whereas an improvement was observed when the solar cells were kept in the dark. The authors related the change in solar cell performance to changes in the amorphous silicon heterojunction contact. It should be noted that amorphous silicon is stable at the temperatures used in this work and that similar illuminated anneals do not seem to affect other types of solar cells such as PERC.
Further work is needed to identify the exact nature of this defect and to investigate if this can also affect photovoltaic modules with silicon heterojunction cells in the field which would typically operate at significantly lower temperatures.
Solar conversion efficiency of individual cells as a function of time after either dark-annealing (DA) or light-soaking at 1 kWm-2 illumination intensity at a temperature of 160 ◦C. A reference cell that was stored at room temperature was included to test the repeatability of the measurement. All I-V measurements were conducted ex-situ under standard testing conditions.
 C. Madumelu, B. Wright, A. Soeriyadi, M. Wright, D. Chen, B. Hoex, and B. Hallam, “Investigation of light-induced degradation in N-Type silicon heterojunction solar cells during illuminated annealing at elevated temperatures,” Solar Energy Materials and Solar Cells, vol. 218, p. 110752, 2020
New Candidate for Single Junction and Silicon-based Tandem Solar Cells Reaches Landmark 10% Efficiency - 2 September 2020
The photovoltaic field is currently working hard to identify the ideal candidate for a silicon-based tandem solar cell. From a material perspective, an ideal top cell has a bandgap of ~1.6 eV, high absorption coefficient, and consists of only earth abundant and ecofriendly materials. In addition, it should also be easy to manufacture, compatible with silicon, and have a long-term stable performance.
Solar cells based on antimony sulphide/selenide have all these desired properties, however, their solar cell performance was still too low with record efficiencies around the 7% range. On 20 July 2020, a team of researchers from China and Australia have reported the first antinomy sulphide/selenide with an efficiency above 10% in the journal Nature Energy .
They achieved this landmark result by optimising the deposition and post-processing step of the absorber material resulting in a significant improvement in its morphology, grain size, and a reduction in the defect density in the film. This result illustrates the potential for this material as a candidate for future silicon-based tandem solar cells.
 R. Tang, X. Wang, W. Lian, J. Huang, Q. Wei, M. Huang, Y. Yin, C. Jiang, S. Yang, G. Xing, S. Chen, C. Zhu, X. Hao, M. A. Green, and T. Chen, “Hydrothermal deposition of antimony selenosulfide thin films enables solar cells with 10% efficiency,” Nature Energy, 5, pages587–595(2020).