We’ve been working with two scientists at the top of the photovoltaics (PV) field – Professor Anders Hagfeldt and Professor Sten-Eric Lindquist.
Both scientists are from Sweden and have travelled to the CSIRO Energy Centre in Newcastle to check out our facilities and work with our photovoltaics team…whilst also enjoying summer in the southern hemisphere.
Not only does he play some mean drums in a band called ‘Fat Cotton‘ but Professor Hegfeldt really knows his dye-sensitised solar cells. He’s one of the top 50 scientists in his field! (Watch our short video on the production of dye-sensitised solar cells).
Professor Sten-Eric Lindquist, from Uppsala University, is working with us in our labs, giving us the benefit of his considerable experience in photovoltaics. Professor Lindquist has been examining the properties of semi-conducting photovoltaic materials.
In a neat twist Professor Lindquist was Professor Hagfeldt’s university supervisor (*cough* some 20 years ago).
Our photovoltaics researchers at the Newcastle Energy Centre like to get right into the action when they’re in the lab.
Meet Kenrick Anderson, a photovoltaics experimental scientist. He gets to do fun science things – like monitoring how clean the lab is and filling out forms… no, I mean cool stuff like fabricating new solar cells and testing and comparing how they perform in the sunlight or indoors using a solar simulator.
Want to know more about ‘simulated sunlight’ and what we can do with it? Well, read on. Kenrick has given us his down-to-earth explanation of how one of our measurement tools – a monochromator – helps us understand how solar cells respond to sunlight.
Sunlight contains many different wavelengths of light – it’s a broad spectrum, polychromatic light source. Different types of solar cell respond to different parts of the solar spectrum. To compare these different cells we use monochromatic light – light of a single wavelength– as a means of seeing how a solar cell performs at a particular wavelength. For instance if we take just the light that we can see with our eyes, the wavelengths of visible light start at 400 nanometres and extend out to 720 nanometres.
Do you remember the spectrum by the following acronym?
ROYGBIV (Red Orange Yellow Green Blue Indigo Violet)
Actually, this is in reverse order as red light stops at 720 nanometres and violet starts at 400 nanometres. In nature we see white light being split into the spectrum. Have you noticed the reflection of light as it bounces off water droplets which produces rainbows, or in the interference patterns of an oil slick on water? To reproduce these effects in the laboratory we use a monochromator, like the one pictured below:
A monochromator works using a diffraction grating – a special surface with a series of very fine grooves (about 1000 parallel grooves every millimetre!). When light reflects off the surface the grooves cause the colours to separate out. If you turn a CD over you can see this effect for yourself: a rainbow-like spectrum of colours will be reflected off the disk – it’s a diffraction grating in real life using the even grooves of the CD. Similar surfaces are used within a monochromator to split the light. By changing the angle of the diffraction grating we can choose the wavelength coming from the monochromator. Fortunately, our system is computer controlled and all we need to do is type a number in and out comes the wavelength we are interested in. Job done!
Watch the short movie below showing the monochromator sweeping through the spectrum from 350 nm (in the UV part of the spectrum, just beyond violet) to 750 nm (in the infrared part of the spectrum, just beyond red).
Krishna Feron from our Photovoltaics Group recently attended the annual conference of the CSIRO Computational & Simulation Sciences Transformational Capability Platform and took out the prize for the best poster presentation! Krishna’s project uses a supercomputer to simulate the physical processes that make an organic solar cell work, from the absorption of sunlight through to the collection of electricity. Organic solar cells are an exciting new technology that will hopefully allow solar cells to be mass produced for the cost of printing a newspaper.
Krishna says CSIRO’s GPU cluster is already one of the most energy-efficient supercomputers in the world‡ and its application to solar cell research is now making it even more ‘green’!
‡CSIRO’s Supermicro Xeon Cluster is ranked 15 on The Green500 list – a ranking of the world’s fastest and most powerful supercomputers by energy efficiency (June 2011 rankings)
For more information see: The Green500 List
On Wednesday 27 July CSIRO received great news – funding from the Australian Solar Institute (ASI) and the Victorian Department of Primary Industry (DPI) to develop the next generation materials that will feed into the large scale printing trials being conducted by the Victorian Organic Solar Cell (VICOSC) Consortium. VICOSC consists of key researchers from Melbourne University, Monash University and CSIRO, together with industrial partners BlueScope Steel, Innovia Films (UK) and Robert Bosch SEA.
CSIRO, through its Future Manufacturing Flagship, is a foundation partner in the VICOSC Consortium which was awarded $1.7m from both the Australian Solar Institute (ASI) and the Victorian Department of Primary Industry (DPI) under their respective renewable energy programs. Matched by contributions from the Consortium members, the project is worth a total of $7 million over 3 years.
At the announcement event working demonstrations of solar cells printed on flexible plastic were on display. The solar panels were printed using laboratory based reel-to-reel printing processes located at CSIRO’s Clayton Flexible Electronics Labs.
Read the Minister Ferguson’s media release here: http://minister.ret.gov.au/MediaCentre/MediaReleases/Pages/solar-manufacturing.aspx
Did you know that at present Australia’s largest system of solar photovoltaic panels (at the University of Queensland) is rated at 1.2 megawatts? Sound like a lot? Well, compare that with the world’s largest system (in Sarnia, Ontario), rated at 80 megawatts.
Now, finally, Australia is playing with the big boys. As a result of the Federal Government ‘Solar Flagships’ program, Innovation Minister Senator Kim Carr has announced funding for a system rated at a whopping 150 megawatts!
With a group of other top researchers, CSIRO will lead R&D worth A$66.5 million at a proposed Solar Farm in Moree, a regional farming community in northwest New South Wales.
It’s all part of an Australian Government initiative to support the construction of large-scale, grid-connected solar power stations in Australia, using solar thermal and photovoltaic technologies: the A$1.5 billion Solar Flagships program. The Moree Solar Farm is a $925 million project involving BP Solar, Fotowatio Renewable Ventures (FRV) and Pacific Hydro and a consortium of researchers from CSIRO, The University of New South Wales, The University of Newcastle and Hunter TAFE.
I can hear people already saying ‘how big is that?’ Well, when fully operational the Solar Farm will comprise around 650 000 photovoltaic panels and produce enough power for around 45 000 households (a city roughly the size of Darwin!), leading to an annual displacement of around 400 000 tonnes of CO2 through generation of renewable electricity.
For more on the project go to: http://www.csiro.au/science/Moree-solar-farm.html
There has been some buzz in the media recently about our printable solar cell work, particularly a joint project between Dr Jacek Jasieniak from CSIRO’s Future Manufacturing Flagship and Brandon MacDonald a PhD student he is co-supervising with Prof Paul Mulvaney (University of Melbourne).
Brandon and Jacek have done some really neat work based on nanomaterials. Their patented technology uses inks containing tiny, semiconducting nanocrystals, which can be printed directly onto a variety of surfaces. By choosing the right combination of ink and surface it is possible to make solar cells with very efficient use of materials and low embodied energy:
We’ve got some talent: Dr Jacek Jasieniak has recently won a 2011 Fulbright scholarship to work in the US for 12 months with Nobel Prize winner Prof Alan Heeger, on next-generation flexible lighting systems:
Brandon is one of 16 early-career scientists presenting their research to the public for the first time thanks to Fresh Science, a national program sponsored by the Australian Government. For his work Brandon has received the 2010/11 DuPont Young Innovator’s Award and has had his work published in the journal Nano Letters. Check out more on Brandon and his work at: