Big Ideas

The federal government has committed us to reducing our greenhouse emissions by 60% over the next 40 years. Meanwhile the demand for electricity continues to head north. Maybe the answer will come from on high, beneath our feet, or it's blowing in the wind. Join us for the first of two panel discussions on tackling that target. Today proponents of renewable energy put forward their best, new technologies.

This is edited broadcast of a public forum held on the 21st of April 2008 as part of the free Melbourne Conversations program. It was organised by the City of Melbourne, in collaboration with the Australian & New Zealand Association for the Advancement of Science and the Australian Academy of Technological Sciences and Engineering and kindly supported by Future Leaders.

Transcript

Peter Mares: Hello, I'm Peter Mares, welcome to Big Ideas on ABC Radio National. And the first of two programs about energy and climate change, science and technology for Australia's future.

This program recorded at a recent public forum in Melbourne, looks at the potential contribution renewable energies might make to help Australia reduce its greenhouse gas emissions. Technologies like solar, geo-thermal, wind, wave and tidal power.

Three experts will impress you with the latest developments in their fields. And then next week at this time, we'll look at non-renewable energy sources, particularly coal and nuclear power. What role could they play in helping Australia to address climate change issues?

Both this week and next, renowned climate scientist Dr Graeme Pearman, former Head of Atmospheric Research at the CSIRO, will provide expert comment and analysis on all the presentations.

The forum formed part of the City of Melbourne's free Melbourne Conversations program, and conducted in association with the Australian and New Zealand Association for the Advancement of Science, ANZAS, and the Australian Academy of Technological Sciences and Engineering. The moderator was yours truly.

Peter Mares: We're not here tonight to talk about the science of climate change. The starting point for our conversation is the fact that the Federal government has already committed Australia to reducing greenhouse gas emissions by 60% by 2050. So our question tonight and next week, is how we might best meet that policy target, and provide for Australia's energy needs.

Our first speaker this evening is Professor Andrew Blakers, Director of the Centre for Sustainable Energy Systems at the Australian National University, and a world leader in the development of solar technology. Please welcome Professor Andrew Blakers.

Andrew Blakers: I'd like to start off first with a brief snapshot of what energy sources are available to our species, and they fall into four categories: fossil fuels, that's oil, gas and coal; nuclear; there's a couple in the other categories, that's tidal and geothermal, and you can hear more about geothermal in a little time; and finally, solar.

Solar comes in many different forms, but it can be categorised into two categories: the direct solar resources, where you need to see the disc of the sun to make the thing work; and the indirect sources, where the sun drives some aspect of the weather system for example, so wind, hydro, biomass, and ocean. They're all of course solar energy, but in an indirect form.

So the characteristic of direct solar energy is it's vast, with a resource base hundreds to thousands of times larger than is required to provide all of our power. It's ubiquitous, it's not concentrated like oil is in the Middle East; it's clean; it's inexhaustible until the sun dies; and it's indefinitely sustainable.

So let's have a look at what direct solar can do for you. The first thing of course is to use less energy in the first place, energy conservation. And in many ways, energy conservation is solar energy. If you build a solar-efficient building, then you have solar energy heating the house directly without the need for artificial heating and artificial lighting and the rest. You can also go to active solar energy sources such as a solar water-heater, which you can see on many house roofs but only still a tiny fraction of the total, and there's no reason why solar heaters shouldn't be on every house. Solar air heaters, which can be used to heat the house if you don't happen to have north-facing windows, and you don't want to knock your house down and start again. And then photovoltaics, which are increasingly seen on house roofs around the world, and you can do it on a very small scale, or perhaps quite a large system that would provide substantial amounts of power.

The solar energy for photovoltaics is based on the science of solar cells, which are discs of silicone that allow you to convert light directly into electricity with no moving parts, with an efficiency of between 15% and 25%.

You can use concentrated systems for both thermal and photovoltaic conversion techniques. You can do it on a very large scale in central power systems, where you have long troughs running for kilometres across the desert, directing and focusing sunlight onto a small receiver. You can do dishes, and once again, if you have a large parabolic dish that looks a little bit like a radio telescope, you can extract the solar energy, the concentrated solar energy either using a thermal receiver that's hot, makes steam, which drives a turbine, or by lining the receiver with solar cells that directly convert the sunlight into electricity.

One thing about sunlight is there's an awful lot of it. What you can look at is the 'noon- equivalent sunshine hours per day' that you receive on average, and the worst place in Australia, south-west Tasmania, still receives about 3.5 hour noon equivalent sunshine hours per day, and that's better than most of northern Europe where the solar energy boom is well under way. The best place is up in the north-west of Australia where you can have 6 or more noon equivalent sunshine hours per day.

We can superimpose on a map of Australia, a circle that represents the amount of land required to supply all of the world's electricity and solar power, and that's roughly equal to the area of the State of Victoria. And if we only want to supply all of Australia's electricity from the sun, we need a much smaller area, about the size of the ACT, and in fact the area of roof in Australia is sufficient to provide all of Australia's electricity.

The environmental footprint of solar energy is remarkably small. There's a 100-fold reduction in the amount of mining that you need to do compared with fossil and nuclear, for solar energy utilisation for a given annual energy output. And interestingly, gram for gram, an advanced solar cell will produce as much electricity over its lifetime, as a nuclear fuel rod. A lot has been talked about electricity reliability and baseload, and the alleged advantages of nuclear and fossil fuel in this respect. This is, to put it bluntly, a load of crap.

You can easily have an entirely renewable energy power system, and you do this by having geographical dispersion, so you have collectors for your solar power everywhere, right through the eastern seaboard and in the west. And the chance of a cloud being everywhere is quite low. You have the possibility to shift loads from night to day. At the moment we shift loads from day to night, through off-peak electricity hot water for example. Well we just reverse that process.

Technology diversity is another way in which we'll accomplish this goal. We have photovoltaics, solar thermal, wind, geo thermal, biomass, a whole range of activities, and even some natural gas and even perhaps some coal with capture and storage, if they ever succeed in doing that in a cost-effective way.

Then we have storage, and the simplest way of storing by far is simply pumped hydro. You don't even need a river. For example the Adelaide Hills and the sea: a very small coffer dam up in the Adelaide Hills, you make the seawater go around a circle, and a very small dam, of a couple of square kilometres would be enough to level the entire load for Adelaide.

The important point to make is that storage is not an issue until we get to quite large penetration of the national grid, and we have a lot of time before this will be a really serious issue, you know, 10, 15, 20 years, depending on how fast climate change is addressed. And that gives time for further improvements in storage technology.

The costs of solar power are falling quickly, driven by concern about climate change and we ain't seen nothing yet, as the scale of the industry goes up and up and up, so the costs come down and down.

So we have solutions for everything that we need. For electricity we have photovoltaics and solar-thermal electricity, and of course the other renewables that I mentioned. For heating we have solar heat for efficient buildings and industry, and we can have thermal storage in crushed rock, or phase-change materials or other methods. We have transport, we can shift the energy for transport from oil to electricity and have electric cars if we really want to stick with cars, or electric powered public transport. And of course if you've got water, carbondioxide and solar energy, you can reverse the chemical reaction of combustion, and make any fuel that you like.

And finally, chemicals and metals can be produced using electricity or high temperature heat from solar. We can do the whole job with solar and the allied renewables.

Looking at the industry, the worldwide photovoltaic industry which is the leading solar electricity technology at present is undergoing remarkable growth. The current doubling time for this industry is 20 months, every 20 months we've doubled the industry. The industry is worth about $40 billion last year, and confidently expected to get to $100 billion by about 2010, and then we'll set sail after oil and the defence industries, which is the trillion dollar mark, and I think we'll get there in the late 2020s. This will be a very, very big industry.

Australia has agreed after the last election to a renewable energy target of sixty terawatt hours per year of additional renewable electricity by 2020, and that's about 20% of the projected electricity consumption at that time. And that will entail a $30 billion to $60 billion investment. And this has the potential if it's done right, to seed a major manufacturing industry and if it's done wrong, to seed a major cardboard box opening industry from cleverer countries overseas that get on this industry and go for it.

Australia is at the very last gasp of the time to grab this opportunity and go for it. If we wait too many more years, we will have ceded supremacy to other countries. We have a very narrow skill base brought about by very small investments over the past decade by the previous government, and a major investment in education is needed and a huge increase in R&D is required in order to feed through into those technologies that will make it big on the world market.

We have some renewable energy innovation funding, but look at what the fossil fuel industry gets. Several CSIRO divisions, several co-operative research centres, several other purpose-built institutions. It's just chalk and cheese. There's a very substantial over-emphasis on so-called 'clean coal', and a very large underspend on renewables.

So what will a sensible energy development portfolio look like? Well 'clean coal' so-called, might have 15%, 20% of that portfolio, not 90% which is what it has at present. And renewables will have the remainder, because renewables in all its diversity, in my opinion, will provide the majority of energy, clean energy, by about 2040. So there's plenty of upside for future solar energy, the world record efficient solar cell is 43%, there's no reason it shouldn't go to 86%. We've got a huge growth rate, large reductions in cost in the offing, and we can make it by 2040 or 2050. And we've got a foothold in this industry, let's support it.

The worldwide electricity consumption is going up by 2% or 3% per year. The PV industry, the photovoltaic industry, is growing over the last 20 years at 23% per year, and a lot more than that in recent years, and in fact when you extrapolate that out into the future, all of the world's electricity will come from photovoltaics in 2050. Thank you.

Peter Mares: Thank you, Professor Andrew Blakers. And there we are, we can be confident that by 2050 all our electricity will come from photovoltaics, from solar energy.

From harnessing heat that comes from high above, from the sun, we now turn to tapping energy that lies far, far below. In the hat fractured rocks that lie beneath our feet. Well perhaps not exactly beneath our fee there in Melbourne, but perhaps under the desert plains of the Cooper Basin.

Dr Adrian Williams is a true believer in the potential of geothermal power to meet future energy needs. And this conviction comes after working across the energy industry as an engineer, from natural gas fields in Algeria to hydro projects in South East Asia and as the former Head of CSIRO's Energy Division.

For the past eight years, Adrian Williams has been working with Geodynamics Limited, which is hoping to demonstrate the proof of the hot rocks pudding in the Australian outback. Please make him welcome.

Adrian Williams: Well thank you very much, and it gives me enormous pleasure I think to talk to you tonight, particularly because I think we've got a good news story here; I'd like to share that with you.

We've just heard that I'll be talking about geothermal energy. A lot of us would be familiar with the geothermal energy that's associated with the volcanic regions in New Zealand. But we've got a different proposition in Australia. Geothermal energy that's associated with hot rocks. And that's what I'd like to be focusing on.

So what are we talking about? We're talking about thermal energy that's stored deep underground in hot granites. A lot of granites in the world are slightly radioactive with potassium, thorium, uranium in them and that decay generates heat. If the rocks were at the surface, that heat would just dissipate. But if they're buried with insulating sediments, over time those granites just get hotter and hotter and hotter.

So out in the Cooper Basin, they've got hot granites that start at a depth of 3,500 metres down, and they're insulated by the overlying sediments. Now we've drilled a couple of wells there so far, and Habanero 1 was a really important well, and it made some great discoveries. That showed that in fact the granites were naturally fractured, and that those fractures were full of water, and even better, that that water was under really high pressure, a pressure so that if we measured it at the surface, it would support a column of water 3.5 kilometres high, that's really high pressure. So that's exciting, because it means that if one well, we can produce that water to the surface, run that groundwater through a heat exchanger to take the thermal energy out of it and transfer it into another fluid that goes off to the turbines to generate power, the original groundwater can then be reinjected in a separate well, perhaps a kilometre away, or half a kilometre away back where it came from.

Now if you like that's a completely closed system. It's a proposition that does not require any external supply of water, we simply circulate the groundwater that's there, to draw the heat out of the hot granites. And then at the surface, we have a geothermal power station that doesn't mind where the hot fluid has come from. It's as simple as that. So we have a closed loop, we don't need water, and we have absolutely zero emissions.

Now all of the technologies to do this exist, so it's a simple proposition. Temperature is absolutely everything. It's like the grade of gold: the higher the grade of gold, the better the resource. In geothermal energy, temperature, absolutely dominates your economics. Out in the Cooper Basin we're looking at temperatures of around 235 degrees centigrade at the top of the granite, increasing to about 290 degrees at a depth of 5,000 metres. Those temperatures make the Cooper Basin rocks the hottest rocks of their type on earth. And that's really exciting.

You might be interested, but there's a lot of hot rock work going on in Germany right now. They're excited with 170 degrees. When things are hotter, clearly there's more energy, but it also means that the efficiency of converting thermal energy into electricity also increases. Really important.

The Cooper Basin would be recognised globally as one of the more significant potential geothermal resources in the world, and it's because of temperature.

But it's more than that. We need to get the heat out, we need to have good flow rates of moving that groundwater through the fractures in the rock to draw the heat out. Just to help visualise it, we're looking at producing out of one well, about 100 litres per second, that's about half a 44 gallon drum per second. At about 250 degrees Centigrade. And that, as I said before a really high pressure. The amount of energy that's contained in that flow of water, is equal to the annual output of about 10 wind turbines. The energy that we know about is enough to give us an annual power output equal to 15 Snowy schemes. We know that's there, there's no doubt about that. All we have to do is to demonstrate that we can get that energy to the surface efficiently.

The total Cooper Basin we estimate contains enough energy to support the generation of power equal to all of the current output of Australia's coal fired power stations, for something like 250 years. There's an enormous amount of energy up there in the Cooper Basin.

For new projects, we believe that for a price on carbon that's something over $20 to $30 per tonne; power from hot rocks will be very, very competitive. To us there is no doubt that we will be cheaper than all of the fossil fuel based power options. We believe our costs will be comparable to nuclear if that's what we want to do, we believe at the moment though we'll be cheaper than wind or solar.

But people say the Cooper Basin's a long way from anywhere, and it is. But you know, it doesn't matter. First of all there are a whole lot of companies working up here, this is not just one company with a small resource, there are a number of companies and very large resources. And at the end of the day, if you have a large resource and it's a very high quality, it makes sense to take the infrastructure to it. It happens all over the world; it's happened with the railway lines in the Pilbara for example. The right technology to take power from the Cooper Basin to the national grid, is direct current, because the energy losses with transmission are quite low. We are looking at energy losses, transmission losses of around 5% to Adelaide, around 7% to Brisbane and Sydney. That's not a big issue. But it's simply a question of cost. And the cost of those transmission lines will be in the range of $10-$12 a megawatt hour. And it's purely a question of economics.

So our plan is first generation of hot rock power by the end of this year. The first 50 megawatts by 2011; 500 megawatts, and that's enough to power about 330,000 homes, we expect to have that into the grid by 2016. And then we head up to 10,000 megawatts that we already know about. So if I can just finish by summarising Australia's opportunity with geothermal energy.

It is quite easy to develop a conservative scenario looking at how things might grow, and out to 2030 we can see geothermal energy meeting 7% to 10%. If you took an aggressive position, you could roughly double that, but that is a conservative position. I'd like to leave you on that good note. Thank you.

Peter Mares: Thank you, Dr Adrian Williams. So we can see that Professor Blakers was wrong; we won't be having entire solar energy, by 2050, we'll have 7% to 10% or maybe a bit more of that geothermal stuff from those hot rocks.

You're listening to Big Ideas on ABC Radio National, and a program coming to you from Federation Square in Melbourne: a conversation about energy and climate change and the role that renewable technologies can play in helping Australia reduce greenhouse gas emissions.

Our third speaker this evening thinks the answer to our energy needs may be blowing in the wind, or perhaps swishing about in the waves, or growing on trees.

Dominique La Fontaine is one of Australia's leading clean energy authorities with a high level of expertise in policy research and technology. She was the inaugural chief executive of the Clean Energy Council, a position she held until moving on recently to pursue a career as an independent strategist and consultant on climate change policy. Please welcome Dominique La Fontaine.

Dominique La Fontaine: Can I just say it's funny, every technology has the answer, but it's important to know that we do not have to feel that a world, or a country just with a whole lot of fossil fuels that there's no other way for us forward; there is plenty of technologies and plenty of approaches out there, and in fact most importantly, what we do need is diversity. And we've heard about the energy from the sun, geothermal, and I'm going to talk to you a little bit tonight about wind, bio-energy and ocean.

But first of all, why is so-called stationary energy important? Well basically because one half of Australia's emissions come from the stationary energy sector, the energy that we use to power our homes, to light our homes and our industry contributes one half, that's 50% of Australia's emissions. This can be compared to sectors like transport or agriculture, which are the next largest sectors. They're in the order of around 15% in terms of the contribution to Australia's emissions.

But in terms of how we can reduce emissions in the quickest way possible, it's my strong belief that we can focus on the stationary energy sector because we do have the technology available to us. In Australia, 80% of our electricity comes from coal, and about 10% from gas, and the remainder from hydro and a too small percentage from other technologies like wind energy and bio-energy, and we have the great opportunity, the potential of these cleaner technologies, but in the past we haven't had the policy frameworks that will drive the investment that's needed to make those projects happen. And while we have been heavily reliant on coal and it's been cheap, it's been a double-edged sword. Now that the world understands the reality and the urgency of climate change, Australia's economy, being so dependent on coal, is now greatly exposed. So it's absolutely essential that we change the ways that we make energy, and we find cleaner ways of doing so.

Professor Garnaut, you may have all heard about the Garnaut Review; one of the most interesting things that I think he has said is that it's absolutely essential Australia do what it can to reduce its own emissions, because we have everything to lose when it comes to the world not being able to address emissions reduction. Australia is a climate of extremes, and with the advent of climate change, and if we cannot get it under control, Australia's climate will be every more severely affected than what we're starting to see now already. So the time for us disputing over whether something costs too much, I believe are past us. It is about opportunity and innovation, and we need to be able to embrace that.

Before I go into the renewable energy technologies, I want to make a point about energy efficiency or energy conservation. If we use electricity in smarter ways, we're going to burn less fossil fuel, and we're going to reduce our power bills, so that's essential. Energy consumption of residential and commercial buildings is responsible for 23% of Australia's greenhouse gas emissions so it's a significant chunk. Commercial buildings could reduce their energy by 30% and still accommodate the growth in buildings by 2050. And energy efficiency means using very simple improvements and practices like insulation, light fittings, ventilation and turning off power. So that is definitely within our grasp, and recent studies have shown that energy efficiency is the most cost-effective way that we can reduce emissions.

But now to a clean energy option: windpower. I'm sure most of you have probably seen a wind turbine, if not a wind farm, in fact wind energy has been, if you like, the harbinger of clean energy and has stimulated great debate, which has been fantastic, but it's got the issue on the table. Windpower at the moment is one of the most cost-effective renewable energy resources. Windpower is one of the oldest energy technologies known to man But over the last 20, 25 years, it's gone through amazing technological improvement, so that it's one of the most efficient as well as transferring the energy that's in the wind into electricity. The blades of the turbine are specially designed to capture the wind and drive an electric generator to produce power which is exported to an electricity grid, and then that's distributed to the homes and industry. So in that sense, although it's very sophisticated technology, it's actually quite simple.

Wind speeds of about 8 metres make excellent wind sites, and that would feel like a fresh breeze at ground level; that gives you some feel of what 8 metres per second is. And the best wind sites are consistent, so you have a very consistent breeze, and they are predictable. And Australia is very fortunate to be a country that abounds with very good wind sites. Like our solar resources, like our geothermal resources, we are the envy of the world.

Installed capacity in Australia, there's about 817 megawatts, which is only really very small to what it could be, and it currently equates to savings of frequency million tonnes of carbondioxide per year, which is equivalent to taking 750,000 cars off our roads, or planting 4.86 million trees. So that gives you some idea of what the current capacity is.

Absolutely no water is needed. The other thing that is often said about coal-fired power generation is that it's quite a large user of water. So one of the good things about wind energy is that it doesn't need water to make the electricity. Studies show that the existing grid, transmission grid, can take up to 8,000 megawatts. Now we're currently at 817 nationally, we've had a renewable energy target in Victoria which will see us come up to a thousand megawatts just in Victoria. We still have a long way to go because there's a lot of projects on the books, there's a lot of wind sites, very strong consistent winds. In northwest Tasmania there are capacity factors there being reported in the order of 60% at some times of the year because the wind speeds are so consistent.

Wind power is a major growth industry globally. It's the fastest growing clean energy industry around the world. Over 15,000 megawatts of new capacity was installed in 2006, and this equates to the value of around $30 billion.

The industry achieved a rapid growth rate of 32% in 2006 and 41% in 2005. And that growth is purely and simply driven by the certainty that's provided by the right policy frameworks that governments put in place. Renewable energy targets, carbon pricing, feed-in tariffs, there's a very road range of policies that can be put in place to provide the investment certainty that's needed, and business response.

I might also make a comment about windpower and rural development. I know that there's been a lot in the press, and it's started with the good old orange-bellied parrot which was interesting, it started to really stimulate debate, which was a good thing. There is absolutely no reason why and every reason why we can incorporate wind farms and other clean energy infrastructure into our rural areas. As we decentralise energy generation, at the moment electricity is made in some fairly discrete places and as we move to a cleaner energy future, we're going to be building more clean energy infrastructure around many more places, so we have to be able to address this issue of where do we put them? Where do we build them? They've obviously got to be in the places where the solar resource is, where the geothermal resource is, where the wind resource is. And to do that, we have to be able to collaborate with the community who live in these areas. And with my time at the Australian Wind Energy Association, I was intimately involved in driving some very innovative planning practices that did enable companies to engage the community to enable the community to have ownership of the development. And that's very important that that continues.

Just to move to bio-energy. Bio-energy for those who don't know, is the use of animal and plant products to make energy. The Australian sugar industry has used bio-energy for over 100 years, so there you have another technology that's been around for a long time. The power can be stored and controlled and one megawatt hour of bio-energy derived electricity avoids approximately 1 tonne of CO2. But power can generated in many cases all year round, 24 hours, and in Australia, bio-energy already supplies enough electricity which is equivalent to the needs of 400,000 households. Bio-energy resources again, are located in all the regions of Australia where the regions are engaged in agriculture, forestry, and food production. So there is significant potential for growth in this industry and it's actually another very clever way of using the waste for many processes.

Another clean energy option which is more in the developmental phase, but it's a very exciting technology for a country like Australia which has an amazing coastline, is ocean power. And this uses the ocean's tides, the currents and waves to make electricity. It uses either the flow of water or the changing height of water go turn a hydro turbine. There are a couple of developments going on at the moment which are very exciting. The Australian company called Oceanlinks has installed a 5400 kilowatt wave power unit at Port Kembla, New South Wales, and it plans to install 10 units in Portland with peak capacity of 15 megawatts.

The Victorian unit has the potential to supply the needs of about 15,000 homes in the local area. And the Carnegie Corporation is trialling undersea, mounted wave technology, and is planning to install a small array of its units off Fremantle by the end of 2008.

So you've heard a wider range of technologies and I've only touched on those there. What we need to move this forward, as I said, is the right policy frameworks; we need the markets in place, we need to look at the rules that govern the electricity grid which after all was developed around large-scale fossil fuel generation. We need to make sure that the rules and regulations which are quite substantial, reflect the different characteristics of renewable energy. Very importantly, we need to make sure that we have the skills and capacity in Australia as the skill shortage is something which affects the growth of this industry, like any other.

Most importantly, we can be very confident that renewable energy is reliable and predictable, and we can build our economy on these clean energy options. Thank you.

Peter Mares: Thank you very much, Dominique La Fontaine, Immediate Past CEO of the Clean Energy Council.

So we've been presented with a range of renewable energy options: solar, geothermal, wind, waves, biomass, all hold promise and all have the advantage of producing few, if any, greenhouse gas emissions. But every technology choice presented here tonight also throws up problems and challenges. The difficulty facing government is knowing which technology to back. Should we try to pick a winner? Should we throw money at everything, or should we just set a price for carbon and let the market decide?

To help us to get a clearer perspective of what we've hears to far tonight, I'm pleased to welcome our chief commentator to the stage. Dr Graeme Pearman has been working on climate change for more than two decades, for longer than most of us knew it was even an issue. He provides scientific advice to Al Gore and has published more academic papers and won more awards than most of us have had hot dinners.

Dr Pearman is former Chief of Atmospheric Research at CSIRO and now runs his own consultancy. He's both scientist, eminent scientist and committed environmentalist. Graeme Pearman.

Graeme Pearman: This is a positive story, we have options available but we do need them. We need them because this issue of getting our emissions down is actually very urgent. This is particularly the case I think that because even the science that was summarised in reviews of the IPCC last year in February, we find that there have been changes since that were not anticipated. There are many of these. I'll give you one example.

We now know that the area of desert oceans - that is the oceans in which there is very little primary production, averaged over all of the North Atlantic, South Atlantic, North Pacific and South Pacific are increasing by between 1% and 4% per year, because of the stabilisation of the ocean circulation due to the warmer surface. We understood that this would happen but we had no idea it was already happening until about two months ago.

The urgency is that we will have to set higher targets and the Garnaut Review, Ross Garnaut has already indicated in a preview I think, that he understands now that there are these demands in urgency and for Australia that's compounded by the fact that there are issues around equity. The distribution of emissions globally are inequitable, but so are the impacts of climate change we anticipate, and so are the capacities to deal with this, and at the end of the day somehow or other governments like the Australian government are going to have to deal not only with the scientific urgency, but also with the equity issues.

The portfolio, or range of different options Dominique mentioned, the diversity that's necessary, is definitely worth mentioning and I think this was behind the design of these two sets of lectures. We have a range of different opportunities out there; we need to explore them all. Why is this? Well some of you listening to the presentations of the three proponents, I might call them with due respect, would notice that they are examining not only the technical feasibility of these things, in some cases well and truly proven, but also the issue around costs. The reality is that for many of these things, we don't know what the costs will be and we don't know how the costs will unfold, if for no other reason we don't know what the price of carbon will be when we have a trading system. But we also actually have issues around the rate at which we can scale up to produce reductions that we need.

To give you a feel for this, for example, we currently as was pointed out in one of the presentations, require over 2% growth in energy to meet demand in Australia, per annum. So that to stabilise our emissions alone, somehow we have to transfer 2% of our energy demand from the conventional carbondioxide emitting technologies to these alternatives. That in itself is not an easy task, but I think that the evidence, or the suggestions in Garnaut's report but coming now out of the science, is that we will need to have targets that are actually harder than what the Labor Party's policy is, which suggests we may be looking at more like 20% reduction in emissions by 2020. To do that, I don't know whether it's possible to be quite frank, but that requires annual transfer from those older technologies to new technologies - whether it be these or clean coal or the other technologies we'll hear about next week - requires more like a 5% per annum transfer. This is an enormous challenge.

So we need diversity to be able to actually meet the range of reductions we need but we also need the diversity because some things can be done quickly and some things will take some time. The availability of technologies to reach both the emission reductions but the demand for growth in energy requires this kind of portfolio approach, and this is a challenge. It's a challenge because we do have well-meaning advocates of each of these technologies and that's fine, that's really good. But at the end of the day, there will have to be intervention in some way through government to drive this and governments have to make wise decisions about how to maintain and balance the options, because some of the options will turn out to be not the right options and the fundamental requirement of a portfolio is to maintain diversity sufficiently enough that we don't find, as we go down the track, we've taken the wrong route and then we have real problems on our hands. Thank you.

Peter Mares: Dr Graeme Pearman, former Chief of Atmospheric Research at the CSIRO speaking at the first of two public forums discussing Energy and Climate Change, Science and Technology for Australia's Future.

This is Big Ideas on ABC Radio National, and our focus this week is on renewable energy. Along with Graeme Pearman our speakers are solar energy specialist, Professor Andrew Blakers, former CEO of the Clean Energy Council, Dominique La Fontaine, and geothermal power entrepreneur, Dr Adrian Williams.

And it was Adrian Williams who took the first question from the floor. He was asked about the big challenge for the geothermal power, not the technology itself, but the cost of building transmission lines to get electricity from hot rock sites in Central Australia to users in our coastal cities.

Adrian Williams: Well to me there is absolutely no doubt that those power lines will be installed. We've done enough work to map out the scenario for doing that. Clearly there's been a challenge in deciding what size power line to build on day one. You might want economically to build a power line with a capacity of, say, 250 or 500 megawatts, but you won't actually have the generating capacity to fill that as soon as it's built, yet you need it there to accommodate your initial generating capacity. So there's a little ramp-up challenge. We believe that we're across that. But just if I could give you some other examples of where Australia has grappled with these sorts of infrastructure challenges.

I mentioned the railway lines in the Pilbara to get iron ore to the coast. We've already got oil and gas pipelines from the Cooper Basin to Adelaide, Brisbane and Sydney, they've got a gas pipeline from the North West Shelf all the way to Bunbury, south of Dampier. So I'm quite relaxed in believing I think that if the economics are right, then Australia has got the capacity to undertake these major infrastructure projects.

Peter Mares: Another question just here.

Questioner: Geothermal energy is nothing but the removal of heat of the earth's interior. Does it have an effect on the earth's interior or the atmosphere and how long will it last?

Peter Mares: So, two questions, how long will geo-thermal energy last, and taking that heat out of the earth, what effect does it have? Does it have any impact?

Adrian Williams: Let's just talk about taking heat out. It's quite different I guess to taking out oil or gas where you remove physical matter from porous structures within the earth, so taking out heat is quite different to that. Clearly if you cool rocks they will contract a little bit, but the amount that they contract is absolutely tiny compared with the volume change you would get, or the contraction you would get from producing say, oil or gas or water in fact.

Peter Mares: And you mentioned the fact that the heat comes from radioactive sources in the hot rocks, so is there a radiation risk associated with geothermal energy?

Adrian Williams: No, there isn't. There is a small amount of radon contained within the groundwater that's circulated, but we're relaxed about that on two counts. First of all, it's a completely closed system, so that groundwater never ever sees the light of day. But you say, 'Well what if there's an accident? What if there's a pipe burst, or something goes wrong?' Well radon is one of those radioactive elements that has a very, very short half-life, it might be half a day, or something like that and it's gone. So there will be a small amount of radon, but in practical terms it's a non-issue.

Peter Mares: Another question just here.

Questioner: Andrew, I wanted to ask on photovoltaics what you felt the most cost-effective way of rolling out the photovoltaics would be. Whether it's solar thermal, or photovoltaics on a whole range of buildings, or photovoltaics that are concentrated in large areas in the desert?

Andrew Blakers: It will be different for different times and different countries. By far the largest rollout of photovoltaics at the moment is on house roofs because there's attractive support from government in certain European countries and Japan and some United States. In the long term of course it's certainly going to be cheaper to do it on that scale in the desert whether it's flat pipe photovoltaics or concentrating photovoltaics or concentrating solar thermal power. Solar hot water on your roof is a no-brainer if you haven't got one and you've got sunshine on your roof, then you're nuts, you should go out and get it straight away. There's a very important plus point coming up for the residential sector. Solar hot water and solar photovoltaics on your roof does not compete against wholesale power, it competes against a retail daytime class of electricity, and that's going to be after about 20 cents per kilowatt hour within a couple of years, and the cost of photovoltaics will be below 20 cents per kilowatt hour in a few years, and at that point, the current very steep growth rate of photovoltaics is going to get even steeper.

Peter Mares: Can I just follow up very briefly, because there's a lot of talk about shortages of silicon to make the cells, and that will drive the cost up. I mean that's one of the criticisms.

Andrew Blakers: There's no shortage of silicon, it's the second most abundant element in the earth's crust. The shortage is in the hyper-purified 99s pure silicon and the problem there is that it's a skill-intensive industry and it's taking a long time to rapidly, rapidly grow that industry to try and catch up with the rapidly rapidly growing photovoltaic industry. Some people say it will catch up within the next few years, but on the other hand the PV industry's growing so fast that perhaps it won't catch up for quite a few years which is pinning prices at a somewhat higher level than is desirable. But then if the price is too high then the demand will go down and the silicon supply will catch up.

Peter Mares: We have another question here I think.

Questioner: All the options that have been presented here tonight of course lead to the generation of electricity. Now once you've got electricity, it's very easy to make hydrogen. I wonder if any of the panellists would like to comment on the possible future role of hydrogen for the storage of this energy, particularly for transport.

Adrian Williams: There are a lot of people who love the idea of hydrogen, but I don't happen to be one of them. I wonder why, if we're looking at transport, which is where there's perhaps more opportunity than elsewhere, why would you generate electricity to produce hydrogen to produce electricity? That doesn't seem to be smart to me. If we want to move away from fossil fuels to drive motor cars, let's make them electric.

Andrew Blakers: I think Adrian is correct. The most recent automotive conferences that I've been to have stressed quite strongly the possibility of cars going to electric. The limitation there is batteries and how good the batteries are and the cost of batteries and whether their environmentally friendly themselves, as the debate goes on with cars like the Prius. But I really don't think that this is necessarily the way to go.

Peter Mares: OK, gentleman there with the microphone and then I think this guy here was next.

Questioner: To reduce our greenhouse gases in Australia is commendable. And I think we'd all agree with that. But I'm led to believe that we only contribute less than 1% of the total greenhouse gases in the world, so our efforts would seem to be futile.

Peter Mares: Andrew Blakers:

Andrew Blakers: I would like to point out that I pay about one five-millionth of the amount of tax, so it doesn't make any difference whether I pay tax any more, are you all going to give me a tax holiday?

Peter Mares: I thought Andrew you were going to talk about China's use of solar power, because China's adopting solar power in a big way. But, Dominique.

Dominique La Fontaine: I touched in my presentation and so did Graeme on Professor Garnaut's view, and I would encourage you to have a look at that document because I think it very succinctly argues why even though Australia is a relatively small emitter, from the country perspective, compared to the larger entities like China and India and the US, politically Australia does punch way above its weight on the international stage. I was in Bali at the recent climate change discussions and I can tell you first hand that the so-called symbolic ratification of Kyoto by Prime Minister Rudd was much more than a symbol, it really drove those negotiations to see that Australia was finally back in the game. But Australia can't be influential if it's not prepared to do what we can physically do here. And I think the best thing that Australia can do to influence global action is to reduce the emissions here as much as we possibly can. And we have absolutely no reason not to do it, because we are so blessed with the resources and the know-how and the skills to do so.

Graeme Pearman: There are actually many answers to this and one of them is the equity issue that's been mentioned. There is a moral aspect to that as well, but there are other aspects. For example, had we have actually decided to do really kind things that Andrew talked about with solar energy 25 years ago when CSIRO for example was a strong leader in this, we maybe would have had the market share that China actually has in this area at the moment. This very rapid growth is something that we are not actually involved in at the moment, we are to a large extent cut out of it. In fact Andrew's optimistic about us getting into this and I think we should try to do that. But it is late.

Andrew Blakers: Just a quick comment, there's a couple of very important things that government has to do, and that is, it's a government's role to fund research and development and to make sure that the education required for skill development happens. We have a very, very narrow skill base and have a very, very narrow R&D base because of the last decade. That needs repair.

Peter Mares: Adrian.

Adrian Williams: It's interesting that various writers talking about the sustainability of society have identified the need to be good at making decisions. A society has got to be good at making tough decisions, and hard decisions. If a society can't do it, or if a company can't do it, they go under.

Peter Mares: OK, my apologies that we can't take more questions, and before I close a reminder that we'll be back here next Monday for the second conversation about energy and climate change. Dr Louis Wibberley from the CSIRO will talk about brown coal and gas; Peter Cook will talk about sequestration, that's sticking those greenhouse gases underground; and Ziggy Switkowski will talk about nuclear energy.

So I hope you can join us then. I'd like to thank the City of Melbourne for hosting tonight's event, ANZAS, the Australia and New Zealand Association for the Advancement of Science, and ATSE, the Australian Academy of Technological Sciences and Engineering, for their leadership in bringing this idea about and helping make the discussions happen. Please thank our panel and a special thanks to you, our audience, for coming along to take part in this very important discussion, and I do hope to see you next week.

And I'll be back on Big Ideas next week to bring you that second forum on Energy and Climate Change, Science and Technology for Australia's future, discussing whether 'dirty coal' can be made clean, and whether Australia should opt for nuclear power.

In this program you heard solar power specialist, Professor Andrew Blakers, Director of the Centre for Sustainable Energy Systems at the Australian National University. Dr Adrian Williams, former CEO and ongoing advisor to Geodynamics Limited, the company attempting to harness power from hot rocks in the Cooper Basin. Climate change strategist, Dominique La Fontaine, who's immediate past CEO of the Clean Energy Council. And scientist and consultant, Dr Graeme Pearman, former Chief of Atmospheric Research at the CSIRO.

I'm Peter Mares and I hope you can join me at the same time next week for Big Ideas, and more on energy and climate change on ABC Radio National.

Guests

Professor Andrew Blakers
Director, Centre for Sustainable Energy Systems,Australian National University

Dr Adrian Williams
adviser to Geodynamics Ltd

Dominique La Fontaine
climate change strategist

Dr Graeme Pearman
scientist and consultant

Peter Mares
Moderator

Further Information

Melbourne Conversations (City of Melbourne)

Australian Academy of Technological Sciences and Engineering

Australian and New Zealand Association for the Advancement of Science

Future leaders