Peter Le Lievre from Chromasun discusses solar powered air-conditioning

Using concentrating fresnel technology in combination with photovoltaic solar cells, Chromasun's solar modules harvest the sun's energy in the form of both heat and light for air-conditioning, power, process heat, and lighting. Primarily for commercial installations, a product launch of these roof mounted units is due sometime in 2010.

Chromasun CEO, Peter Le Lievre discusses the details with Beyond Zero's Matthew Wright and Scott Bilby.

Peter Le Lievre from Chromasun discusses solar powered air-conditioning

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Scott Bilby: This morning on Beyond Zero we’re talking with Peter Le Lievre. He’s a co-founder of Ausra, which was formerly Solar Heat and Power. Listeners will know from our previous interviews with David Mills that Ausra is a utility scale solar technologies company. Well, Peter, he’s now formed a company called Chromasun and they’re developing air conditioners.

Now you might think, hang on a minute, he was producing lovely sustainable renewable energy from the sun one minute, now he’s producing air conditioners and they squander a lot of energy. Well, Chromasun’s different. Their air conditioners use the sun’s heat to actually create a cooling effect, and so it looks like one way of helping reduce the huge amount of greenhouse gas and the cost of air conditioners that emit all that energy on sticky, hot afternoons.

Anyway, good morning Peter, it’s nice of you to join us from the US. How are things going?

Peter Le Lievre: Oh, good thanks. Good morning Scott, Matthew, Ian. Yeah look, you’re completely right. I was one of the founding – CEO of Solar Heat and Power and Chromasun and that company went on to do great things in the United States as Ausra. But as the company grew I wanted to get back to doing what I love best which is start-ups and we soon had more than 100 employees, which made it a very busy place. At the same time I could see that it was actually quite difficult to get the electricity that we were generating out in the desert into the cities where it was needed. There’s a lot of grid congestion in the United States, in the big cities in California particularly, as there is in Australia I might say.

And when you look at where the grid congestion’s coming from, the peak electrical loads are coming from air conditioning on those stinking hot summer days when everybody’s got their air conditioner turned on. And most of the grid, most of the generating capacity of the utility system, is designed to try and handle these peaks loads at those few hours of the day when everybody’s trying to keep cool.

So, you know, our company Chromasun was spun out to try and solve that problem by taking what we knew about concentrating solar power and making it available on rooftops so that we could help drive air conditioners directly from solar thermal energy and reduce electricity consumption. And the nice thing about that was that if you look at peak electrical loads, say in Los Angeles on a hot summer’s day, nearly 50 per cent of electrical consumption is going into air conditioning, when I traveled through the Middle East in the United Arab Emirates, Dubai, for example, has 70 per cent of peak electrical load is coming from air conditioning.

So we felt that this product was going on the rooftop of commercial industrial buildings, able to supply heat directly to air conditioners such as they could then run chillers to provide the air conditioning without any electrical consumption and without requirement of utilising the grid to try and transport even more electricity from outside in the desert into the cities, you know, the grid already being overloaded during those periods and periods at any time. So that’s what we attempted to do and that’s the reason we founded Chromasun.

Matthew Wright: Now you obviously know a lot about all the different solar technologies and our listeners have heard about the different approaches, but you seem to have stuck with the linear fresnel approach that came out of University of Sydney and University of New South Wales. Can you tell us why you thought the linear fresnel approach is the best for the job?

Peter: Sure. Look, linear fresnel is a very elegant technology for generating what I call medium concentration, and medium concentration is sort of anywhere between 10 and 50 suns, where you’re concentrating the sun’s energy between 10 and 50 times. And that allows you to generate temperatures sort of comfortably and sort of the 100 Celsius up to about 350 Celsius range which is a good range for a lot of industrial processes, including driving steam turbines for electricity generation and also for, in this case, driving absorption chillers which run at about 170 degrees Celsius.

And when you look at the spectrum of solar technology you can see that you’ve got what we call the high concentration technology such as dishes and fresnel, or two axis fresnel systems, which are quite complicated but do get you 600 to 1000 times concentration. But, you know, for most industrial process heat applications we think the 20 to 50 sun range is more economical and cheaper to produce, and at the end of the day makes it a more reliable, easier to own product than the high concentration technologies do.

So, I’ve always been a fan of it and in this medium concentration space I think when we look at say parabolic troughs or we look at other ways of generating that sort of concentration I think the linear fresnel is quite elegant. You know, it has a high mirror cover over the ground, it’s quite simple to produce, easy to track, and probably one of the nicest parts of it is that the receivers, you know, the steam pipe or the photovoltaic cell or the bit that actually collects the concentrated sunshine, it sticks, it doesn’t actually have to move. And that allows you to sort of plumb it in with pressure piping and you don’t need any moving joints or anything like that. And so, again it just adds to the simplicity and makes it a low cost system. So that’s why we use linear fresnel.

Matthew: Now looking at the website, so the unit is fairly modular and it’s about 1.2 metres wide by 3 metres long. Is it sort of designed to come out of a mass production factory so that the complete units can then just be assembled in a modular way on site at the customer’s premises?

Peter: Sure. I mean, we’re treating this exactly the same as a regular solar collector, which you might put on your roof to make your showers hot or to heat your pool or that sort of thing. And those come pre-assembled, pre-manufactured and just get mounted on the rooftop. And that differs quite strongly with the say the large CSP technologies which tend to have to be constructed or manufactured on site, which, you know, putting people out in the desert, trying to keep them healthy and safe and yet performing a manufacturing job is quite difficult to do. So manufacturing the product in a regular factory and then shipping it out to sites simply to bolt down is a good way to do it.

The second key difference is obviously this is only a small collector – you know, 3 metres long by 1.2 metres across, and yet has all of the features of the large CSP systems, the fresnel systems that we built at Ausra that, you know, covered a whole football field. So what we’ve tried to do is put all the technology that we had from the large CSP system but make it available on the rooftop in a pre-packaged, pre-manufactured collector that is easy to install and is easy own and operate as a regular what we call a ‘one sun collector’, you know, that you would put just to run your shower and that sort of thing.

Matthew: Yeah, so our listeners might know about those, and might know that people on their roof have, say, a flat panel system with a bit of toughened glass on top and underneath there might be some copper pipes and the sun radiates down and heats that. The alternative of course is the evacuated tube systems. Now with the Chromasun system, could you describe that, like what, how’s it packaged? How’s it covered and what’s inside? How many linear mirrors, linear reflectors are inside? Things like that.

Peter: What we’ve tried to do is put the concentrator inside, under glass and so with a regular one-sun panel you’ll have as you said the glass and then you’ll have a copper plate which is just illuminated directly by the sunlight and then that copper plate is welded to a copper tube which then takes the heat away. And because you don’t have any concentration, because, you know, the illuminated area is illuminated just directly by the sunlight, they can’t attain very high temperatures because the hotter they get the more, you know, the heat wants to escape again.

Now what we’ve done is use the same glass box if you like but put a linear fresnel concentrator inside which meant that it’s away from the dirt, it’s away from the wind, it’s away from the rain. And it’s made it quite reliable because it’s not being affected by the environment, yet we can make a track and have those moving components that we need for a CSP-type technology, but being inside the box can do it in a way that you can put on your rooftop and not have to worry about any moving parts or anything on the outside. The box itself just stays fixed, fixed on the roof as a regular flat paneled collector would.

Matthew: Now, inside it has photovoltaics, so that’s also the other kind of thing that we know we see on people’s roofs, and they’re those solar electricity panels that people feed their power back into the grid and perhaps get a feed-in tariff with. So you’ve actually combined the heat and the electricity production in the box?

Peter: Sure. Yeah, we’ve utilised some Australian National University technology where they’ve managed to develop a solar cell which is based on a standard reliable silicon cell which is well understood and well known – available in regular photovoltaic panels for your roof. But they’ve managed to adapt that cell so that it can perform at a 25-sun illumination, so that it’s able to generate a lot more power with the concentrated sunlight.

And then their hybrid nature is that we then mount that cell onto what we call a receiver with a coolant running behind which allows us to take all the waste heat away which you would normally throw away. So when you look at, say, a regular photovoltaic panel that might be, say, 15 per cent efficient on your rooftop, that’s the same as saying it’s 85 per cent inefficient because it’s throwing away the other 85 per cent of the energy gathered from the sun as heat.

Now what we do is we get that 15 per cent efficiency collecting electricity and then we also harvest the other 85 per cent as heat and then make that available on the rooftop for, you know, solar processed heat applications in the building that the panel is mounted on.

Matthew: Now, one more thing about the box, inside the box, how many and how wide are they, of these linear reflectors there are, like we’ve all seen the pictures of the Ausra plants with their really big metre-wide or whatever reflectors and….

Peter: OK. Well if you look at an Ausra collector, it’s, you know, it’s a big CSP-type system. It’s a 100-foot aperture and it’s up to 1000 feet long. And it’s all focusing on a single line receiver, which travels also 1000-feet long. And the key number is that it runs about a 25 to a 35 times concentration ratio between the light that’s collected and the light that’s focussed on the receiver. We run a similar concentration ratio, but our effective aperture is only about 600 millimetres on each of the optics, and we have two of those optics in a single box. So we have two 600 millimetre apertures side by side and two receiver lines running the full three metres of the box. And that gives us a total of about six metres of receiver and about four and a half square metres of collector area for each of the MCT (Micro-Concentrator) units.

Matthew: Yeah. And what’s the effective efficiency of the PV component versus say regular panels on a roof?

Peter: Ah, it’s about the same. It’s a little lower, depending on the temperature that you run it at. The cells themselves are running at actually a higher efficiency than you would get on a regular PV panel because one of the nice things about silicon cells is that they actually improve their efficiency when they get more sunlight put on them. They seem to perform better. But on the negative side we have to get the light through the glass into the box reflected off the mirrors accurately and then finally collect it up on the PV receiver and each of those steps means that we lose a little bit of energy along the way. And so our effective, what we call ‘aperture efficiency’ of the box, is sort of around 10 to 12 per cent, whereas the regular photovoltaic panel might be, you know, 13, 14, even 15 per cent, so a little bit lower but still well within economically valuable range.

Matthew: And because you’re using a lot less material, does that mean your costs should be lower in that part of the project?

Peter: Yeah, of course. We’re using 95 per cent less silicon than a regular panel. Our optic, or our reflectors, are extremely light because there’s no wind in there. So they’re also very low cost. So the overall material consumption of this part of the collector we believe is quite a breakthrough in terms of low cost. So we’ve been able to price the unit on a dollar per watt basis, or we will be pricing on a dollar per watt basis, more competitively with photovoltaic panels even as they come down in costs throughout 2009, 2010.

But at the same time we’re offering, you know, the rooftop owner the ability to collect all of that heat as well in the same unit. So they’re getting, if you like, two products in one – a photovoltaic panel and also a solar cell collector all in the one unit.

Scott: We’re speaking to Peter Le Lievre from Chromasun and the time is 8:46 am here on 3CR community radio. Peter, now the cost effectiveness of these units compared to, when they’re up and running, how are they going to compare to, you know, conventional electric or gas powered air conditioning units?

Peter: It depends on the installation. I mean, we’ve been focusing mainly on what we call commercial industrial customers running larger installations. And that’s shopping malls, that’s, you know, data centres. These are building loads that are several hundred kilowatts up to several megawatts of cooling power required. Now, in those big installations they run what we call double effect chillers which are very efficient and when powered by solar thermal energy are able to produce a lot of air conditioning with not that much solar thermal energy required. And the economics means that we can offset quite a bit of electrical consumption that would have occurred had that same air conditioning load been satisfied with a regular what we call a mechanical chiller, a chiller that’s driven by electrical energy.

And when you do the cost comparison of buying all of that electricity versus doing it with the solar cell method you find that the two are actually quite equal to each other, but when you factor in the what we call feed-in tariffs or subsidies that are available for producing green air conditioning or reducing electrical consumption by offsetting with green technology then it’s actually quite lucrative to use these types of solar thermal systems to drive air conditioning.

For example, we’re looking in California at about a three or four year payback on systems like this, which is actually quite a good economic return for a solar system. And in Australia, although we’re in the early days of the economic assessment, it looks like we can generate subsidies for both the solar thermal aspect and the electrical aspect, such as payback, might be between six and eight years.

Matthew: And do you see any possibility that you could also market these into consumers at least to do, you know, your solar hot water, because at the moment many households sort of haven’t really quite got the room. They’re competing for space on the roof as to whether they have their photovoltaic electric generating system or their solar hot water service, but they don’t have room for both.

Peter: Yeah. I think there’s two parts here. One is that there’s a limited roof space, and the second is it just looks awful. I mean [laughs], you know, you see a house and, yes they’ve got the great photovoltaic panels and then right next door they have the solar thermal system, and it just, they look totally different on the rooftop whereas our product is a single panel that requires half as much roof area as what we were just talking about and also happens to look quite attractive at the same time.

So, yeah, I think ultimately we will move into the residential market with our product. Although, initially because we’re in this large what we call ‘maxi-panel’ format which is ten feet long, it’s probably a little big for most people’s homes initially but later, when we come out with what we call our second generation of products, you’ll see them smaller and more customised for residential use and we certainly hope to penetrate that market as we grow.

Matthew: What would you do with the heat in the residential situation if it wasn’t quite big enough to drive chilling, or would you actually be able to have air conditioning as well?

Peter: I think more likely in residential applications you’re going to see low grade heat supplements. So we’ll be doing all the reticulated hot water in the building - showers, washing, that sort of thing. And if there’s any pool heating or any sort of low-grade industrial or processed heating to do in the property we can do that as well. But I guess one of the challenges we have is that we actually have a lot of hot water to get rid of, so you could have almost endless hot showers with a system like ours whilst you were generating electricity at the same time.

But we will be looking for large loads, as large as we can get, in these residential applications. Pool heating is certainly a very good one - that allows us to dump a lot of heating in the pool.

Matthew: Scott’s looking pretty excited and I think he’s wondering – in the commercial set up – what actual temperature do you get? Because we found out you’re talking 25 times the – 25 suns ratio from the reflectors. What sort of temperatures are you working with and how do you transfer them around? Are you transferring the heat around as air or in an oil fluid or as water?

Peter: Look. The nice thing about using CSP or linear fresnel is that we can easily get to 200 Celsius which is about the right zone to run double effect chillers. We are using oil in our initial systems, although we can though just heat water directly. But the oil is nice because it allows us to store it easily in the plant room in the building in an oil tank that allows us to stretch our capacity factor or to go on into the night with the air conditioning. And it also allows us to generate these higher temperatures without worrying about high pressure steam in the building and, you know, having to deal with the boiler code and having boiler attendants running the air conditioning system. So at the moment that’s the format, it’s a collector. It runs for about 190 to 200 Celsius and it’s heating up heat transfer fluid or oil which then goes into the plant room to drive the double effect chilling.

Scott: Now Peter, I’d like to know just how close you guys are to commercialisation of this product.

Peter: Well, we’ve been going about a year now. We’re a classic start-up. Start-ups are quite common in the United States, particularly in Silicon Valley where we’re based. Obviously when we started Solar Heat and Power back in 2002 it was less common here and the company began in the garage in Artarmon and now it’s one of the biggest CSP companies in the world. But we’re a start-up and we’re currently building what we call our data test units, which is our first production-like units which we are putting into what we call showcase projects. One showcase project is an air conditioning company in Dubai and we’re presently securing another showcase project probably in San Jose, California, also with an air conditioning company there.

So, you know, based on how the showcase projects go we’ll be raising money to expand our manufacturing capacity and then probably see a product launch into 2010 I’d say, sort of Q1 (quarter one) maybe Q2 of 2010 you’ll see us start to sell units in the general wholesale or industrial markets.

Matthew: And will Australia likely go to market at the same time as the US or be a bit behind?

Peter: Well, we’re delivering two products. One is what we call a thermal only which is for these high temperatures and one is what we call a hybrid product, which has the photovoltaic receiver. The photovoltaic receiver, because it’s coming from Australian National University, we’ll probably launch that here later in 2010 as a direct Australian product launch. At the moment we don’t have any concrete plans for that date but it seems most likely that it will be an Australian launch of that. And at the same we’re also pretty active looking for a showcase project for our thermal product in 2010 as well. But it’s early days yet and we’ll see.

I’m sure there’ll be a ready market in Australia, but we haven’t made any concrete steps to satisfy that market just yet.

Matthew: And, can you tell us a bit about the actual factories and the manufacturing process, would there be an opportunity to manufacture with green jobs in Australia?

Peter: Yeah, I think so. It’s what I call a low or medium technology product. It’s not a high technology product. It doesn’t require a $300 million dollar factory to be able to build it. In fact, it can quite readily be built with the sort of manufacturing skills and technologies that are readily available in Australia. Particularly, you know, if we look at, say, the car industry in Melbourne and in Adelaide. I mean, a lot of the sub contract suppliers of components in that industry will be readily able to supply the components that we need to build our products.

So, one of the nice things about solar is that they’re difficult to ship [laughs]. You know, they’re hard to build in say China and then ship all the way across the world because they’re quite big and they occupy a lot of space. So you’ll tend to see local manufacturing set-ups supplying the local markets and our product is designed to be what we call ‘contract manufactured’ in the markets that we’re in and we’ll certainly be selling a contract manufacturing capability up in Australia when we launch in that marketplace.

Scott: That’s great to hear. Now Peter, we’re running out of time, so do you have any closing statements you’d like to make about the product?

Peter: Well, look, I’d just like to say that I think solar is extremely big in Australia. You know, it’s been a vibrant and active research community for many decades, and the fact that Solar Heat Power and Ausra became as successful as they did is simply because Australian technology is that good, and I feel staunchly Australian even though I’m operating out of California at the moment with these companies.

I just, I see the challenge for technologies in Australia as the limited ability of venture capital and support for start-ups to allow these technologies to be commercialised. So, you know, I look forward to coming back to Australia and bringing some of that know-how back with me and bringing Chromasun back as an example of how successfully you can commercialise Australian technology, in this case from Australian National University, when you have a good venture capital model.

I wish us luck with that, but hopefully we’ll see a lot more of it as we move into the next few years. Particularly with the current federal government and strong interest in supporting renewable technologies.

Scott: That’s great to hear Peter. It’s great to hear that, you know, because Australians really do need to know that there are great inventions that Australians have played a part in, and yes, they have commercialised these things overseas and it looks like we’re going to see another one appearing quite soon in the name of Chromasun, so thank you very much for talking to us.

Peter: You’re welcome.

Scott: We’ve been speaking to Peter Le Lievre from Chromasun. They’re developing air conditioners that contain both photovoltaic and solar thermal technology. And, obviously, they harvest both the light and the heat from the sun to cool the space and also produce electricity if you would like that too. You can learn more about Chromasun by going to www.chromasun.com

Transcript by Jenny Gibson