Dye Solar Cell (an interview on ABC Television News, 18 Nov 2004)
Dye Solar Cell
(an interview on 18 November 2004 of ABC Television News with Gavin & Sylvia Tulloch)
Reporter: Christopher Zinn
Producer: Paul Faint
Researcher: Maria Ceballos-Wallis
Source: http://www.abc.net.au/catalyst/stories/s1241478.htm
Photovoltaic solar cells were invented over 50 years ago and are now a well-accepted technology. But they’re still quite expensive to make because they’re made from silicon crystal. But that could be about to change. An Australian husband and wife team have been developing a completely new type of solar cell… that doesn’t use silicon at all.
TranscriptTranscript
Narration
Mankind has long dreamt of harnessing the power of the sun. And while we've come up with the silicon solar cell... we haven't yet been able to mimic natures' own solar cell... the humble leaf...
The chlorophyll in a leaf absorbs sunlight... which the plant then turns into energy to grow... And as every schoolkid should know... it's called photosynthesis.
Christopher Zinn, reporter
Its one of the most basic, elegant and important of all natural cycles-and for years scientists have been trying to replicate it in a solar cell... but needless to say it hasn't been simple. Because whereas the design life of a leaf has to be just for one season for a photovoltaic it has to be more like 50 years.
Narration
But that hasn't deterred two Australian scientists from taking on the challenge.
Christopher Zinn, reporter
So is this a perfect version of what you are trying to achieve?
Gavin Tulloch
Yes it is. It's actually more perfect than what we've achieved because it's had much more practice. It's had millions of years to perfect itself and we've had 10.
Narration
Ten years ago, Gavin and Sylvia Tulloch took a huge gamble and invested everything on a technology many people said would never work.
In 1991, a Swiss scientist named Michael Graetzel claimed to have unlocked the secret of 'artificial photosynthesis'.
The Australian government wanted it checked out and that's when Gavin and Sylvia's lives were changed forever.
Sylvia Tulloch
That's right they said to us, we've identified this invention of artificial photosynthesis in Switzerland and we think it might be good to bring it to Australia. And we said, this can't work.
Gavin Tulloch
And unfortunately Michael Graetzel got a sample out and it worked. And so I said there's a possibility we could be wrong here.
Narration
Graetzel's solar cell was made from a semi-conductor called titania... and a dye, which absorbed sunlight, just like the chlorophyll in a leaf.
Gavin Tulloch
It's long been known that if you put a dye on to titania you would be able to get the artificial photosynthesis. That wasn't new. But you couldn't get any current out of it. It was a useless device.
Narration
But Graetzel had found a way to make it work...
Instead of using solid titania he used a paste containing microscopic, nano-particles of it.
When these nano-particles were coated in dye... the surface area able to absorb light increased by 1000 times... it became a sort of 'light sponge'.
Now, for the first time, 'artificial photosynthesis' was able to generate useable electrical energy.
Gavin and Sylvia were hooked.
They could see the enormous potential of the device... if only it could be taken out of the lab and turned into something you could use.
So they took the plunge... sold up in the big smoke... and set up shop amongst the car yards and panel beaters of rural Queanbeyan.
Sylvia Tulloch
Maybe there are some people who don't think things can be done here. So there's a lot of proving to do.
Christopher Zinn, reporter
So you mean if you're in a hi-tech campus in California it might have been easier?
Gavin Tulloch
Oh Yes. Yes if we were an American company or in the right location, yes that would have been much easier.
Narration
While Graetzel had invented the leaf, if you like... Gavin and Sylvia were trying to build a tree.
First, they had to get more power out of the cell... this meant getting the composition of the titania paste just right... and finding a dye that absorbed the maximum amount of sunlight.
Gavin Tulloch
Oh it could be any colour. This is just the most mature dye. This is the best one. Fortunately it's also a lovely colour, a warm colour for buildings.
Narration
Next, they had to make sure the cells were stable and reliable.
Christopher Zinn, reporter
And what sort of light are you shining on it?
Gavin Tulloch
We're shining an artificial sun. It's a third of a sun.
Narration
Finally, they've had to design the manufacturing process from scratch and build much of the machinery by hand...
Now, after ten years of hard yakka and twenty million dollars of public and private investment... they've produced the world's first 'dye solar cell' building panel.
The Tulloch's claim the DSC's will be cheaper than conventional silicon cells...
They're translucent, so they can be used as energy gathering windows... and they work even in shadowed or low light conditions.
But just because you've delivered a new product doesn't guarantee success...
Gavin Tulloch
Oh technologically yes, technologically it arrived a while ago. We're very happy with the product. Promotionally it's a different kettle of fish.
Sylvia Tulloch
That's right. It's commercially we need to scale up manufacturing. We need to drive the cost down through volume and that means we need to attract the appropriate funds to do that. And we honestly haven't succeeded in that yet.
Narration
It's a big ask. The established technology of silicon solar cells accounts for more than 95% of the market. Gavin and Sylvia desperately needed an opportunity to demonstrate that their DSC's worked in the real world...
And then their big break finally came... the CSIRO commissioned a 200sq metre array of DSC's to be featured in their high-tech Energy Centre in Newcastle.
Sylvia Tulloch
Well what we're seeing is the world's first array of dye solar cells. You can see it's designed to look something like a modern stained glass window but at the same time of course its producing electricity.
Narration
At least that was the plan... but there was a problem... it didn't work.
Sylvia says the malfunction was due to some of the panels being shorted out during delivery.
But whatever the cause... the contractual row means it still isn't fixed... and the array is generating rather more raised eyebrows than volts.
Christopher Zinn, reporter
There have been stumbling blocks. I mean Newcastle must have been a major disappointment?
Sylvia Tulloch
Of course, yes. But you take breath and you say in a new technology with a new demonstration of it, it's always going to take a while to get it right. We'll get it right eventually.
Narration
Now with the stakes higher than ever... they've been given a second chance to 'get it right'.
This concept design featuring a unique Dye Solar Cell skylight is about to become a reality. It's one of 6 homes being built for 'The House of the Future' exhibition which is touring Australia.
It's a great showcase opportunity... but another failure could damage the project.
Sylvia doesn't want to leave anything to chance.
Sylvia Tulloch
100% working which is always a relief.
Narration
Finally the cells are up and working... but due to delays with construction, The House of the Future remains just that... and still isn't completed. As the Tulloch's now know too well... turning a dream into reality is never easy...
Sylvia Tulloch
You have to be willing to take enormous personal risk. It's not for the weak-hearted.
Gavin Tulloch
It's not for those who are prepared to give up when things don't work. Technologically, commercially, you just battle on.
Narration
Let's hope the battle doesn't rage for too long... and the 'artificial leaf' soon sees the light of day.