- Zero Carbon Australia
- Get Involved
Darren Kimura, CEO of Sopogy, discusses microCSP (micro concentrated solar power)
Posted on 02 Feb 2009
Sopogy is a leader in MicroCSP technologies that bring the economics of proven, large-scale Concentrating Solar Power (CSP) systems to the distributed generation markets. MicroCSP technologies are used to create Process Heat, Solar Air Conditioning or Electrical Power.
Darren Kimura podcast
Scott Bilby: My name is Scott and today we are very pleased to be interviewing Darren Kimura. He is the inventor, president and CEO of Sopogy, a firm that takes traditional large scale concentrated solar technology and uses it on a smaller scale in a form they call microCSP. These systems can produce process heat, for things such as water desalination and food processing operations. They can also produce electrical power, or in combination with an absorption chiller they can produce air-conditioning. Welcome to the show Darren.
Darren Kimura: Hi Scott, thanks for having me on.
Scott: Thank you very much for appearing on the show. Now, how did you first get interested in the whole renewable energy sector and also how did Sopogy get started?
Darren: Sure, I got started in renewable energy in 1992. I was working and living in Portland, Oregon, a very green state in the United States and I got the opportunity to work with the Environmental Protection Agency on a new program they were unrolling at that time called the Energy Star Program. And our job, we were specifically looking for ways to help US businesses conserve energy. So essentially I was going to a large US commercial facility and trying to identify opportunities for them to reduce energy. These things would include reducing your light for example, or implementing a computer-based system to try and monitor and manage your building's energy consumption. Along that line of work, I got into different areas of renewable energy and on-site generation which included things like fuel cells, photovoltaic, thermal energy, which is where we would create ice at night – night time is when the electricity is generally cheaper - and we would use the ice for cool air during the daytime. And that really got me fascinated with the technologies behind the conservation.
So in around 2002 I decided to try and become a technologist and I really became interested in these large scale parabolic concentrators. These are mirrored reflectors that look like a 'C' and these 'C' type collectors would follow the sun all day long. So they were by nature – because they were actively tracking the sun – more efficient. Also they had a very high characteristic for producing a nice firm energy. Traditionally in solar, what we learn is that photovoltaics will produce energy only when the sun is up. So when you got clouds coming in, the energy would begin to drop off. Where as in this concentrating solar power type technology, the systems come with storage and the storage allows the energy to be delivered consistently to the end-user, even in the case of clouds. This was very attractive to me as well seeing as how my whole existence has really been around trying to bring solutions to our customers and to the people we're trying to help with these technologies. So that was in 2002. I had the opportunity to visit a large solar project in California where they were using these large scale concentrating mirrors and following the sun and producing electricity. And I actually tried to bring the technology back to Hawaii, which is where I live.
So I actuality built a prototype collector based on the traditional type systems and learned the hard way that that technology is ideally suited more for areas like the desert and when I tried to bring it into a climate that was a little more humid, certainly a lot more salt in the air because of its altitude relative to the ocean, we had a system that was not very – not able to really withstand the elements. And then the final blow to us was when we had a large storm that came through and it began tossing around rocks. And rocks eventually hit this large mirror which is made out of glass, and began to shatter the glass. So after the storm passed, we were essentially left with nothing – our collector design had been completely destroyed. So in essence, that's what led me to start the idea of Sopogy where I wanted to develop a system that could have the same characteristics of those traditional type parabolic trough systems used in the desert but were stronger, able to be installed in areas like Hawaii, areas where we might have storms or swirling winds, or areas that might have a lot of salt content in the air. So really that's in short how I got from being an engineer all the way to an inventor.
Scott: Well that's quite fascinating and we'll talk to you a little bit about the storage in a minute. But I guess, first of all, for the sake of the audience, you should quickly just explain the name Sopogy.
Darren: Oh that's right, we get asked that question a lot. So the word Sopogy is actually an acronym. It stands for SOlar POwer technoloGY.
Scott: OK good, I think the audience can remember that. It's an intriguing name so I think it's working for you. Now, Sopogy has a microCSP system and I was wondering if you could just explain that in simple terms, for the audience too, before we get started.
Darren: Sure. So the technology, in essence, is a parabolic concentrating collector. And what that all means is we have a big mirror and the mirror is shaped like a 'C' and we follow the sun as the sun tracks throughout the sky. We capture the sun energy by bouncing the radiant energy, if you will the heat, off of these shiny mirrors. We bounce them off the mirror into a tube. These tubes essentially are laid out throughout the middle of these 'C's. And we have a whole bunch of collectors in a field and we circulate a heat transfer fluid – sometime it's water , sometimes it's oil – and we try to raise the temperature of that water or oil as high as we possibly we can. Sometimes we can take it all the way up to steam. Once we create the steam, we can then put the steam into a turbine – very similar to a coal-fired power plant or very traditional power plant and spin the turbine. The key difference here, of course, is that we're using the sun and not burning any fossil fuel.
Scott: And there are also a number of other uses that the microCSP system provides.
Darren: Absolutely, so that heat can be used for things other than creating power. You can use that heat for example, in an agricultural process, where you might be using heat for say drying some kind of produce product. You can use that heat for things like melting metal even, if you can get the heat high enough. The heat can be put into the ground to extract oil or natural gas. You can also use that heat to turn an absorption chiller, which is a thermally driven air-conditioning unit that uses the heat to create cold air or even refrigeration, you can create cold storage with this heat.
Scott: And so, now can you tell us the sort of scale of projects that you're working on?
Darren: Right. So that's a good question and the traditional concentrating solar power systems – we call this industry CSP – has been looking at very large projects. These projects are around 500MW which cover thousands of acres of land in areas like Spain or California. Even in parts of Africa for example. What we're doing at Sopogy – we realise not everyone has the need or the desire for 500 acres of land and 500MW, or whatever the case may be - so we're specifically looking at 1MW to about 20, give or take a MW, of power. So that would be the equivalent size of a hotel or a hospital, even a small utility.
Scott: So you've got some... This is not theoretical, you've got heaps of these systems around the world now, haven't you?
Darren: Oh, absolutely. We've got projects as far away as the Middle East, as far away for me anyway, as I'm in Hawaii, (laughter), and that's on the other side of the world relatively speaking, India, Europe, the United States and Asia. So yes, so these projects, our technology is global.
Scott: Now, so the success of your product – from what I've been reading – you have been really successful and you know, I wish you all the luck in the coming years, well, I don't think you're going to need it actually. But is it to do with the fact that you guys are basically on Hawaii and, you know, it's 3000km off the US mainland and you're pretty remote. The cost of power there, and the cost of everything I guess, is quite expensive. So that would have given you a good basis to actually get a foothold in the Hawaiian market before you started having to worry about exporting?
Darren: Exactly, the entire idea came of necessity. Hawaii imports 90% of its energy and it's all oil. It's all basically oil brought in from areas like Singapore and other places. And then that's refined locally in Hawaii. So that process is very expensive and that gave us rise to the opportunity to try and use the sun which is a renewable and sustainable energy source and convert sunlight or sun thermal energy into power. So how Sopogy really got started way back when I started giving you the example of our first parabolic trough was for a large hotel customer here. They were looking at trying to get off of fossil fuel and they said “Hey, we want you to take a look at this solar area and see if you can come up with something novel,” and that's really what lead us down the path of Sopogy.
Scott: And when did that application, when was that put in place?
Darren: That was put in place in 2002. We got started around 2001 time-frame and we built it all in 2002.
Scott: That's fantastic. And I was reading that the Hawaiian Governor – and is that still Linda Lingle?
Darren: Yes, yes it is.
Scott: She's made a statement earlier in the year the she wants Hawaii to have 70% renewable energy by 2030.
Darren: Yes, it's the most aggressive renewable energy standard in the US.
Scott: That's good to hear and I guess the remoteness is part of the reason she's making that statement – and all those oil importations. But it seems applicable to have those sort of targets in many areas. Now we've previously interviewed Heliodynamics, we may even have done it as recently as last week I think, and they're creating kind of like, a hybrid sort of solution, in producing both heat and power as well. Can you, kind of describe... I'm interested in you describing a little bit more about the most common usage. Would that be in like a shopping centre or something producing both power and air-conditioning as well?
Darren: For Sopogy's technology, it would probably be a little larger than that. So we would probably look to systems maybe as small as like a large shopping centre. Or generally speaking, a large industrial facility, or even a small utility sub-station or a large university campus. Even possibly, like a large hotel or hospital.
Scott: OK. I was looking at the actual product itself. It's a very interesting looking thing and you described it earlier, but apparently you say you can ship that around the world flat-packed?
Darren: Yes, so we took a look at the system from the beginning of the value chain all the way down to the bottom. And what I mean by that is you know, typically technology companies manufacture their products, say in China. They put them in a container and ship these containers all around the world. And that's fine and I mean, from a commerce stand point, it probably makes a lot of sense. But Sopogy really wanted to take a look at the emissions. So instead of going and manufacturing this clean technology in a coal-fired economy, putting it on a boat which would burn diesel fuel and shipping it around the world, thereby contributing this global climate change, you know, crisis we're in right now, we wanted to try and design the systems that could be manufactured locally.
So in order for us to do that, we took everything down to the part and we created very simple and basic parts of our system which include things like ribs. These ribs hold the parabolic shape very nicely. We created longitudinal rails, which allow us to have strength members. So very similar to the human body where you have a spine and a rib cage, our collectors are designed very much like that. Now that, the importance of that design allows us to manufacture the technology in every market in which we're installing the technology. Meaning that for a project in Australia, we would have an Australian company manufacture it. Now those parts are designed to be extremely flat. And we still have some transportation; obviously you might have manufacturing in one city and maybe have to travel several, possibly even a hundred km to another city. So we wanted to create a system that didn't require a lot of dead air, if you will. So we're not shifting a lot of empty space. So the technology is designed to be completely flat. We can palletise them or put them into very nice crates. You put these crates into a container and the container then takes the technology out to a project site. From that point, we've designed the technology and its parts to not require the use of cranes or any other kinds of heavy equipment like forklifts. So you can essentially hand truck up a contractor, a local contractor, to hand truck out the parts and begin to assemble the collectors right there on site.
Matthew Wright: So what's the saving like? If you had to ship them fully built up, how much less... how many more reflectors can you actually ship than if you had to ship them fully assembled?
Darren: Oh a great question. Our density goes up by about 500%.
Darren: So, in other words... yeah, that's a huge thing because the transportation costs of shipping things are very, very expensive. It could be as high as 50% of the entire project cost. So we're 500% more dense in our shipping than a traditional, pre-assembled ship-to-site type collector.
Scott: Now from what I've been reading about your company, that's one of the things I'm very impressed about, is that whole cradle-to-grave analysis. You've really thought about the entire process and transportation is a very good example. I was looking at photos of the microCSP systems and the reflectors are definitely curved. At first I thought they might be flat, but they're definitely curved, and so does that mean you're bending them later when they're constructed on site, or whatever, what's happening there?
Darren: That's a good observation. So, the mirror reflector that we use is actually a flat piece of highly polished reflective metal. And metal is important, this is not your sheet metal or iron or something like that. This is a multi-coated piece of aluminium specifically designed for the solar spectrum, but also coated and protected for an outdoor environment. The importance of having that metal as one is indestructible. So when you have a large wind storm for example, and you have flying debris, if we were using glass, glass would shatter, or glass would micro-fracture and ultimately the glass would not be as reflective and probably break. And the case of this particular material that we use, you don't have any of those issues.
Secondly, it's very, very affordable. This material only cost us about $30/m2 as compared to traditional concentrating mirrors which could cost as much as $100/m2. So we have a nice cost equation in our favour. And then back to your question, these flat pieces of metal are brought to the project site where the local contractor is assembling the collector and we bend the material right there on site and we strap it down with securing straps that allow us to hold and maintain the parabolic - that 'C' shape.
Scott: Now I'll just quick say that we're on Beyond Zero, we're on radio 3CR and the time is 8:47am. Now Darren, Matthew is desperate to know about your storage solutions.
Darren: Good... I'm sorry, go ahead Matt.
Scott: No, that's basically the question. We'll let you expand on that.
Darren: Sure. So that's an interesting characteristic of concentrating solar power that's very different than say for example, photovoltaic with batteries. If you think traditionally, you think photovoltaic or you think laptop with a battery in it. That battery has the ability to store charge for say 2 or 3 hours. That battery might cost you know $200 or $300 US dollars. That's one traditional way to store energy. We call that electron storage.
The more traditional way to store energy of course, would be to put it in a large hot water storage container, like a thermos, or like the hot water storage container that might even be in your home where your using to create hot water during the day time and when you go home in the evening for showers or cooking, or whatever the case is, you would use that water that was created during the day.
Our storage technology is more similar to the latter - it's a thermal energy storage. And the way concentrating solar power stores its energy is we have this oil or water that's circulating throughout our field. So water or oil will then go into these larger storage containers which look very much like grain silos or even to some extent like an oil container - circular with the cap over the top - and these would be insulated. In that container you would have basically hot water or hot oil. Possibly including molten salt which helps you to retain the characteristics of that thermal energy and then as you want to deploy energy, viewed as a form of power, you then pull the energy out of the storage container and use that energy as a fuel to the turbine. So now what happens by doing that, is you eliminate the intermittency that might be caused by clouds. In the case of a parabolic trough you would still have some heat differential because a cloud might come in, your heat would drop off, but it would be made up in the storage container. The energy going into the engine, the turbine, is still at a very firm, fixed rate of deployment. And that's really nice because that storage allows you to buffer, which is what I just described, allowing you to get through cloudy periods of time. But also shift. You could take the energy stored in these large containers and shift the energy until after the point when the sun goes down. You could actually deploy energy from these storage containers, which is sun generated, at night.
Matthew: And that's really good for an evening cooking peak in a place like Hawaii, is it not?
Darren: That's right. In the US there's a lot of utilities that have late afternoon peaks. So, one of the first peaks obviously is during the daytime when the sun is very hot and air-conditioning units spike on. The second peak is when people begin going home and start turning on things like their ranges, or lights or whatever the case is. And the big challenge for the utilities, at least in the US, is to address that second peak. This technology, this storage technology, allows the utility to directly do that.
Scott: Now Darren, I've got a question here now. I'm sure Matt probably knows the answer to this because he's so clued up on this sort of stuff. I'm going to display my ignorance, and one or two members of the audience might not also be aware of this so it might help them to, now you use software to control the microCSP collectors so they can turn upside down if the skies are cloudy or if you've got high wind speeds or if you've got rain and storms. Now it makes sense to me to turn the collectors upside down to avoid rain or damage in a bad storm but why do you need to turn them upside down when it's cloudy?
Darren: Well, you probably wouldn't if it's just cloudy and the clouds were intermittent, you probably wouldn't go into what we call 'Stowe Mode', which is taking the collector and flipping it upside down and having the mirrored surface face the earth. So that's a good observation, we wouldn't go into Stowe, typically when it's just cloudy.
Now if it's cloudy with the chance of say for example rain, then that would probably be a good condition for you to Stowe. What you don't want to have with these kinds of collectors is a lot of rain or possibly even hail, sleet or you know other kinds of...maybe even snow. That may not happen as much in Australia but in certain markets you see that a lot. You don't want to have these parabolic 'C' type collectors filling up with snow. That would be a bad situation for the mirrors. That's what the Stowe Mode - upside down facing to the earth mode - allows us to do is keep the snow off the mirrors and put it on the back side of the panels which is our shield.
Matthew: Now, in terms of Australia, have you identified any market opportunities or started to talk with local suppliers or what you could do here?
Darren: You know, we've been receiving a lot of enquiries on the market. It's not a market that we know very well right now so I think we're, at this point, very keen to get educated and as quickly as we possibly can. By that education then, I think we would be able to swiftly react and potentially even have some technology deployed in that area. I know its a very good area for – certain parts of it anyway – a very good area for concentrating solar technologies, so it is on our radar.
Matthew: I guess we'd say that we've got the best solar resource per capita, per person in the world, so we'd hope...
Darren: ...then we should accelerate this!
Scott: Now, we're starting to run a little bit out of time but I would like to just quickly ask you one question at the end. You had the SopoApps 2008 contest for engineers. Now that was a contest that you guys ran and have the winners been selected yet?
Darren: No, that's a really good question. We have this contest that we're running called SopoApps and you can go to the website at sopoapps.org and our intention there is to create a community of solar enthusiasts, the best solar enthusiasts in the world, and reward them for their ingenuity using solar thermal type technologies. So our plan at this point is to provide the award in March at a conference and of course more information can be found on the site and we look for enthusiasts that include solar hobbyists, maybe contractors, HVAC, plumbing, heating or even university students, to participate in that contest.
Scott: OK, that's fantastic, I'm looking forward to seeing who wins that competition.
Darren: Yes, it's been very well received. We've had over 500 individuals from around the world register to be a contestant in the contest so it's been fun watching the level of interest begin to grow in this area.
Matthew: And I'll certainly submit my fresnel, fixed-bowl design to you. (laughs)
Darren: (laughs) I look forward to seeing that too.
Scott: OK Darren, we've run out of time but thank you very much for joining us this morning, it's been very informative and very enjoyable.
Darren: Thank you for having me. I really appreciate it.
Scott: Thank you very much and we will be looking at how you advance in the next few months and years with great interest because we're very keen on what you're doing.
Matthew: And very supportive.
Darren: I appreciate that. Take care.
Scott: And if you want to know more about the SopoApp 2008 contest, its www.sopoapps.org. Anyway we've been speaking to Darren Kimura, president and CEO of Sopogy, a firm that takes large scale solar thermal technology and uses it on a smaller scale and they call it microCSP. Their systems can produce electricity, they produce heat and produce air-conditioning. So as we said, for more information, visit www.sopogy.com
Transcript by Miwa Tominaga
Beyond Zero Emissions Inc. is a not-for-profit research and education organisation working to design and implement a zero emissions economy for Australia. Its goal is to transform Australia from a 19th century fossil fuel based, emissions intensive economy to a 21st-century renewable-energy-powered clean-tech economy. Read more
Zero Carbon Plans
Buy or Download Free
Zero Carbon Australia High Speed Rail:
Download a PDF here
Zero Carbon Australia Buildings Plan:
Buy hard copies or download a PDF here
Zero Carbon Australia Stationary Energy Plan:
Download the full Stationary Energy Plan here (8.4MB)
Download the Synopsis of the plan here (2.2MB)
Download the Repower Port Augusta Plan here
Download the iPad app here
Download Frequently Asked Questions (1.9MB)
Book a Speaker
Repowering Australia - talks on BZE's vision are happening all around Australia - Book yours today!
Next monthly discussion: Monday 7 April 2014, 6.30pm. Dr Penny van Oosterzee. Fritz Loewe Theatre, University of Melbourne.