Acceptance speech – Martin Green

I think the technological challenge can be met. It remains to be seen whether the political and organisational challenges involved in recognising and addressing the need to change from the status quo can also...

Mr Speaker, your Excellencies, dear Friends,

It is a great honour for me to receive this award, particularly together with the other individuals and organisations with such honourable and resolute achievements.

My award is for my work in photovoltaic solar energy or, more simply, in improving methods for making electricity from sunlight using devices known as solar cells.

I think most informed people are aware of the huge amounts of energy required to support modern life. I think these days most also recognise how our dependence upon these huge amounts of energy has created problems in the past and present, with the very disturbing potential to create problems well and truly beyond our control in the future.

Given the huge amounts of energy involved, I think it will come as a surprise to most when I tell you that, in just three days, the earth receives more energy from the sun than from all the fuel burned by humans, not over the last year, but over the whole of human history. Australia, where I come from, has hundreds of years of coal reserves. However, just three weeks of sunshine offsets all the world’s known fossil fuel reserves.

To me, this puts the issue of the world’s energy supply into a completely different perspective. The sun still provides almost all the energy to support human life, just as it did 500, 5,000 or even 50,000 years ago. The difference is that the extra amount of energy that we now use is not generated very sensible. It is causing problems that are disproportionately large compared to the amount involved.

To me, the path to a sustainable energy future seems very obvious. We have to find a way to tap into a very small fraction of the sun’s energy to convert it to a form suitable for supplying what are in fact the relatively small additional energy requirements of modern life. Electricity is one such suitable form.

This challenge seems well within the scope of human technological capabilities, almost trivial compared to other approaches that have received more support, such as nuclear fusion. I think the technological challenge definitely can be met and, as I will mention later, may have already been largely met. It remains to be seen whether the political and organisational challenges involved in recognising and addressing the need to change from the status quo can also be met on a reasonable timescale.

On a personal note, my own involvement in photovoltaic began some thirty years ago. I had become interested in microelectronics during my final years as an undergraduate student. Although microelectronics was clearly an exciting field to be working in, I then became increasingly disillusioned with prospects of spending my working life in this area, which I characterised something like “building a better television set” at the time. I was thinking of a major change in career, when my postgraduate research led me to photovoltaic.

Here was an area where I could use the microelectronics skills I had developed while meeting my need to feel that I was using these skills to do something fundamentally useful.

On returning to Australia in the mid-1970s after my doctorate, I set up a small research team to work on improving solar cell performance.  At first we struggled to make much impact. However, by the early 1980s, our work was starting to receive international attention.

In 1983, we set our first world-record for improved silicon solar cell performance. This was quite a surprising achievement for a small research team from Australia, given that our competitors were much better funded within the research laboratories of major microelectronics companies and government agencies in the USA, Japan and Europe.

Our lead quickly increased. In 1985, we broke the solar equivalent of the “four minute mile”, the first silicon cell to convert 20% of the solar input to electricity, a value long regarded as a practical limit. We are now up to 25%.

We also developed a commercial version of our improved cells which, largely through the efforts of our first licensee, BP Solar, has become one of the most successfully commercialised new technologies since then. BP Solar, now one of the largest players in the solar cell industry, plans to sell over Euro 1 billion of these by 2010.

Our international leadership allowed my group to survive the 1980s almost intact. The period spanning the US Reagan Administration was very bleak for photovoltaic, with many other groups working in the area having to disband. As we were one of the few groups left standing, we felt this increased our responsibility to concentrate our efforts on the most important problems facing photovoltaic.

Solar cells are made using silicon wafers, the same thin discs of silicon as used in microelectronics. We saw the main challenge facing the area was to find a way of getting rid of these relatively expensive wafers, by depositing the photoactive material directly as a thin layer onto a supporting glass superstrate. Although several approaches had been developed for doing this, we considered these marginal since none involved the same high quality, reliable material as used in wafers.

It has become clear over recent years that our work with this thin ‘silicon-on-glass’ technology has also been successful. A company, Pacific Solar that I helped set up in Sydney to commercialise this approach, has recently demonstrated pilot line production with this approach, with good efficiencies and yields and with projected costs significantly lower than with the standard wafer-based approach.

What needs to be done to accelerate the development of photovoltaic and get it to the stage where it can reduce our dependence upon the less desirable present energy generation options?

The strategy that is appearing to be quite effective might be described as “market pull”. By subsidising the installation of solar-electric systems on the roofs of private homes, various local and federal governments around the world have helped stimulate the market for photovoltaic, growing at 30-40% per year over each of the past six years.

This buoyant market has encouraged manufacturers to invest in new facilities and manufacturing processes that are helping to drive prices down. We are also hoping that it makes it easier to commercialise new technology, particularly our new thin silicon-on-glass approach.

The German politician, Dr. Hermann Scheer, recipient of the 1999 Right Livelihood Award and Time Magazine’s “Green Hero of the 20th Century” has been the driving force behind the legislation that underpins the German program in this area. The electoral success of his party in September makes it possible that the present program covering 100,000 roofs in Germany will be extended to 1 million such systems. Other European countries with similar programs include the UK, the Netherlands, Switzerland, France, Italy, Spain and Portugal. Not all of these, you might have noted, are renowned for their sunshine. Outside Europe, Japan is the leader in this area. Australia and a number of states in the United States also have similar programs. The diversity of governments with such programs provides some protection for the industry against the impact of any single program ceasing.

This seems to me to be a relatively painless and effective way of promoting the development of this industry and of ensuring the international competitiveness of local companies involved in this area. By driving photovoltaic prices down through such programs, the cells will be able to compete with conventional sources more quickly than otherwise possible. Unlike conventional sources, they are also suitable for supplying electricity to that third of the world?s population that still has no access to it.

In conclusion, I would like to thank all those that have contributed to my group’s work over the thirty year period briefly alluded to. I would especially like to thank my wife, Judy Green, for her support over this period and for encouraging me to push my work to its limits.

Professor Martin Green
Centre for Photovoltaic Engineering
Electrical Engineering Building
The University of New South Wales
Sydney NSW 2052