Listen to Podcast
Scott Bilby: This morning on Beyond Zero we’re talking to Graham Ford. He’s the CEO of Heliodynamics, a company based near Cambridge in the UK, and the maker of solar concentrating technologies that convert solar energy into usable electricity and heat, and of particular interest to Beyond Zero is their use of combined solar thermal and photovoltaic technology in some of their products.
Welcome to the show Graham.
Graham Ford: Well, it’s great to be here.
Matthew Wright: That’s great. Are you going to kick it off first?
Scott: Well, the first question I’d like to ask is how did you first get involved in the renewable energy sector?
Graham: It’s a long story in my case. I built my first solar panel when I was 14, now I’m the tender age of 54, so my friends trade jokes about engineers and their obsessions. We set up our company in 2000 and had a vision to reinvent how concentrating solar could work because saw that it was going to be a key part of the, shall we say, ‘beyond zero’ range of solutions that are required.
Matthew: Absolutely, and what makes us particularly interested in your technology is that we’ve spoken to a lot of solar developers, including Australian ones even, who do large-scale solar farms, which is really important to displace that major electricity use that a lot of our industry and homes use, but what you do is closer to source-of-the-energy use and a bit more micro-scale. Can you explain where Heliodynamics’ products are targeted?
Graham: Yes, well we’ve set out to target solutions on a range of scales from what might be called ‘facility scale’ which might be like a school, a hospital, a factory or a shopping mall, upwards. So, a typical smaller-scale installation would be where you need to provide some power and air-conditioning and maybe some heat in winter to a building, and so with our technology you can shade the car-park and use the sun which would usually beat down uselessly on the cars in the carpark, capture that, and convert some of that energy directly into electricity and then the rest of the energy would be collected as heat. Normally that heat is near the boiling point of water. And then we use that heat either to drive a kind of air-conditioning unit called an absorption chiller or it can provide heat for the central heating system in the winter.
Matthew: Ok, so I guess our listeners are familiar with rooftop domestic solar installations where they have either a bit of their roof devoted to solar hot water, so they directly heat water, or another part of their roof they might have devoted to these photovoltaic panels. Now, in your instance, you’ve actually combined those two together…
Graham: We’ve combined them, so if you imagine you could travel down a sunbeam and the first thing that will happen is it (the sunbeam) would bounce off the mirrors that we use, long strips of mirror that focus those sunbeams onto a long thin device called a receiver, and as the light enters the receiver it passes through a glass window and then it lands on the photovoltaic cell. Once it lands on the photovoltaic cell, its energy is absorbed. Some of that energy is used to generate electricity but the rest heats up the cell. So, what we do is we capture that heat and transfer it to water that is flowing through the pipes behind the cells so we get both the power and the heat.
Matthew: Ok, that’s very advantageous. So, also the concentrating element to it, although we do have a company here in Australia called Solar Systems, they’re based here in Victoria, we haven’t actually spoken to any concentrating PV (photovoltaic) people. So, in this case, what are the advantages of concentrating PV over those sort of flat, big, large-scale roof top arrays that we’re used to?
Graham: The big cost in flat plate photovoltaics is the solar cells themselves. They are very hi-tech pieces of silicon wafer that have to be processed - a lot of energy and technology goes into processing that silicon to make the ultra-pure wafer that then forms the solar cell. Now, we use a similar kind of cell technology but we only need about 6% of the area because we are concentrating the sunlight 16 times when it goes into our receiver. So, it’s like having a long thin flat plate PV, but you’ve put it in a very intensely lit zone where the sun appears to be 16 times as strong as it normally is, so you only need 6% of the area and therefore you only need 6% of the cost of the cell and so that transforms the economics of PV production.
Matthew: So, I’ve been reading up on this. There’s high concentrating PV and low concentrating PV. Which one does your product fit into?
Graham: Well, I think we would probably describe ours as high concentrating PV. Low concentrating PV tends to be where you’re just trying to squeeze out a bit more out of a normal flat plate by maybe assembling it with some mirrors on the side to deflect a bit more light onto the normal plate, whereas our cells are especially made for these high intensities. We have a product that runs at 16 suns and next year we’ll also be bringing out a product for larger installations that will actually run at a 100 suns, so we’ll only use 1% of the area of the cell. So, it means that we’re not particularly hampered with the supply of silicon, you know that’s maybe been in the news a bit, where panel manufacturers have actually struggled to get enough wafer. We can get all the wafer and cells that we need.
Matthew: OK, and when you concentrate say one hundred suns obviously you get a lot of heat, but because you’re removing that heat and you’ve got a use for that, you’re not treating it as waste, there’s advantages there too?
Graham: Yes that’s right. There comes above a certain size of project where it’s difficult to get rid of a great deal of heat but for most of our projects we’re able to use the heat. And the sort of applications are either air-conditioning or if you’re say in a desert area near the sea where there is a shortage of water, we can use that heat for desalinating; or we can combine the two, we get cooling and desalinating water.
I mean one of the projects that we’re looking at in Middle East is exactly that where new towns are being created and they have a number of problems; they’ve got to cool them in the intense heat of the desert and they’ve got to provide water, and they’re looking to plan for the future beyond peak oil which is rapidly approaching if it hasn’t got here already, and so they’re interested in solar.
And there are communities in Australia of course that have a very similar combination of problems. I mean, with this technology you could establish whole towns and cities say along the southern coast of Australia where it’s just desert and very little rain. That wouldn’t be a problem. You could build these cities and provide them with water, so it’s a very interesting technology for a desert continent like Australia.
Matthew: Yes, so basically on the tops of many sort of industrial sites and small public facilities such as swimming pools and schools and bottling plants and canneries, you could imagine your systems?
Graham: Absolutely. All these buildings use energy either to make the building comfortable or to power the processes that are housed inside the buildings, inside these factories. At the moment their only choice is to buy electricity produced by coal burning power stations. With solar, much of that electricity could be replaced with solar, solar electricity and solar heat, and so the buildings could become much greener, and add a little bit of storage on top of that and pretty much you can get close to 100% solar powered buildings and processes. And obviously that is an exciting prospect because it’s a real solution that can offer a solution for climate change.
Scott: You’re listening to Beyond Zero. We’re speaking with Graham Ford from Heliodynamics.
Graham, you were just talking about how to get buildings that are close to self-sufficient in their energy requirements. Obviously the buildings would need to have some sort of energy efficiency features included. For example, the installations you’re putting in in the US now and in Greece, are they going to take these places close to being completely self-sufficient?
Graham: Lets take one step at a time. So the first thing that we’re doing is we’re…take the project we’re currently doing in New Mexico, one of their airports. They have a building there and their looking to reduce the amount of electricity that they use for air-conditioning. So, we’re putting in solar-powered air-conditioning that will reduce that load and it will probably reduce it by about 50 or 60%. But of course, that’s a major reduction but it is not 100% yet, but depending on the experience, how it all goes for them, then we anticipate a follow-on project where we’ll be able to take it down almost to zero.
Scott: And with that installation in New Mexico where you’re providing air-conditioning, we’ve spoken to some people in the past where they try and angle the array in such a way that it maximises the amount of sun that they’ll get so that it can closely match those times of the day where air-conditioning is most used. Is that what you do or do you just place the arrays in such a way that you get the maximum amount of electricity throughout the whole year, and heat as well?
Graham: Well, with air-conditioning you get a happy coincidence where the angle of the array that you need to maximise your summer gain also happens to be the way you position an array in order to maximise the annual requirement. So, with our HD 16, which is our 16 sun concentrator, we just run the axis of that concentrator north-south.
For the Albequerque one, it’s about 50 metres long, it’s about 6 metres wide and the 50 metre length runs north-south so the sun rises on one side of it, comes over the top, and sets on the other. And that will allow us to pick up the maximum amount of energy over the year but also maximise the energy gain over summer months when they need the cooling.
Matthew: Graham, Matthew here. I’m looking at a photo of your systems and we have interviewed Dr. David Mills from Ausra. He’s an Australian known to many of our listeners and he uses fresnel technology. We’re looking at your two different models, the very elegant HD10 for applications where the array might be visible to say customers of a hotel or something and the other system, and they look like they use linear fresnel technology too. Is that right?
Graham: That’s right. I’m an admirer of Dr. Mill’s work; a great Australian. His technology is slightly different from ours. With his technology, his long mirrors are just very, very slightly curved and he uses about 24 or so moving mirrors to focus the sunlight on his steam generating receiver.
Because we wanted to work on a much smaller scale, because we wanted to be able to do small projects for individual buildings, we recognised we wouldn’t be able to curve the glass like that because glass is too brittle and it would fracture. So, we needed to take a different approach.
And what we discovered is that we could use individual strips of flat glass and we use about 6 strips of flat glass on each of our heliostats or cradles, and then we use 6 cradles to focus the sunlight onto the receiver. So, you end up with 36 strips of glass moving in these six clusters, or six groups.
Now, what we discovered as we experimented with this arrangement is firstly it gives us very even illumination of the receiver, and that’s great because we wanted to put PV cells in the receiver and they like a situation where they’re evenly illuminated, they work more efficiently. The second thing that we discovered was that we could keep a nice tight focus. In other words, as the sun moves across the sky apparently we get very little spread of the width of the focal line so most of the light any time of day is captured by the receiver, and obviously that was important to get that efficiency right. So, it was a way in which we could take if you like the big idea of Dr Mills’ technology but take it a step further, much further and use it for much, much smaller projects, but even more importantly use it with photovoltaic cells.
Matthew: Now, just before you did mention storage. Now, in terms of what David Mills and some the Spanish, large-scale solar thermal farms are looking at is using nitrate salts and ammonium thermo-chemical (storage). What sort of storage options were you thinking of for localised micro CSP?
Graham: Ok, we like to keep our technology as simple as possible. So, we’ve not wanted to use sort of big tanks of molten nitrate salt. It’s all a bit too difficult for us. So, we’ve taken the view that firstly when you’re air-conditioning the best thermal store is the building itself, but if you need storage it’s very hard to beat for cost effectiveness and safety a big tank of cold water. So, that deals with situations where we are dealing with air conditioning.
Now, for power generation it’s a bit more difficult, and we came to the conclusion that there were really two main sources of storage that we thought were economic and sensible. The first is that on a small scale, there are some new battery technologies around that are reasonably cost effective for night-time storage of power. We particularly like what is known as the zebra battery, which is a hot battery but is nice and safe. It’s made by a Swiss company. It’s still fairly pricey at the moment, but we’re confident that prices will come down over time, and that is suitable for where you want to store say 10 to maybe a 100kWh, or maybe even a 1000kWh of electricity on a big system.
Then at the other end of the scale, we think that for utility scale generation, pump storage is very, very hard to beat, and where you’ve got, like you have in Australia, where you’ve got on the upper east coast where you’ve the mountains and hills there, they’re an ideal environment in which you can set up pump storage schemes, where all you’re doing is your pumping water up the hill during the day and letting it run down at night. And there are ways of arranging and designing those things so that they’re fairly cost effective. And once solar energy becomes a dominant way of producing electricity those type of pump storage schemes will be required. They don’t take up much area, they are environmentally benign, and we think they are probably the best way to go.
Scott: Now Graham, your products operate best at levels of direct sun above 1500 hours per year. In Australia we get about double that on average across the continent. Have you had much interest from people in Australia? Can you see many opportunities here?
Graham: So far, no and I think that it’s because Australia has enjoyed the benefits of being a ‘coal state’. It has had a lot of coal that it could mine inexpensively and produce really quite low-cost electricity. That is changing now that people are recognising that you have to put a sufficiently high price on carbon to change behaviour, to stop burning coal basically. So, what we’re hope is that Australia will take to the technology because we think it’s ideally suited to customers pretty much across the whole country.
Matthew: Yes, it is, as we’ve seen with everyone we’ve spoken to, it’s just really a great place for solar technology!
Graham: Absolutely.
Matthew: And I think partially, also maybe, there hasn’t been much awareness of your type of product, like for us we’re only just becoming familiar with it and I’d say that if we did what we call a ‘vox pop’ where you go into the streets, or if you ask journalists or whatever, they would never have heard of your technology.
Graham: [Laughing].Well, we know that we have a big story to tell and we know that we have a lot of telling to do but we’re very keen to get the word out.
Scott: Graham, does the fact that Heliodynamics was recently purchased by Energymixx, a Swiss company, building and operating large-scale generation capacity from renewable sources, do they give you greater scope to get that message out there to people?
Graham: Our merger with Energymixx has been great for Heliodynamics. It’s given us the resources to move the business forward in a way that we couldn’t have achieved in any other way. It means that we are able to move forward with the demonstration projects that we’re doing and we’re able to move forward with telling the message, getting more interest and getting projects done.
And that’s really what it’s about. It’s about getting out there and getting more and more projects done because I’m passionate that we’ve a whole world to convert from fossil fuels to renewable energy and we know that solar energy’s got to be a big part of that mix.
Matthew: Absolutely. Another thing I’m reading here is you’re using special gallium arsenide concentrating PV technology. Is that in-house or do you get that from a US supplier?
Graham: Ok, I’d like to change the tense of your question. We will be, but we’re not yet. There’s some more development to do in making that gallium arsenide technology work as well as we want and that’s because to be cost effective, gallium arsenide technology needs to work at a very high level of sun intensity, over 500 suns. So, you’re looking at acetylene torch-type levels of heat flow and clearly that’s quite difficult to achieve. We know we can do it but we’re not there yet in terms of being ready to launch a product.
But to answer your question, we’ll be buying in the gallium arsenide technology. We want to stay in the business of making concentrators and we seek to use the best cell technology that is available worldwide.
Matthew: Now, back on concentrators, we mentioned before that your smaller-scale product for say hotel roofs and places where there’s an aesthetic component, now they do look very nice, have you had any feedback on what people think of those?
Graham: Well, everyone we’ve talked to thinks they look very elegant, very 21st century, and we think that for architects who want to be able to design new buildings or refurbish buildings that make a modern statement about renewable energy this is not only a good way to achieve it technically, but it’s a good way to make a statement about the building. So, we are hopeful that architects will take note and start to incorporate our products into the way they design the roofscape of their buildings, because we think the roof and how you design a roof is the key to making buildings zero carbon in the future.
Scott: Now Graham, thank you very much for speaking to us this morning and congratulations so far on all the progress you’ve made. We will be keeping a track on the company and all the implementations that will be happening in the future.
Graham: Well, thank you very much and it’s been a pleasure to talk with you.
Scott: We were lucky enough to be speaking to Graham Ford from Heliodynamics, a UK-based manufacturer of solar technologies that generate useable electricity and heat from both solar thermal and photovoltaics. More information about the company: www.heliodynamics.com
Click
No comments:
Post a Comment