Steve Hollis discusses Lloyd Energy System's graphite block storage

Australian company that has created a large scale, low cost, energy storage system based on high purity graphite.

Steve Hollis Podcast

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Scott Bilby: Today we are talking to Steve Hollis, CEO of Lloyd Energy Systems, an Australian company that has created a large scale, low cost, energy storage system based on high purity graphite.

Welcome to the show Steve.

Steve Hollis: Thank you.

Scott: Can you tell us in simple terms what your storage solution system is and how it works?

Steve: Yes, well it is very simple. We are using high purity graphite. High purity graphite has a unique combination of properties simply because the combination of properties in relation to heat storage don’t occur, that graphite has, don’t occur in any other materials, man-made or natural, so it’s an ideal thermal storage medium.

Now the system we have simply collects solar energy via tracking heliostats, which are mirrors that track the passage of the sun across the sky, and focus the sun’s energy in a very sharp image and project that image into our ‘storage block’, we call it. That storage block-does three things. It collects the energy into a receiver which is concentrated and focused into it be the tracking heliostats. Once it is in the block it is absorbed by the high purity graphite and it just sits there until you want to retrieve the energy in the form of electricity. The graphite has conventional heat exchangers embedded in the graphite and when electricity generation is required we simply pass water through the tubes which is like a normal steam blower that makes steam, and that steam drives a conventional steam turbine to create electricity. Really, there are very few moving parts and it’s quite a simple system.

Matthew Wright: Just for our listeners there’s a couple of questions perhaps raised there. So, heliostats I understand are mirrors and so you have many mirrors in a field that focus light on a tower and the graphite block sits on top of the tower. Is that right?

Steve: That’s correct. We’ve designed it as a modular system. As you have probably heard and seen on TV there are a few high tower systems constructed and in operation around the world. They produce steam at very high temperatures and transport that steam off to turbines to generate electricity by the same concept.

The difference between our system and those high tower systems is that those high tower systems don’t have any inbuilt storage. Some of them utilise storage reservoirs for the fluid and some use molten salt as a transfer fluid.

So, storages that are attached to those high tower systems are somewhere else. They’re not in the collection system themselves. They’re taken across and stored somewhere else. That’s the major difference between those systems and our system. In our system the storage is actually at the point of collection of the solar energy.

And also, our’s is on a different scale. Those towers that you’ve seen pictures of are over 100 meters tall. Our towers are only 20 meters tall which is in fact the same height as a rural windmill for example. In fact the towers we are standing our blocks on are windmill towers so we refer to our technology as being on an agricultural scale. So the block, which weighs about 15 tonnes all up, sits on top of this 20 metre high tower and each block is surrounded by 110 heliostats, which are the mirrors. Each mirror is 10m2 in area which means we’ve got approximately 1100 square metres of collection area, of heliostats, directing the concentrated energy into this 15 tonne block.

The block incidentally has 10 tonnes of graphite inside it, so that just gives you an idea of the scale of the system and the whole concept of the system is that it’s modular. Each of those modules occupies about a quarter of a hectare, or an acre, and we can determine the size of the plant that we produce by the number of modules that we have and the size of the steam turbine that’s attached to it.

Scott: Now Steve, just to frame the discussion for the sake of the audience, can you tell us what uses these storage blocks are going to be placed in and how it’s going to help hopefully revolutionise renewable energy in this country?

Steve: Sure, the two projects we are undertaking at the present moment are located in remote rural areas that are at the end, or the outline branches, of the grid. At the present moment, as electricity consumption has increased over the years mainly because of domestic air conditioning, a lot of those branches of the tree once they get right out to the edges of the grid in fact have difficulty supplying power.

So, that brings a number of problems. Firstly there are problems with power quality and voltage fluctuations and the people living in those areas know very well that their digital clocks start to flick and this sort of stuff because the voltages go up and down.

And also, in some areas, the electricity utilities are having to resort to reasonably dramatic and environmentally unfriendly means of boosting the capacity of the system by actually putting diesel generators beside the substation in those remote locations.

This technology simply replaces an alternate generation system so at Lake Cargelligo and in Clonclurry, the two projects on our plate, those projects do three things. Firstly they generate renewable energy, which is a substitution for non-renewable energy. They are at a location where the grid, or the transmission system, is stressed, and it can no longer get enough electricity out there to service the customers. And it also provides what they call ‘network support’, so as the grid starts to struggle, by pushing the electricity back into the grid it stabilises the voltages and so forth and serves a grid support function.

Scott: Now Steve, you mentioned Clonclurry in Queensland, population of about 5,000 people, I’ve read it’s the first town in Australia to depend exclusively on solar power.

Steve: Well, that’s in fact correct. What we will be installing in Clonclurry is a system that will generate 80 megawatt hours a day and it will have a 10 megawatt generator. That means it will have a capability of generating 10 megawatts for 8 hours or 2 megawatts for 40 hours, however your arithmetic works.

So, if the town of Clonclurry is connected to the Mount Isa grid, which is not part of the total eastern Australia grid, it’s just a separate, small grid. The way the plant will operate will, it will actually operate as a peaking plant for 8 hours a day will put 10 megawatts into that small grid. But it will put it in at Clonclurry where the town load is.

If, for some reason, the lines to the generator plant near Mount Isa were cut then it would be capable of supplying the town. At a varying load obviously over the day, but it would be capable of supplying the town independently.

Matt: OK, so it has the higher value when connected to the greater area grid of being able to provide that very important peak power, but in isolation it can actually run autonomously for that town and keep it’s energy security, I guess.

Steve: Yes. Well, in a way, I guess that’s why the technology we have developed has a lot of potential to move forward and replace significantly a lot of non-renewable generation simply because it’s available on demand. The problem with solar energy – in fact solar energy is more expensive to produce than wind energy at the present moment and that’s just a function of the state of technology development. Which means to a grid owner, or an electricity utility, it doesn’t have a lot of inherent value because it’s only there when the sun’s shining, it can’t be used at other times. By applying this technology that we have and having it stored and available on demand the gap between the cost and the value closes because it can be used on demand, it can be used as peaking source and it can be used as a network support function, so the value goes up from say four or five cents a kilowatt hour to ten or twelve cents a kilowatt hour and that’s around about what the generation cost is. So, by having that utility function, or that capability to be available on demand, closes the gap between the cost and the value.

Matt: So, we’ve got this 15 tonne block of graphite sitting on top of a 20 meter tower and you talked about very low losses. Can you tell us a bit about it? It must be super insulated and have opening to allow the light in. Can you explain a bit about that?

Steve: It is insulated obviously, but the secret is that, remember I referred earlier to the properties of graphite and how it lends its use to thermal storage, one of the very useful properties of graphite for this purpose is that high purity graphite, which is crystalline in structure, does not in fact emit radiated heat like other black bodies do for example. Normally, if you remember from high school physics, a perfect black body radiates at a factor of one. Most grey materials of the colour of graphite radiate energy at a factor of about 0.8 - 0.9. Graphite is an odd one because of its crystalline structure it radiates at a factor of about 0.2. That number incidentally is called the emissivity; it has an emissivity of 0.2.

What that all means, getting away from the scientific goobledigook, is that if you have a block of extremely hot graphite and if you put your hand close to it, 50 mm away from it, you actually can’t feel it because it’s not radiating heat. Mind you, if you touch it you might lose your finger! It’s that property that contains the heat. So over a day, and obviously there are some differences with ambient temperature conditions and so forth, over a day our blocks lose about 3 to 5% of the thermal energy heat contained within them. Now that depends on wind and temperatures and so forth, but that’s about the average. So, in other words, if you heated the block up and didn’t take any energy out of it, it would take well over a month to actually just cool down to where it started from.

Scott: The properties of graphite are amazing; I wasn’t aware of that. We are speaking with Steve Hollis, CEO of Lloyd Energy Systems and we’re on 3CR community radio. Now Steve, this graphite storage, do you think it will help solar or wind power get grid parity with non-renewable forms of energy coming onto the grid?

Steve: It’s certainly now very close to reaching pricing parity with alternative energy sources in the solar application. The commonly available forms of renewable energy these days are wind obviously, and I won’t talk much about that because most people know the issues involved, solar energy is divided into two basic categories if you like.

In one category you have photovoltaics which is the direct version of converting sunlight into electrical current and everyone’s familiar with those and you can see them on roofs and places, they’re commonly used now for small scale applications. The problem with them of course is that the electricity only comes out of them when the sun’s shining. So, if you want to make it available on demand or around the clock you’ve got to then take that electricity and put it into a battery because electrons are very difficult things to store and batteries at the present moment, capacitors are really the only way we know of storing electrons. So that’s a severe limitation on the use of photovoltaics as a replacement for baseload power and also the cost at the present moment of photovoltaics, even without storage, is relatively quite high. If you then add the battery storage component it becomes even higher again. So, photovoltaics as a large scale replacement for non-renewable energy - I think we are decades and decades away from that.

However, in the other category we have solar thermal power and of course the major difference with solar thermal power is that heat is much, much easier to store and everyone knows how to store heat, so there’s much more potential on the concentrating solar power side; CSP is the term that is generally used. There are a number of different technologies that concentrate solar power. There’s the parabolic troughs, there’s large dishes, there’s the CFLR which is the Compact Fresnel Lens Reflector system which are a series of flat mirrors across the ground turned at different angles that simulate the parabolic shape.

All of those linear systems, the parabolic troughs and so forth, they’ve got two limitations; or they’ve got one limitation that has two effects. That is, they don’t get to very high temperatures. They get to 300 or 350 degrees. At those temperatures the generation of electricity through steam turbines is quite inefficient, very low efficiency.

The next problem is that the energy is collected in a fluid and you’ve got to take that fluid off into some sort of storage; be it a storage tank for steam or a storage tank for hot water or molten salt, which is also stored in tanks, so you’ve actually got to take it away. But storing it at those low temperatures means that you have to have enormous storages because the storage density is very low.

Now, if you go to high tower systems, and some of the high towers are now coupled up to molten salt systems, they overcome this because they have very high temperatures, say up to 1000 degrees, eight or nine hundred degrees, which means that if you’re generating steam at high temperatures above 350 degrees you have much more efficient electricity generation in steam turbines.

That’s the first factor, and the second factor is that if you can get it in to storage at those high temperatures then storage density is much higher and you can pack a lot more energy into the space. It makes it more efficient and cheaper.

And our system of course, we have temperatures of up to 800 degrees in our blocks, so we’re storing at a very, very high energy density and also we are able to take the steam off at high temperatures and generate electricity using high temperature steam turbines, which again have the efficiency of those two factors. All of that says that concentrating solar power is where we’re going to be going in the future for large scale replacement of non-renewables – using solar energy – for the simple fact that you can actually store thermal energy much more easily than you can any other form of electricity, and also storing it before you convert the solar energy into electricity means that theoretically the storage is almost 100% efficient, whereas most other storages have got an efficiency factor which increases the cost and you lose energy in the process.

So, the future I think, for renewable energy to replace, to make a large impact on our energy generation inventory, the future lies with concentrating solar power plus storage for a whole number of good, physical reasons.

Matt: So, just on that storage, if you do have cheaper sources of variable renewables like wind power, is there potential after hours, as a last resort, to dump excess wind power into the graphite blocks that are already sitting on top of these towers?

Steve: Yes, our technology is available in two packages if you like. We have the solar storage system, which is the block sitting on the tower, but the energy that is produced from a wind turbine is obviously electricity. We have another product, another storage package if you like, which is blocks that are actually heated by electricity, and they sit on the ground, they don’t sit up in the air, there is no need for them to be in the air.

And in fact, we have a project which is being undertaken by a licensee of ours on King Island in Tasmania where that is exactly what they are going to do. There is a lot of wind on King Island and they have a far more wind energy available than they can actually utilise because of the mismatch between the availability of the wind obviously and the demand.

So, what they’re going to be developing there is a system whereby all that surplus wind is transferred into the mach11, or the second type of block that we produce, and stored as heat once again and then re-generated as electricity. So, that’s the second application for the technology; using the wind energy. That’s a market we are also in. As I said that King Island project will be the first of that type.

My point is really though that throughout the world, and particularly throughout developing countries in the world, the greatest potential for penetration of renewable energy into the mix of generation we’ve got now lies with solar power, not with wind, simply because there’s more of it available.

Matt: So, I guess what I was actually asking is it possible to bring the King Island, I guess they’re called resistive elements or resistive coils, the less efficient version using wind power, is it possible to bring that together with the solar tower so that you might have already used some of your heat at 10pm or 11pm and then suddenly you have a burst of wind in the middle of the night and you’ve got nothing to do with it, would it be possible then to make double use of these solar powers and heat those as well?

Steve: In principle, yes. In practice it’s actually better to have your electrically heated blocks just sitting on the ground and then coupling the two steam generation systems together, but in principle yes, in practical terms it would just work a little bit differently. You wouldn’t actually put the electrical energy into the blocks on the towers, you’d actually have a block sitting on the ground and put it (the electricity) into the block on the ground still running the same steam generation system but by two different - machI and machII type - blocks.

Matt: Ok. I guess I was just asking from a perspective of the economics. If the blocks cost quite a bit of money I thought that there might be a bit of value in combining the two.

Steve: Ahh, no, the economics would stack up. What you’d generally find though is that there are not all that many places – we haven’t investigated every place in the world - we have a couple of locations we’ve looked at where we are doing that, for example Norfolk Island. Norfolk Island has both. It has wind and it has solar and we’ve looked at putting the dual system if you like. In fact we put a proposal to the government at Norfolk Island some time ago where we’ve got a dual system, a solar and wind system, where we’re getting the best of both worlds.

Where the best solar resources are in places like Cloncurry and so forth there is actually very little wind, and where the best wind resources are, which is generally around coastlines there is a lot of cloud so the sun is not so good. But where you’ve got a location where you can do both, yes, certainly that’s very viable.

Scott: So, ultimately you could have a dual system but if you have a good solar resource you just go for the solar system on its own because that’s going to be the best solution.

Steve: It will certainly be the cheaper solution, there’s no doubt about that.

Scott: Now, can you tell us about the status of some of your current projects.

Steve: Yes, sure. The Lake Cargelligo project, it’s a project we’re doing supported by the Federal Government through the advanced Energy Storage Technologies Program, from The Greenhouse office. They’ve given us a grant towards that project. That project has physically commenced on the ground now. We are doing site works and so forth, the development applications and so forth are all through council and we are manufacturing all the components for assembly out there.

Our program there is that we’ll put one block up there just so we can do a final check on insolation rates and those other things before we put the next 15 up. So, we’ll have 16 units that plant is designed – it’s only a relatively small plant. It’s 3 megawatts which will operate for a different number of hours in the summer and winter. Mostly that coincides with the peak demands of the network out there.

Once again, it’s capable of supplying the two towns of Lake Cargelligo and Condoblin on its own if it had to, but what we will do is we will actually run it flat out when it’s running and any surplus electricity can just go back down the line into the grid. That project should be, the first module will be completed up there by the beginning of March. The next stage is half the modules up and the steam generator in, running at half capacity by July and then the rest of it about 6 months later. So, by the end of 2009 that project will well and truly be up and running. The Cloncurry project is probably about nine months behind that in terms of the development program.

We have eight other projects under negotiation at the present moment. A lot of those projects though are for off-grid applications for mines that are currently using diesel, where it’s a diesel replacement exercise. Diesel generation is extremely expensive, not as expensive today as it was three or four months ago when the diesel price was much higher, but we’re looking at prices like 40, 50, 60, 70 cents per kilowatt hour for mines off-grid to generate electricity using diesel. So, it’s highly costly and it’s highly environmentally unfriendly. All of the miners, without exception, are now coming to us and talking to us about putting in our system, and we can deliver 24 hour power in remote locations for a fraction of the price of diesel. Even though it’s more expensive than grid electricity, but they don’t have the option of grid electricity.

So, it does two things for the miners. The sort of systems we are talking about, our system and other solar systems, are very, very capital intensive. They’re very expensive to install, very cheap to operate, whereas diesel for example is very cheap to buy and install but extremely expensive to operate. So, the beauty of our system, and solar systems, is that once you’ve got them in 90% of the operating cost, or the production cost, is in fact in servicing the capital. The operating cost is 5 to 10% of the production cost, so therefore to someone like a mining company that says well we have diesel costs that are going skywards and we’re then going to have to meet some form of carbon tax in the future, and that’s an unknown quantity at this stage, so we’ve got a cost curve which is just going upwards.

If we put in a solar system such as ours, we can actually lock in a price, fix it for 20 years and it doesn’t change because we’re simply servicing capital, and that appeals to miners. Same thing to a lot of other users of power that generate power off grid.

The biggest market for our technology, and you’ve seen it happen with Ausra, Professor David Mills’ company, they’ve gone to California where the pricing structures are such there that their solar products are viable and that’s where it’s all happening and for our technology that’s exactly where we’re getting a lot of interest from America. But also of course from Southern Europe where there is a lot of sun, and in Spain and the Mediterranean islands where there is plenty of sun and they have a feed-in tariff for solar energy. So, you haven’t got to go cap in hand to the government to say we want a subsidy for this, it’s automatically there through the feed-in tariff. So, we have a lot of enquires, and in fact some heads of agreement, to do projects in the Mediterranean right now.

Matt: That’s excellent. Just one last question before we have to finish up the interview. Can you tell us a bit about the history of how the idea of this carbon block came about?

Steve: Yes, it’s an interesting story. The name Lloyd Energy Systems comes from the name of Bob Lloyd whose the inventor. Bob came from a background in the power industry and he was obsessed, and we are talking about 40 years ago, he was obsessed by the problems of coal combustion and he always had the view that we are mad because we burn dirty coal and then we try and clean up the mess afterwards. We have ashes to get rid of, we have noxious gases and so forth, and we’ve also got an inefficient combustion system because we’re taking all the rubbish that comes with coal through the combustion, where what we should be doing is cleaning up coal before it goes into combustion.

He did a lot of work over about 25 years and produced a clean coal product which produced coal that was 99.8% pure which doesn’t produce any knocks and socks emissions and has lower carbon dioxide emissions.

You can also put it through a jet engine type generator, a gas turbine type generator, which is more efficient than steam generation plant and it doesn’t produce any ash and residues afterwards, but in 1985 when it was patented nobody knew about greenhouse gases then. Bob was 20 years ahead of it time so it foundered.

So, he used that same process for cleaning coal to clean graphite. His method of production of clean graphite which has got all these beaut properties which we’ve just been talking about, that was the genesis of this technology.

Scott: That’s fantastic. Now the invention of Robert Lloyd is something we are quite impressed by, and we are also impressed by the information you’ve given us during this interview. It’s actually been very informative, so thank you very much Steve for the interview.

Steve: You are very welcome, Scott.

Scott: And I wish you all the luck with future projects and it’s great to see you guys getting into southern Europe and California and getting in there with the real big hitters.

Steve: I might just add there at the end that it has taken a fair bit of money to get to this stage and until we got this last grant for the project none of it’s been with government funding. It’s all been from individuals with a vision for the future, no corporates, nothing. Just individuals who were prepared to invest in it because they believed in it.

Matt: Fantastic.

Scott: It’s a great story for Australia. Thank you very much, Steve.

Steve: Thank you.

Scott: We’ve just been speaking with Steve Hollis, CEO of Lloyd Energy Systems, an Australian company that has created a large-scale, low energy cost, storage system. For more information visit their website at www.lloydenergy.com.

Transcript by Vivienne.