Australia's renewable energy future
Solar thermal concentrators: Capturing the sun for large scale power generation and energy export
Tuesday, 7 April 2008
Associate Professor Keith Lovegrove
Solar Thermal Group leader
Department of Engineering
Australian National University
Keith Lovegrove is the leader of the Solar Thermal Group in the Department of Engineering at the Australian National University. He also teaches undergraduate and postgraduate courses in Energy Systems and Systems Engineering within the Department of Engineering. He has had a long involvement with The Australian and New Zealand Solar Energy Society, a section of the International Solar Energy Society. Dr Lovegrove has served in the past as Chair, Vice Chair and as Treasurer. During his time as Chair, he initiated the annual ‘Sustainable House Day’, held across both countries each September. He was also Chair of the organization’s Solar 2006 conference organising committee. He has authored or co-authored over 100 research papers and contributed to media interviews and reports on the renewable energy field.
Chair (Kurt Lambeck): Good evening. I'm Kurt Lambeck, President of the Academy of Science. I welcome you here to this lecture, part of the public lecture series, that examines the range of renewable energy technologies, including photovaltaics, wave energy and geothermal energy.
This lecture series is particularly useful at this time because we are going into the lead‑up to Kyoto 2 or Copenhagen 1. I was at the Copenhagen meeting a few weeks back, and one of the things that impressed me was the fact that at least the European industry community had accepted the reality of climate change, and they had accepted the reality of industry having to do something about CO2 emissions. At the same time they were seeing considerable opportunities in this.
While the climate message at Copenhagen 1 ‑ we will call it now ‑ the science part of it was rather gloomy, there was a certain amount of optimism coming from the industry community. And for us here at the Academy these lectures are quite important. They have been providing us with insights that we might not otherwise have had to help us prepare our science cases for government, for policy makers to make their policies on. So this evening's lecture I think is going to be a very useful part of that series.
Tonight's presenter is Keith Lovegrove, who will take on the question of solar thermal concentrators: capturing the sun for large scale power generation and energy export.
This is a project that in one form or another has been going on at the ANU since the time I came to the ANU in the mid‑70s, so I will be very interested to hear what has happening in the meantime.
Keith has been involved in the solar energy field for many years. He has co‑authored over a hundred research papers and he has contributed to the public debate on the issues and the energy renewable field in general.
So I think he is going to be very well qualified to address us this evening on the Australia's renewable energy, the prospects for solar concentration potential. So, Keith, over to you.
Keith Lovegrove: Thank you, Kurt, good evening everybody and thank you for coming.
Well, as Kurt said, I'm certainly not a climate scientist either, and every time I hear a bit of climate news it is actually really depressing. To be honest, I think we can all get a bit of an overload of the bad news, which doesn't take away from the fact that it is very bad indeed.
But on the upside, some of the technology solutions that we have available to us are actually a source of great optimism. In many ways it probably helps to concentrate on the optimistic side, and let's all just get on with it and strike down the nay sayers who try to tell us it's too hard, we have to go slower, it is just not going to happen. Well, it actually is. Interestingly enough, it already is happening in terms of the change, I think.
I am here tonight to talk about concentrating solar thermal power. Probably half of the talk is going to touch on what we do at ANU and some of our history. I am more interested in giving you an overview of the whole field, what is happening around the world and what its potential might be for a long‑term solution.
So what is concentrating solar power? It is all about mirrors and, hopefully, not too much smoke. There is basically four kinds of well‑adopted approaches to it now, which are about the geometry of the mirrors. What you see there, it is a parabolic trough. Mirrors track the sun from side to side during the day and focus all the radiation up to the linear receiver you can see at the focus.
Approach number two is to say, let's have one big receiver. Let's gather up all the energy there. Let's make it stationary and surround it with a field of heliostats, which are almost but not quite flat mirrors that all work independently to continuously bounce the sun up to that fixed point.
Approach number three, which is closest to our hearts at ANU, is the dish approach which is to make a parabolic bowl - a paraboloid if you want to be mathematically correct - and have it track the sun in two axis so it always points directly at the sun. Focuses all the radiation up to a point.
Finally, an approach which is, if you like, the linear hybrid of the central receiver. It is kind of like a trough version of this one. This is the one you might have heard quite a bit of media coverage of a company called Ausra, that used to be Solar Heat and Power: it originated in Australia. It is the Linear Fresnel approach.
So four approaches. There can be other variations on the theme.
In case you haven't noticed, I think we are in the middle of an energy revolution. We are in the middle of it, or at least the very beginnings of it. It is not that we are saying that we might need one, it is actually already happening.
Why? Well, you know why. We all know about the greenhouse issue. Let's not forget that nothing's changed, that per capita Australia is, depending on who's statistics you believe, either worst or second worst per capita emitter in the world. Nothing to be proud of, even though we are a small population.
Don't forget that we have this issue of oil running out.
There's considerable debate about when peak oil is or was. Essentially no debate that it is around about now. It's an empirical fact that the amount of discovered oil just drops year by year and it has almost vanished. It is not for want of people drilling holes and looking. So the idea that we have actually got to the point where demand exceeds supply in oil is, I think, beyond argument. In many ways, we can all be complacent.
If you have see Al Gore's movie about climate change he has got this analogy of the frog in boiling water. For animal rights reasons he had to show an animated graphic and not a real frog in water, but it is a very good point. It is an issue that creeps up on you and you just say, 'Oh, we can wait. We can wait.'
Well, the interesting thing about the oil issue is that it won't wait for us. Demand will exceed supply. The price will go through the roof and suddenly we will look for other alternatives. Who knows, that might actually help us solve the climate problem.
When talking to my engineering students I like to point out that I was born around there (1960) and most of them seem to have been born around there (1990), which I find very depressing. But I point out to them that half of the world's oil was used only in one lifetime. Basically, in the space of their careers we won't use oil any more.
Actually, if you are a fresh new engineer coming out into the marketplace that's terrific, that's all about opportunity. It means we need engineers who know about energy and they won't be short of jobs.
Where does energy go to and come from in Australia? I just want to show you this. Don't worry about the detail, I just want to look at the big export arrow: we actually export in energy terms about as much as we use ourselves. Notice that a very big part of our exports is uranium. Although, you don't hear so much about that as you hear about coal exports ‑ I will come to why in a minute.
I could spend a whole lecture talking about all the different possibilities of where future energy will come from.
In this series you will have heard about some of the renewable alternatives, but probably not much discussion of the non‑renewable ones. I have just noticed that on my bullet point list I have left out geothermal ‑ it is sitting in the 'other', but I think geothermal is not to be under‑estimated. I will leave those comments for you subliminally, but I am here to talk about solar and specifically concentrating solar thermal.
There's the elephant in the room, I think. What keeps us alive? What pays for the Academy of Science and my job and everybody else's job and everything else? It is coal exports. It is our biggest source of export income. It is what our economy runs on. So in all of this debate it is not about how does Australia reduce its emissions at all. It is probably easier for us to do that than many, many other people.
What do we do when Japan doesn't want Australian coal any more because they have made a switch to another technology? Then we are going to be in big trouble. And we don't seem to have that debate.
So I'm going to talk about a technology tonight which I think actually solves both problems. We can certainly use it to make a big contribution to large scale emission reductions, but it is one of the very few things where you can say here is a straw to clutch out, how do we keep our export income going?
Back to the concentrators. Let's have a look at what's happening around the world.
I have been plugging away at this since 1987, which seems like a fairly long time, but others have been doing it for much longer. Not a lot has happened in quite some decades. In fact five years ago ‑ given this slide is a 2007 slide it is seven years ago ‑ you could just about write off concentrating solar thermal. Nothing much was happening. Nothing was being installed. A little dedicated research community was meeting year after year and talking about this proposal and that proposal, but nothing was getting built. But all of a sudden it has happened and we even get some newspaper coverage.
Why has it suddenly happened? The big success story in renewables globally I think is the large‑scale wind industry. It is a huge industry. It really grew. I guess it had its infancy in support in the US where a lot of early stuff happened, but really in recent history it's about Europe, about western Europe. Countries like Denmark and Germany and lately Spain, who haven't driven wind power. The European countries, as Kurt said, seem to have realised that climate change is an issue sooner than, say, America or Australia.
Well, if you are in those countries which renewable do you go for? It's obvious. You go for wind. You don't build solar power plants in Germany. So that's what they've done, and it is a huge industry and it's growing.
But it is growing so fast that I think there are serious limitations now about land‑based wind sites in Europe. The appetite for renewables is growing. What do you do? All of Europe's grid is connected. It's time to build solar plants in Spain.
These concentrating solar thermal plants are not small: they are not household scale, they are utility scale. So to take off as an industry you need demand at the utility scale and you need the countries who are driving the policy shift to have access to solar resource. That's what has happened. We have had a sudden resurgence in interest.
To go back a bit, a little bit of history ‑ this was on my first slide. A 10 megawatt tower system in California now mothballed. With these megawatt numbers, by the way, just to put it in context, Canberra's average or peak usage is 300 megawatts. So one would need 30 of those power stations to run Canberra at any given time.
This is the real success story, and it is the one upon which this industry can now take as its foundation and grow fast. These are trough plants: they are 20 years old. There is a total of 350‑odd megawatts of installed capacity there. They have been running for 20 years. All of that time it hasn't been economic because the policy measures weren't in place to build new ones. Given they had them and a range of different operating companies owned them, it was profitable to keep running them and they did.
If you have run a power station for 20 years that means that the technology is so proven it is almost worn out. No‑one can say it is untried technology. It is as proven as you can get.
Here is another point why this field has the potential to ramp up very fast indeed. The power house of essentially all of the establishments in existence, and being constructed at the moment, is steam turbines. Ninety percent of the world's electricity comes from a steam turbine. It is either coal driven or nuclear driven or maybe gas driven, or something like that. But it is a steam turbine. Your typical unit in a coal‑fired power station in Australia is 600 megawatts. Anything smaller than that is almost a special order. I am exaggerating a bit. But off‑the‑shelf are 600 megawatt units.
So the utility industry at a large scale is very comfortable with steam turbines. If you can build a solar plant with a 10 megawatt turbine you just make more mirrors and you have got a solar plant with a 600 megawatt turbine, and then you can start putting in full‑sized equivalents of coal‑fired power stations almost immediately.
So what happenned? This was the first one commissioned. This is an amazing bit of performance. It is basically a clone of the old prop plants but not the start date and the commissioning date. They built a 63 megawatt plant in just 15 months. It was the first one built for 20 years, by a company that hadn't done it before. So that wasn't bad going for your first try.
As I said before, the basic unit is a steam turbine. A 64 megawatt steam turbine is quite a small steam turbine by industry standards. The effort you have to put in and the time it takes you to make a 64 megawatt power block is almost identical to what you have to do to make a 600 megawatt power block. It's just smaller.
So if you wanted to make a 600 megawatt power station it shouldn't take you any more than 15 months. You just have more people making more mirrors in parallel.
Here's an aerial view of it and where it is. I don't know that being close to the gambling capital of the world was an analogy or anything. But let's hope not.
That was in the US. Simultaneously in Spain we have this start of activity. This plant, PS10, a 10 megawatt central receiver system got quite a bit of news coverage here when it opened in 2007. This is built by a company called Abengoa. I am not that familiar with the European scene, but they are a very major engineer procurer/contractor for the power industry. So they play in a large range of conventional power industry activities on a very large scale, and for them an activity like this is a small experiment to see if they like it.
To give you an idea, 600 heliostats 120 square metres each.
Just in case they weren't sure they immediately started building a 20 megawatt one right next to it. In fact, they consider this area here as their experimental platform. They have a total of 300 megawatts planned and under construction, including trough plants. This is a company that says this seems to be the way of the future, why don't we build one of everything at full scale to see if we like it.
When I say it's happening and it's optimistic and people are doing it anyway, well, this is the sort of thing when very large companies just decide to do it, and they try to pre‑empt the policy impact. Then you know it's probably going to happen.
This is an old slide. I borrowed them all from a guy called Michael Guyer (?) who was the secretary of this international energy agency program back in 2007. So this is a 2007 slide of a dirty paddock. For those of us in the community we actually grow a bit cynical about people showing photos of sites and announcing projects because for so long they have never come to fruition.
Well, that's it at the end of 2008. So they got in and they built it. So it is another trough plant, 50 megawatts electrical. But there's a very important point here: these two things are tanks that hold molten salt. These trough plants can heat their fluids up to 400 degrees Celsius. They have a tank of molten salt of 200 something degrees and they heat that to 400 and move it over to the other tank, and that is the stored energy. It is not rocket science. It is just a big tank of hot stuff. It is just an over‑sized hot water tank. That allows this plant to run for 7.5 hours at essentially nominal power output with no sun.
You can see that the tanks aren't really a big deal. If they wanted to build two or three more tanks and get more hours of storage they could. So this is the first commercial plant, I think, that really addresses the energy storage problem and actually implements it.
In the past we haven't had a lot of solar ‑ you know, renewables can't do baseload. How do you store the energy? It's all too hard. Those of us who know realise it is not really an issue. But this particular plant probably puts it to rest once and for all because they have built it. It is commercial. It is working and it has just started. Once again, I think it was about ‑ I don't know the exact start date ‑ but it is probably an 18‑month construction period on this one.
Back closer to home, a company called Solar Heat and Power grew out of the University of Sydney's research. You have probably heard mention of that from time to time. There is a demonstration at the Liddell Power Station that has been coming along fairly slowly, and I guess it's pretty much working now. I am taking some students up to see it in a week or two. But really what happened is that this company went off chasing venture capital in California and became Austra.
It is doing much more over there, to the extent where I think they have lost interest somewhat in a little demonstration in Australia.
This was launched late last year. It's a 5 megawatt system. It's small. It's their first venture into it. It appears to be working, and so we can expect to see big things from that company, I think.
Dishes are our favourite at ANU, and I will tell you a little bit about why we think they should be in a minute. There is actually not a lot of dish work going on in the world. What there is is based on relatively small dishes. These are about 50 square metres, I think, and run little Stirling engines. That's not the approach that we're using at the ANU. But, nonetheless, there are companies that have proposed to roll this out on a very large scale. We will see if they can do it or not.
Australia's quite active on the dish front through a company called Solar Systems, that has produced quite a lot of these models. They are 130 square metre dishes with photovoltaic receivers. Very high efficiency solar cells that require a lot of cooling to stop them actually over‑heating. So it's not a concentrating solar thermal application: it is a concentrating solar power application, if you like. It's actually a different way of using photovoltaics. They are doing quite well. They've also got plans to do a variation of this photovoltaic conversion with modular central receiver systems. And if you have heard about a big solar plant in Mildura being announced, that is this company taking their photovoltaic technology onto a tower system.
So there are a lot under construction. It is actually hard to keep track of. I am pretty sure that about half of these on the list really are in construction. It means there is probably a couple of hundred megawatts, even as we speak, being built. If you believe Wikapeadia, that's what it told me a while ago.
There is also a list of announced plants. It just goes on for pages and pages. To be honest, when you read about an announcement or a proposal take it with a pinch of salt. I think, roughly speaking, about 10 percent of announcements turn into real projects. But when you hear about 'ground breaking' and you see bulldozers then it's real.
Is it going to grow? I think we can learn from wind. Wind has been an amazing success story. I don't think people realise just how big it is. Let me show you this old graph. So 1984‑2002 exponential growth at about 20 percent per annum. That has made it the fastest growing industry in the world. More importantly, you see the cost of generated electricity decays exponentially in proportion to the growth. In fact, you can find a constant and there is a learning rate, there is a number that economists use to relate the two things.
That's typical of any technology, really, but particularly this large‑scale infrastructure-type technology as it develops and gets widely used.
A bit more on wind. They just keep growing. They are still running at 20 percent per annum. So the previous graph is a subset of the new one.
Notice that we have now hit over one perecent. Despite its incredible growth, it still didn't figure in the global energy balance. So it is just on the map. But if you are going at 20 percent per annum and you are still growing like that and you have hit one percent you can go home and do the maths and realise it is only actually a decade or so, probably two decades and you are at 300 percent of something. So arguably it will actually level off somewhere and not provide 100 percent of our electricity. But it is on a growth trajectory to make a very big difference quite soon, and that's important.
It is worth, I don't know, something like a US$50 billion a year turnover. Probably in excess of that by now. It is a really global industry.
That is what concentrating solar power aspires to be. It can obviously be utility scale. I've just shown you that.
Reputable people have done studies and said, if we have a similar kind of growth ‑ and there is absolutely no reason why we shouldn't have that sort of growth ‑ then we will see a similar kind of cost reduction and we will get down to costs of generating energy that are very similar and on a par with wind. What that will mean is that if you have got a windy site put up a wind turbine: if you have a sunny site put up a solar power station. But nobody's built a wind power station with energy storage. The big competitive advantage for the solar thermal is this very simple way of storing energy.
The cost projections are conservative ‑ the red line up there is the historic growth of wind. The pink line is a projected growth for concentrating solar thermals. So the projections that these studies are based on are actually being modest in saying, well, let's be a bit less than wind.
How is it that the costs decline? Well, you invent better stuff because you have got more money. You scale it up and it becomes more cost effective and you just mass produce it and that becomes cheaper. So cost savings from three sources.
If you believe the Nuclear Review a while ago ‑ well, actually I thought it was a very good review, but lots of bits got quoted out of context ‑ you might think from a graph like this that nuclear is cheaper than everything else. Except, if you read it carefully you will find that actually the top end costs didn't make it to that graph, and that it could be a range like that.
Over here on the renewables side the concentrating solar power, as argued by commercialising companies, wants to be towards the bottom end of the green band. Wind is right at the bottom. The ones in the middle are a fairly unbiased view of ‑ where it says 'CCS' that means carbon capture and storage. So it means fossil fuels with carbon capture and sequestration. And what you end up seeing is that it is actually, in economic terms ‑ I think this is a pretty fair assessment ‑ it is anybody's game. That actually almost begs a market mechanism and says, well, if you have renewable energy targets, if you have serious emissions trading with serious caps on it, you can actually let the market decide. That's as long as you believe that carbon capture and storage by sequestration is genuine and is permanent. And you have to think about the nuclear issues as well if you are willing to accept that.
So, that's the world. How about ANU? There is an overview of us. I suppose you can almost see the Academy of Science in there somewhere. That is our old dish.
A little bit of history. Kurt mentioned it goes back a long way. I would like to acknowledge Stephen Caniff (?) who I have just noticed in the audience there. The solar work at ANU was founded by Steve and Peter Cardon (?) back in 1971 or 1972 I think, Steve. So Stephen Caniff.
I won't tell you about the White Cliffs system. It is 14 dishes, small dishes, and it was where the group at ANU really kicked off.
The big dish at ANU that a lot of people might have heard about was Stephen's project. It was his vision to say that, well, one could look at 14 small dishes and say yes, technically it works well. It is nice. But if we just go big it is going to be more cost effective per square metre. That was his vision. This one was built. Finished in 1994, and has worked extremely well. It is proving the point that a big dish works. It is, indeed, cheaper than 14 small ones. What I am going to tell you about tonight is where we have taken it since then.
A few details. It was put together with a space frame technology, which you will see is a similar construction to that in sports halls and shopping stadiums and things like that. Very high precision pieces. The accuracy in those pieces defines the accuracy of the structure.
Really great for a prototype. It has got what is called altitude-azimuth [a horizontal angle measured clockwise from a north base line] tracking, which means the whole thing turns around on wheels whilst the dish can go up and down like this.
Right at the top there is a boiler that makes super heated steam, not a Stirling engine. A dish and a boiler like this can make any temperature and pressure of steam that everyone's ever built a steam turbine for. As distinct from the trough systems: although they use standard steam turbines they are limited in the temperatures they can achieve. If you remember thermodynamics from high school or college, higher temperatures mean higher efficiency. So that's the limitation.
The vision here ‑ and this is the vision that came from Peter and Steve right from the beginning ‑ is to have arrays and very large scale systems. You bring all the steam together to a central turbine. You don't have a single dish engine system. I think that is the right call.
So let's look at a bit more detail and say, well, why should we do dishes? They are more efficient. In fact, if we take this overseas study that compared towers and dishes and work our way through the different things that contribute to a system efficiency, and then substitute what we know about a dish, we find it is more efficient.
What do we know about a dish? It concentrates to a smaller spot. And one of the things you don't want is heat losses from that small spot. Well, the smaller the spot, the less the heat losses. If the dish concentrates more, it will have less thermal losses, therefore, receiver thermal efficiency is higher. It is pretty common sense that will be the case, and it is measured to be the case.
This a very important one: optical efficiency. It is easiest to understand in relation to tower systems. If you think of a heliostat tracking the sun during the day and moving it up to a stationary receiver on a tower, there will be times in the day when the sun's low in the sky, the tower is over here, the mirror is doing this. The projected area of the mirror to the sun is a lot smaller than the actual total area of mirror. That's what we mean by 'optical efficiency'.
A dish, on the other hand, is 100 percent pointed at the sun. So its total area collects sunlight all the time. That's its competitive advantage. That's why we have a much higher optical efficiency.
So we end up with, arguably, built on the same scale almost twice the output of a trough system. Then you have to say, well, will it cost twice as much per square metre to make it? Without boring you with the details, you can go through all of the components that make up the cost of a collector and realise that a lot of them are fixed. Like a mirror, for example, a mirror is a mirror, up to a point. So a trough mirror should cost less than a dish mirror.
The one bit that will cost more is the frame to hold it up because it is more complex. But that is maybe less than half the total cost. So if you put all those things together and add them up you find that a dish might cost 50 percent more to build per square metre, but it produces 100 percent more output, so it appears to be a winner. So we keep going.
But, more importantly, arguably, the higher concentration of dishes means that if you want to you can produce much higher temperatures. In fact, you can go up to 2,000, 3,000 degrees Celsius with a good dish. It's not much use to you because you have trouble finding materials that can even use that. So you tend to use it at much lower temperatures. But at those higher temperatures you can drive any chemical reaction, thermochemical reaction that you can think of, and do a whole lot of really interesting things in the chemical space, which is really where I am going to get to at the very end of the talk, and talk about how we might export energy.
Why should they be big? It was Steve's vision to make it big. To be honest, we thought we'd better just check. We carefully analysed the dependence on radius of the various bits that make up the cost of a dish. What does that mean? Well, if you think about a mirror, a mirror costs a certain amount per square metre. It is like the area. It doesn't matter, therefore, whether you have small dishes or big dishes, the mirror is going to cost about the same. There is a lot of things like control systems where you need one for every dish, whether it's big or small. So they are fixed costs. But then there is the structure itself. That's where it kills you in a way, because the bigger you make it the cost of the structure is a cubic thing. There are wind forces to overcome and they are area dependent. Then you have to hold it up against a lever arm. That is a radius‑dependent thing. So you get a cubed cost to the structure.
When you put all that together and you look at the graph, well, it looks like this black line here. Depending on the assumptions you make, it could be in that range there. But whichever way you cut it, it seems to say a big dish is a good idea, but not infinitely big. Maybe a 11, 12, 13, 14 15 metre radius. But it is quite flat. So there is not a lot of incentive to go much bigger. But there is a pretty clear indication that going too small doesn't seem to work, at least on the assumptions we are making. So we are pretty sure big is good.
Just by the way, our approach to energy storage. This also goes back to Peter Cardon's pioneering work in the 1970s. But we are still working away on it. It is a different approach. It uses chemical reactions.
I am not going to talk about it too much, but make the point that it builds on an existing well‑established industry. Actually, virtually the largest chemical process industry in the world. By tapping into this industry it means you can launch straight into utility scale, because the building blocks at the end where you are recovering the energy already exists on a large scale. You can just jump straight in at that scale, as long as you can show one dish works.
The good news for us at ANU and for the world, hopefully, is that this technology, after many years, was licensed to a local Canberra start‑up company back in 2005. That has been the source of the activities that I am going to talk about now. Wizard Power got themselves an AusIndustry Grant under the previous government, which has allowed a number of things to go forward.
Take the idea of a big dish: it seems to work. Let's completely re‑engineer it as if we are going to build hundreds or thousands of them ‑ so engineered for mass production. What do we end up with? Something that looks like this. It has got a little bit bigger, not because it needed to get bigger but because the way we designed it it just fitted better. Focal length is 13.4 metres. It is still a very similar geometry to that one.
One of the mass production features is to go to identical mirror panels. We ended up making them square ‑ this dimension here. So every single mirror panel is mass produced, whereas this beast had hand‑made mirror panels that were all different.
Another key point is that the accuracy of the dish has come from forming it on a jig. We actually invested almost as much as the cost of a dish tomake the jig; putting all the accuracy in there so we didn't need such high precision components to put it together. So there's more tolerance in the components; cheaper components mass produced.
A little bit about design process. We teach an inter‑disciplinary systems engineering degree in the College of Engineering and Computer Science. We are very big on systems design and always make the point that before you begin you work out what the customer really needs, even if they don't know it themselves. This is what we summised a start‑up company like Wizard Power needs. The mission statement is to make a big dish. It is going to be around about the same size.
Obviously it needs to be as cheap as possible because we are after the cheapest energy. But we need to think about the risk and failure in the first system. It is not much good if it doesn't attract investors because it is too scary or something. Other things as well, but it is good to think about these at the beginning.
(Click on image for a larger version)
Design is an iterative process of creation and analysis. Probably don't need to tell you that.
For a complicated system, we break it up into subsystems that we can address individually. But a very important point of good systems engineering is to never forget the linkages. You don't break it up and send little groups off to make their bit and then hope that when they come back it all joins together.
On the contrary, you try to think about, well, if I do this to the mirrors what does it do to the receiver? What does it do to the structure? You constantly look at the interconnections, which makes design harder and slower. But it is your chance to really optimise it.
To give you an idea, we have now worked on the design of the mirror panels so that they actually make a structural contribution. And that means a cheaper structure. So by thinking of the two things together as a system you get a better whole than if you just look at them in isolation.
We have ended up coming back to the older altitude-azimuth dish, and it is going to look, from a distance, very similar to the old one. We had a look at some pretty ridiculous ideas and also some fairly standard ideas. That is the geometry of the little dishes at White Cliffs, for example. We looked at the cost implications of all of these; there were quite a few on our list, and a few silly ones. Quite a few that came in about the same. So in the end we said, well, if it ain't broke why fix it? So we have kept the older altitude-azimuth geometry from the previous dish because it is as good as anything we can find.
It started last February. Let me run you a little guided tour of our stressful year or so. We started with some site work.
Because we were told, if you don't want a six‑metre easement you had better build these humungous great posts here so that if we have to come along and dig up the sewer main your dish doesn't fall on our heads. That's why we had to put all these in.
This is little bits of project as you go. A great big slab on the ground not to hold up the dish.
This is the big slab getting poured to build the jig on it that I was talking about. We have invested almost as much in this slab and this jig as it would cost to replicate one dish. This is to prove the point. We have now packed up this jig and Wizard Power are going to take it away to their first site ‑ I will tell you about that in a second. It is actually in South Australia. So building up the jig.
A bit of surveying going on.
Jigs are a pretty agricultural bit of operation. Just a whole lot of frames out of steel.
Then scaffolding planks so we could walk on it.
But here is the key bit. All those little white spots there are optical targets. This photo is taken 30 metres up in a crane. The support points for the dish construction are those white spots. You get up in a crane and you take about 20 photos from all different angles around the dish and use a process called photogrametry and analyse exactly where these spots are in space.
Then you go down and you screw them up and down. And then you come back the next week and you do it again and then you do it again. At the end of it all our data was saying that we had these locations plus or minus 0.4 millimetres from the ideal parabaloid.
Then we twiddled our thumbs for a very long time waiting for this shipping container to arrive from China. The design we came up with to get the mass production and manufacturing to happen, and what Wizard Power commissioned, is a machine for this.
That is a piece of the dish getting made. The input is that.
It is a coil of sheet metal. This is at the back end of the shipping container.
It just goes into a machine and comes out. It comes out continuously at about a metre per second. That's what you make the dish from. Not only does it come out like that, but we curve it into the shape we want and then you just lop it off when it is the length you want and carry it over and put it on the jig. That's how you mass produce a dish in the field. You just take the shipping container. Build up the jig. Roll this out. Plop it on the jig. Make a dish. Take it off the jig over and over again all at the same site.
There are the bits going up on the jig. We made a square lattice like this.
There is actually an automatic riveter going around there. It took a day or so to do all the rivets.
In the meantime we had these beasts sitting in the paddock getting ready to take over the world. They were prepared in advance.
They go on the back as structural elements. Little pyramids all over it.
Then a bit of fairly manual stuff. We get up there and we stitch it all together as a complete frame with onsite welding.
Looking pretty finished now on its jig.
A beam to do the actuation.
Then we come to last Tuesday morning with our hearts in our mouths. Will it go spring? Will the cranes drop it? Will the cranes not be big enough? But no, it was a good day and it all happened. And there it be. So that was last Tuesday.
Just by the way, a crane like this, it is called a 100 ton crane. It can lift 100 tons straight up in the air, but not at an angle. It was right on the limit of what it could capably do. If it didn't quite make it we would have had to get in a 200 ton crane from Sydney at an extra $20,000 or so and wait several weeks. So we are very pleased that it did work.
And now the jig has gone. What you see here is us forming up a rail. We were recycling the slab needed to build the jig, but we were going to recycle it as the foundation for the dish. A rail goes in and then a base frame to accept the dish to do the altitude-azimuth tracking. It will be very similar to the old dish in many ways, but just a straight welded construction.
Mirror panels ready to go.
Okay, so that's us now. Back to the subject of how we shall get rid of those coal exports or, to put it a bit more diplomatically, what transition can we think of?
How are we going to make a living as a country? Well, gas gets a lot of publicity. The gas people have told you that by being half as dirty they must therefore be clean, which is pretty good marketing, I reckon. They are also doing quite a good job of exporting the stuff.
But as far as I have read - and maybe they will discover some more, and maybe they have - if you tried to run our entire economy and our exports on all known reserves of Australian gas, that's only 10‑years worth of running. There isn't really a future in gas for Australia. Cross that one off.
Here's an interesting one. You hear about coal exports keeping the economy up. Well, there they are again on another graph. On the previous graph uranium didn't even figure yet. In energy terms we export almost as much uranium energy as we export coal energy. Whatever you think about the uranium debate ‑ and there are a whole lot of other issues one could go into ‑ just think about that. The whole point of uranium is it has a very high energy density. If you build a nuclear power station you are putting all the investment in the power station and getting very cheap fuel.
If that's where the world is going, you don't want to be in the business of selling fuel. That won't help us at all. We would be down $23 billion a year if you swapped it in energy terms for the coal. So that's not going to save us either.
Or maybe we won't.
So why don't we re‑engineer ourselves as the manufacturing powerhouse of the world? Well, maybe we will, maybe we won't. I don't know. The good news is that it is sunny in Australia and doesn't seem to be about to get any less sunny. Arguably about the sunniest continent in the planet, per square metre .
If you look at the solar resource, these statistics have been around forever. There is an enormous amount of solar resource. This is total world resources of these things. That is annual solar energy hitting the planet. By the way, photosynthesis, the biomass of wind and hydro are all a natural processing of the solar energy. So there is going to be plenty of it.
What if we tried to meet all of our current fossil fuel needs using some mix of the technologies I've just shown you using reasonable land usage? How big is it? I have shown this many times before. It is that big, roughly, in case you can't see it. I have put it in a typical solar band. You know, do we build it out here? I suggest not. Our grid extends out to about here. Our loads are all down here. When solar systems are built in Mildura it is for a very good reason. It is a good optimum location. Anywhere in western New South Wales will do. And that's it. You don't build it all in one place. You scatter it around. It's completely compatible with grazing as a land use. Everybody's a winner.
How do you export it? You can do things like this. I put up this equation, just carbon, because coal is just carbon. You do a reaction like this and you end up with a gas mixture that you can turn into methanol, which is a liquid. And V8 supercars run on it, so how bad can it be? It is liquid hydrocarbon. You can export it. If you solar gasified coal, the end product would be about 30 percent solar. That would be a good transition. Maybe we can solar gasify a sustainable biomass.
We are dabbling together with Mike Djordjevic from the Research School of Biological Sciences in looking at algae as a vector. Algae is one of the high-production, more sustainable biomass sources one can look at, and very amenable to gasification in the solar thermal system. We are looking at a dish that can make any pressure and temperature of steam you want. There is a concept called 'super critical steam' ‑ I won't bore you with the details ‑ but it is super good. It is taking steam to a state where its chemical properties change and it becomes very good at breaking down hydrocarbons. So you literally dissolve algae and super critical steam. We are doing some very early stage experiments in the lab now. Haven't yet put it on a dish. It's so simple it clearly will go on a dish.
So solar gasified algae makes a mixture of hydrogen and carbon monoxide. We tap into an existing industry. This is the vision. We are trying to export energy on a large scale using as much as we can of existing infrastructure, meaning tankers for hydrocarbon liquids. We can certainly look at the gasification of algae. In the longer term maybe we can directly split water and ‑ Mike might not like this too much ‑ maybe the dishes can do it on their own, or maybe there's a mixture.
One of the important things is, it is worth considering a hybrid system with fossils for now. That makes a really good transition. And you've got to be realistic about these things. We know we have succeeded when Rio Tinto and BHP Biliton are part of the team. They are energy companies. They are companies making a profit. They don't want stranded assets. They don't want to emotionally attach to coal. They are running businesses and need to be part of the future. If one can find a transition, then that seems like a really good way to go.
To finish the story, there is a proven process called Fischer‑Tropsch sythesis that takes a hydrogen and carbon monoxide mixture. It goes through quite a few steps. You can take it all the way to a diesel substitute quite easily. Once you have hydrogen and carbon monoxide you can replace anything that petroleum gives us today. You can do all of the reactions and you can create whatever you want. And note this, not only could we maintain our exports, but actually a liquid hydrocarbon is probably worth about three times as much per energy unit as coal is.
So if we value‑add, not only will we be exporting something cleaner, something that people want, we will actually increase our export income potentially.
That is where I will leave you. If we could power all of Japan believe me they would be quite happy with that because they have no energy resource of their own whatsoever. Everything is imported, and 40 percent of it is Middle Eastern oil, and they don't like that. That little square would keep our economy going with knobs on.
There are my conclusions. You are going to hear more and more about CSP [concentrating solar power] technology. I hope you will be hearing more about ANU and Wizard Power and a new dish and power station. I think there is a great opportunity there for us to think big and to think about our export income ‑ and don't buy shares in uranium mines. Thank you very much.
Chair (Kurt Lambeck): Thanks very much Keith for that overview and promising story. I presume you are happy to take questions.
Keith Lovegrove: Certainly.
Question: This is probably a dumb question, but why isn't Australia building PS10s, PS20s [solar power towers] and solar 1s? According to one of your earlier slides concentrating solar thermal only has a 20 to 60 per dollar per megawatt hour price list advantage and renewable energy certificates are trading at the moment at over $40 per certificate. But since Emirates started in 2001 not a single renewable energy certificate has ever been distributed for concentrating on solar power. So why isn't that happening in Australia?
When can we expect a big solar project of the sort you described in Nevada or Spain? When is that going to happen in Australia? How and what (inaudible) enhance that transmission system?
Keith Lovegrove: That's a lot of whens. A little bit of history first. The Emirate scheme, the renewable energy targets scheme under the previous government launched the wind industry in Australia. I think it has done a great thing in that regard. Wind came in because it was the most mature technology. What I'm presenting to you here is the potential for concentrating solar power, but it needs some gigawatts installed before it actually gets down to that price point. Because the Europeans had put in a lot of attractive subsidies, built up the industry to maturity, as soon as Australia put in a market mechanism that mature technology was able to come in and do it.
Now, the targets, when they get around to actually finishing the legislation, is set to grow. Will it be enough to bring in some CSP projects? I think you will see some in Australia in the coming years. But it will probably require co‑funding from things like the New Renewable Energy Development Fund. The first plants won't be competitive. It is going to take quite a while before it is competitive with wind. It has the potential to be though. That's the point I think.
In Spain, for example, they established a feed‑in tariff. They said, we will buy anything up to 50 megawatts. We will buy the output at, I think, 23 euro cents a kilowatt hour. They set it so it was immediately economic to build the plants. Whereas we have gone for a market mechanism, which means we will get the most mature, the most cost effective technology coming in first.
Question: And transmission?
Keith Lovegrove: Well, I think you can build hundreds of megawatts let's say, towards the end of grid lines in various places before you even need to worry about it. Eventually if we were somehow 100 percent solar powered then you would need, rather than everything radiating out of the La Trobe Valley and the Hunter Valley, everything coming in and converging on Sydney and Melbourne and Brisbane, so you would have to reconfigure. There is talk of high voltage DC lines right to central Australia, and maybe we will come to that.
The hot dry rock people, Geodynamics and so on, they would dearly like to see a grid extension so they can access their resource out there in South Australia. If they get their way and that's built, that would actually open up a lot more places to build solar plants.
I think the point of my little graph with the green square is you don't need more places. There's just heaps of places anywhere. So you can probably get by without much grid modification.
Question: Thank you. Martin Green was here a little while ago, last year about October, I suppose, talking about photovoltaics. He kind of had a go at solar thermal, in the sense that he said solar thermal had a limit to the extent to which it could be developed to the efficiencies that it could achieve. And also you had to go and dust it down every now and again because it got dust on it. He was saying photovoltaics has the potential to be developed throughout the century and it could go up to 70 percent efficiencies with nano tech and all sorts of things like that. But there was some sort of magical limit to the potential efficiency of solar thermal.
If you don't mind, I would like to chuck in a second question which is: do you know about the convection tower idea that they had also for Mildura somewhere, and what do you think about that?
Keith Lovegrove: Last question first. I think it's technically possible. I wonder about the economics, and I haven't bought shares in the company yet. They still haven't built it. But it could work.
The PV versus solar thermal thing, I actually think that the PV will go on making progress and they will bring the efficiency up, but more importantly they will bring the costs down. And I think we will reach a point where it makes sense to basically put it on every roof on every house in the country. Where would that leave solar thermal? Well, anything that makes electricity directly is really hard to address the energy storage issue. Energy storage is important.
Solar thermal's big advantage is you can make the energy storage by storing the heat in really simple ways and then your power can be dispatchable. If all solar thermal ever does is all the night‑time electricity, well, that's two‑thirds of it, isn't it.
The other thing is the fuels. The only thing that you can really contemplate if you make electricity directly, well, you can electrolyse water and you can make hydrogen and then there is the hydrogen economy. But every time you do that you are adding an extra step and an extra capital cost and an extra expense to the energy. Whereas, what I'm trying to say here is it is part of the system. You go directly. You go one processing step straight into the fuel and therefore that fuel shouldn't be more expensive per unit energy than the electricity, for example.
So two big reasons why I think it will work: current efficiencies for these plants are around 20 percent convergent efficiency, which is better than commercial solar cells. Where can they go in the future? They can go much higher. He's not quite right. I mean, both PV and solar thermal are actually only, in the end, limited by the temperature of the sun, which fundamentally limits you to about 95 percent efficiency. So we can race to 95 percent.
How do you get solar thermal efficiency up? You build combined cycles. A combined cycle power station is a standard thing. There is one in Darwin. You burn gas. You run a gas turbine. You use the waste heat to run a steam turbine. You get two bites at the cherry and you get the efficiency up.
People have already put small gas turbines on power concentrators. So you have 1,000 degree temperature inputs. You get maybe 20 to 25 percent efficiency out of that. Then you can contemplate a steam turbine on the back of that. Maybe you get up to 40 or 50 percent efficient systems that way. Who knows where it is going to go. I hope that answers it.
Question: Liquid fuels is what you are going to be producing out of that. And the (inaudible) developments in the room there is that it is fine to produce liquid fuels because that is the huge problem for mobility and the high energy use we need to run the economies of the world. But of course whenever you burn that liquid fuel you have greenhouse gases. That problem doesn't go away if we continue to use liquid hydrocarbons in transport for example, however however efficiently it is produced.
Keith Lovegrove: If they come from a biological origin it is a closed cycle and you don't add to the CO2 in the atmosphere; correct. So stainable biomass sourced hydrocarbons burnt is a closed cycle, per say.
Question: Does it give you 100 percent efficiency out of that cycle?
Keith Lovegrove: It doesn't. It doesn't really matter about the conversion efficiency. All of the C02 that was taken out of the atmosphere to grow the plant goes back in the atmosphere when you burn the plant.
If you process coal, what I'm saying there is, it is a compromise. It is a transition. You have got the same pollution you had before but you are stretching it a lot further and you are making a transition. But, yes, it's pollution.
Question: Thank you very much, Keith. It seems that Australia scores 10 out of 10 for its renewable energy science but one or two out of 10 for its political application thanks to the power of the fossil fuel lobby. I remember Sir Mark Oliphant saying, about 30 years ago, that Australia could get all the energy it wanted from the Simpson Desert, but it lacked the political courage to do so.
You may have heard a paper at Copenhagen from Antony Patt saying that the whole of Europe could be supplied with energy from the Sahara Desert with a combination of concentrated solar power and wind power. Surely with our enormous amount of sunshine we could do something similar.
In Europe they proposed a DC current grid and it would cost a hundred billion dollars over a decade, which is about 10 percent of the annual military expenditure. So money isn't a question.
One question I'd like to ask is that of employment. Clearly that's a very important part of the coal lobby, as they have been losing jobs. If we go flat‑out to develop concentrated solar power what would be the opportunities for employment? Second question is: could we actually export electricity rather than fuel by a pipeline over to Indonesia?
keith Lovegrove: Okay. Well, first of all Sir Mark Oliphant was right. Nothing's changed. To go back to your power in Europe from the Sahara, that's starting to happen in a sense, because in my slide of plants currently being built there was one in Morocco. That's not the Moroccans, that's the Germans building the plant in Morocco. In Australia we put in the Bass Link connecting Victoria and Tasmania quite recently. That was standard technology in under‑sea cable.
The distance that Bass Link covers is, I think, less than Morocco to Italy under the Mediterranean. They are starting to build solar plants in northern Africa to power Europe, that's what they want to do. In a sense Spain is almost like a test facility. But there's more sun in northern Africa and about the only thing stopping it, even economically, is the political aspects of it and the stability, I suppose. That will be challenging. So that's happening.
Could you do it in Australia? I'm dubious. You would have to cross the continent, for a start, and then you would have to do an under‑sea link to Jakarta, or are you going to do an under‑sea link all the way to Japan? You could contemplate it.
What I'm actually suggesting is, well, here's a route to liquid hydrocarbon. That's how we move energy around the world today in ships. It seems to work quite well. I'm saying, why don't we put our money on that. Crossing the Mediterranean is quite small. If you put a map of that on Australia and consider our distances, it's much closer than we are to our customers.
Question: Professor, thanks so much for what you have told us tonight. That is really, really ‑ from an ordinary person's perspective ‑ thoroughly warming ‑ pardon the pun.
Keith Lovegrove: Focus your mind.
Question: On the matter of educated self‑interest, the unit that you describe there seems to me not to be needed in a great big acreage block with outward meeting electricity. You could network that all the way across rural areas of New South Wales that might interconnect, that might have onfarm industrial spin‑offs producing bits and pieces or matters of fuel or whatever.
Does it have to be a block unit or can it be spread out, and can landholders across sunlight country get a unit and spin a few dollars?
Keith Lovegrove: Certainly wouldn't be in one block. But I think there is a most economic minimum size. I don't think you'd really want to build it less than about 50 megawatts. Maybe if you have got a remote town you could build a 10 megawatt one, something like that. So, 'yes' is the answer, but within reason. You're not going to have one dish on a farm. I don't think that's ever going to work.
If you have got a farm and you want to do it yourself I think the PV panels are the way to go. But there is still multiple uses. One of the ones that has been kicked around for a long time is actually driving desalination plants. The waste heat from the power generation can actually help drive the desalination. So, yes, there are opportunities, and I think there is great scope for generating income.
I think I missed the question about jobs. The answer is, there are more jobs per unit energy in renewables than there are in conventional ones. That's actually why they are more expensive. So it is very ironic: we can't do it because it is more expensive; and we can't do it because it will destroy jobs, but it is more expensive because you make more jobs. Not only does it make more jobs, but a lot of them would be in remote regional areas. So it has a lot of potential for boosting those economies.
And, yes, site them near processing plants or significant places that need thermal loads and ideas like that. Not one for every farm, I don't think. But some farmers somewhere will get revenue from multiple land use, the same as they do from wind turbines.
Question: You showed a slide of a dish with a PV at the focal point. Could you say a little bit more about how you see that ‑ how that compares with solar thermal specifically? What trade‑offs there are, the advantages and disadvantages?
Keith Lovegrove: It looks pretty good, I have to say. In some senses I'm a solar concentrator person. Wizard Power is aiming to be a solar concentrator company. If someone ended up buying a lot of them to put PV receivers on that would be great too. They are up to about a 30 percent conversion efficiency, so they are very efficient.
If you went completely down that route then you would be back to the same problem that PV has overall. You can't access an energy storage very easily and it is just electricity. But if it turns out to be a winner in terms of the economics of electricity production, then great.
In terms of the scale of roll out, you have one company buying cells from Boeing, I think; very high efficiency cells. There would be limits to the rate you could scale that up.
Whereas, if you jumped straight in at the deep end and you go steam turbines and utility, in a sense it is the least imaginative thing but it actually allows you to scale up the quickest and it has a respectable efficiency as well. So see how it goes.
Question: A question and observation for you to comment on. The question is: I think you indicated you have plants that are now at about 20 years operating life and I presume will go much longer than that. So what is the likely commercial operation life of these things going to be in the future? And the observation is, you have confirmed a view I have had for a while now, that this class of technology generally is going to become increasingly attractive to investors because of the very fast roll‑out and the modular nature of the deployment, which means it can be tracked much closer to the future huge demand curves than some of the classical technologies we have been using, like coal and nuclear, to date.
Keith Lovegrove: On the lifetime one, it's like a car or something. You buy them. They have a certain life. If you want to keep it going you can keep it going forever. When you see cost curves and people say it makes electricity at so many cents per kilowatt hour, what they are doing there is assuming a lifetime, usually about 25 years for the purposes of the economics, and they are amortising the capital cost over that life, dividing by how much energy it is, and that's how much the energy costs.
So you try to do that to all power generating technologies on an equal basis of about 25 years. You try and build your stuff so it will last 25 years. And it is the same with wind turbines. There are wind turbines that are old now. What you are finding is you can keep going if you like. But wind turbines have got better and bigger. If it is a good site it is probably better to just rip it down and put in better ones, just the same as you turnover your car fleet. So 25 years is the short answer.
Question: Just interested in you presenting the bio‑algal diesel as a particular feed for energy. But if it has a solar efficiency of 70 percent, well, why wouldn't you use that as the feed stock for the lot?
Keith Lovegrove: Good point. And it remains to be seen. If algae as a biomass route is a real, real, real winner it could arguably blow all the other renewables out of the water and be it. One of the interesting things actually is that cost graph that showed how in the end all the sensible or technically plausible things seem to come out about the same. It is almost as if there is a law of thermodynamics that says, 'there's no free lunches'.
It is beyond the second law. It's about costs. You don't get anything for free. If something's any good they will sort of (hands waving). I tend to think the algae could come up looking pretty good. Solar thermal is good at really high temperatures for processing things. How would you take wet algae and generate high temperatures? Well, you would have to dry it out. Then you would have to burn some of it in order to gasify the rest of it. It doesn't seem to be naturally good at that.
Whereas the solar concentrator can take the wet algae and the reaction actually uses the water. So the wetness becomes an advantage. You are using the solar to best effect. You are using the algae to best effect. Generally speaking the whole is better than the sum of the parts. Now, we are yet to prove that proposition, but that's what I think is the case.
Question: The economic life of the hole in the ground (inaudible)?
Keith Lovegrove: True. But what you will probably find is that the cost is not in the hole, it is probably in the processing equipment. Because you have to actually gather it up somehow and get it out.
Kurt Lambeck: Thank you very much for that, Keith. I think it has been a very sobering assessment of the possibilities. I would like to thank you very much for your presentation. So please join me in thanking Keith.