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SunSaluter Purifies Water As It Provides Power

Words by RP Siegel

People have been talking a lot lately about the energy-water nexus, the interdependent juxtaposition of two critical resources that we truly cannot live without. Like two halves of an arch, they depend on one another. Most, if not all of the ways we produce energy require lots of water. Likewise, most of the ways that we obtain clean water require substantial amounts of energy. We cannot preserve one, without preserving both.

Today’s story is about an innovation that is custom tailored for the energy-water nexus. It produces enhanced amounts of renewable energy, while purifying water at the same time. It is actually the brainchild of a 10-year old girl. That’s how old Eden Full was, when she first started tinkering with solar cars. Even at that age she knew that solar panels would be important. She also realized that to be most effective, they would need to track the sun the way that plants do. So she started experimenting with ways to do that.

Less than ten years later, as a Mechanical Engineering student at Princeton, she turned out to be just the kind of innovative spirit that the eccentric tech entrepreneur Peter Thiel, co-creator of PayPal and one of Facebook’s original investors, was looking for. The  20 Under 20 Thiel Fellowship was, in a sense, a $2 million wager that says entrepreneurship is more important than academics.

To prove it, this Silicon Valley Pied Piper offered $100,000 to each of the top 20 applicants who were willing to drop out of school for two years in order to turn an idea of theirs into a business. Eden, who had just spent the summer after freshman year in Kenya, building and deploying a version of her steadily evolving solar tracking system, applied and won. Thus, SunSaluter was born.

I caught up with Eden to talk with her about her journey thus far.

TriplePundit: What are you up to these days?

Eden Full: We are working on the SunSaluter, planning to build our first couple hundred units early next year. We are fresh off our installation in Uganda, Kenya and Tanzania in September. We’ve built out a team. Things are moving forward. I’m pretty excited about where it will go.

3p: So are the units you have installed in East Africa prototypes?

EF: Yes, they are. We worked with the end users in developing the system and we had the financial support of a nonprofit.  It’s been a good opportunity to test things out and to try and figure out a price point for the system. It helped us to understand what people need the electricity for, how they are going to use it and even, if we’re on the right track at all.

3p: So what have you learned?

EF: One of the important lessons I’ve learned, is that for this kind of technology to work in the field, it has to be really simple, especially if people are going to maintain it themselves without technical knowledge. A lot of the people, mostly women, who gather the water and who would be maintaining these devices, have never gone to school. So it’s very important to actually go out into the field to figure out what kind of technology is needed to match that lifestyle.

3p: So what can you tell me about how the device works?

EF: The device uses water flow to rotate the solar panel from one end to the other. We can attach any kind of water filtration system to the panel to clean the water as it flows through. We are still looking for partners for that. At the beginning of the day, you pour in the water, and at the end of the day, it ends up clean in your water filter. In the meantime, it allows the panel to track the sun, giving you 40 percent more electricity than you would get from a stationary collector.

3p: Have you looked at the question of scale, both in terms of balancing the water output with the power output and with regard to the number of people that can be served per unit?

EF: Yes, we are balancing those outputs and we are doing that, at least initially on a unit that is intended to serve an individual family or household, though we could certainly consider expanding that as we go forward.

3p: Are you using some kind of electronics to perform the tracking?

EF: No. The intention is for the flow rate of the water to actually control the rotation. So, by having a physical imbalance, with one side simply being heavier than the other, we can control that without any electronics at all. That goes back to what I was saying before about keeping it as simple as possible. These systems will be installed in locations that are dirty, there are children around, and, of course, there is the maintenance issue. So we don’t want to add complexity. Perhaps, most important, is the fact that by not using electronics, we are able to keep our unit cost down.

3p: How does it perform?

EF: Our tracking system is not quite as accurate as an electronically controlled one would be, but the difference is not significant in terms of the amount of power produced.

3p: So how do you synchronize the movement of the panel with the path of the sun?

EF: By initiating the process when the sun comes up, we can then follow it from there. The simplest devices works the best and we can learn from past devices like water clocks that were used way back when. And there’s a lot that we can learn from the fact that anything that’s absorbing the sun’s energy needs to be able track the sun like a heliotropic plant. We combine these basic principles together to form a new kind of solution.

3p: So tell me about your business model.

EF: People in the kinds of communities we are working with are not willing to pay much for water purification, though they are willing to pay for electricity. They can see the need for electricity to charge their cell phone or provide lighting, better than they see the need for clean water. So by bundling these two functions we can perhaps enable some kinds of water filtration technology to penetrate the market that haven’t been able to penetrate it before. We’re really killing two birds with one stone here and perhaps providing incentive for people to start using filtration who might not otherwise do so.

3p: So what kind of market are you looking at?

EF: If you look at the 1.5 billion people who don’t have electricity and the 780 million people who don’t have access to clean water and if you plot that out on a map, you see a lot of geographical overlap, with many of the same people not having access to either. So, if there’s a solution that can tackle both problems at once without significantly raising the cost, that’s something we really want to push out there and make people aware of.

3p: So how do you see people using it?

EF: You pour the water into the tracker in the morning and you use the solar panels to charge your cell phone, light lights, or whatever. That’s it.

3p: So you pour the water in?

EF: Yes, you pour it in. Many of these communities have to get the water, from a river or from a well. We’re really looking at communities that have access to water. Our added value comes from allowing them to clean their water while they charge their phones.

3p: So your sweet spot is really communities that have water, but not clean water and not electricity.

EF: Yes, that’s right.

3p: As far as the solar technology goes, are you focused on any particular type?

EF: The SunSaluter is adjustable, so any kind of panel geometry would work. We just want to sell it as a component, though certainly we can partner with panel manufacturers.

3p: Are you seeking out strategic partnerships right now?

EF: Yes.

3p: Do you envision that people will use these systems in various configurations like, for example, with a battery?

EF: That’s really up to them and what they’re able to afford. People can pick and choose what they like. But we’re not selling complete systems, not initially. As the business grows, we can adjust out product offerings in response to the market.

3p: Would you consider adding a pump to the system, to pump the water into the tracker at dawn, using excess power from the panel? It could even start automatically when the sun comes up.

EF: Yes, that’s a good idea.

3p: So what is your main emphasis now?

EF: Right now we are just finalizing the design and getting ready to manufacture these first couple hundred units and getting them out there. We are looking for interested partners and communities that might want to reach out to us.

3p: So where will you manufacture them?

EF: Well, this first batch will be produced here, but our plan is to establish manufacturing subsidiaries in the local countries we want to work in. If you look at what people like Paul Polak (IDE) are doing, which is building panels out of mostly local materials; that entails shipping the bare minimum amount of material overseas. That is what we are aiming to do with the SunSaluter as well.

3p: Anything else you want to add?

EF: This first batch is really just to get the technology out there and kind of seed the market. We’d love to talk with interested parties. Our great team has lots of good ideas that are going to be coming out in the next year.

3p: Thanks. I look forward to hearing more then.


Image courtesy of Eden Full.

RP Siegel, PE, is an inventor, consultant and author. He co-wrote the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water in an exciting and entertaining format. Now available on Kindle.

Follow RP Siegel on Twitter.

RP Siegel headshotRP Siegel

RP Siegel, author and inventor, shines a powerful light on numerous environmental and technological topics. His work has appeared in Triple Pundit, GreenBiz, Justmeans, CSRWire, Sustainable Brands, Grist, Strategy+Business, Mechanical Engineering,  Design News, PolicyInnovations, Social Earth, Environmental Science, 3BL Media, ThomasNet, Huffington Post, Eniday, and engineering.com among others . He is the co-author, with Roger Saillant, of Vapor Trails, an adventure novel that shows climate change from a human perspective. RP is a professional engineer - a prolific inventor with 53 patents and President of Rain Mountain LLC a an independent product development group. RP was the winner of the 2015 Abu Dhabi Sustainability Week blogging competition. Contact: bobolink52@gmail.com


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