Very few people eagerly await the day that their work becomes obsolete. But Eden Full Goh does. The former Thiel Fellow and Princeton University student has been playing with small solar panels and cars since she was 10 years old. When she was in high school, she “tinkered” her way to a solar tracking contraption that she is now marketing as a transitional technology to help solar energy users in developing communities get the most out of their devices.
Full Goh’s model—called the SunSaluter—is a simple, non-motorized solar panel rotator that follows the sun throughout the day, helping to boost a solar panel’s efficiency by as much as 40 percent. The prototype was conceived in 2008 as her entry project for the Intel International Science and Engineering Fair. Later encouragement from a professor at Princeton and financial support from the Dutch Doen Foundation and billionaire entrepreneur Peter Thiel’s foundation helped her refine the SunSaluter. The device now has a presence in more than 15 countries via Full Goh’s similarly named nonprofit organization.
“Our goal [as an organization] is to spread this design as widely as possible—to serve as an intermediate technology that helps make solar panels more efficient until they become more affordable in developing countries,” Full Goh says.
Approximately 1.3 billion people worldwide lack access to electricity. The majority of the energy unserved and under-served live in sub-Saharan Africa and Southern Asia. They do not have easy access to light when the sun goes down or to reliable means of connecting to the world electronically through radios and cell phones. The energy options that are available to them are often expensive, low quality and even unsafe.
“People living in developing economies expend a lot of energy in the form of manual labor to collect resources for providing (often) poor quality lighting in their homes, for safe and clean water and for charging cell phones,” says Lawrence Matengula of RECAPO Malawi, a community organization that is also SunSaluter distribution partner for East and Southern Africa.
In many regions where the need for energy access is most pronounced, sunlight is in plentiful supply. Solar energy is therefore an ideal source of power where grid connectivity is unavailable or unreliable.
Malawi, for example, is a country in Southern Africa where 85 percent of its 15 million people live in rural areas—only one percent of whom have access to electricity. Because Malawi is landlocked, shipping in and out of its borders is expensive. This means that solar panels are prohibitively expensive for most Malawians, even though prices have plummeted worldwide in recent years. Whereas in some places they may cost US$0.25 to $1 per watt, in Malawi they cost $2 to $3 per watt.
It is places like Malawi that SunSaluter is meant to add the most value. Full Goh’s vision for SunSaluter is to help solar energy become a more affordable option by boosting solar panels’ productivity, and to expand off-grid communities at the same time.
“A lot of energy innovations are focused around how we can optimize grid-connected electricity in developing countries, so there's less focus on off-grid options. Because of that lack of attention, few others are developing technological solutions to solve those problems,” Full Goh says.
Of course, off-grid energy is gaining momentum in many places. There has been a surge of new solar products hitting emerging markets in recent years, with 7.5 million solar lighting products sold in Africa alone in the past five years, according to a 2015 World Bank report. These have provided modern lighting for 37 million Africans, representing a significant improvement, but also high- lighting how strong the need continues to be: nearly 590 people in Sub-Saharan Africa—or 65 percent of the total population—lack access to electricity.
In many of SunSaluter’s target markets in Africa and elsewhere, the need for energy innovation will persist for the next several decades at least. In India—one of SunSaluter’s main product testing markets—Prime Minister Narendra Modi recently announced a goal to expand the government’s solar energy investment so every home can power at least one light bulb by 2019. But with 400 million Indians currently lacking access to modern energy services, there is a clear need for intermediary solutions.
Keeping It Simple
Solar tracking was not a new technology when Full Goh came up with the idea for the SunSaluter. Full Goh stumbled on the concept through her long-standing interest in solar energy and experimentation with how to improve solar productivity.
“One problem that kept coming up was solar panels’ inability to consistently generate the amount of electricity the manufacturer claimed [it could] throughout the day,” she explains. “That got me thinking about why that happens and what are some ways to alleviate this problem.”
Most of the available trackers Full Goh studied used complicated electrical systems that made them expensive and prone to breakdowns. For that reason, solar trackers have not been a viable option for most low-resource communities. Full Goh wanted to change that. Her intent was to build a device that was both affordable and easy to replicate and use.
The SunSaluter’s design consists of a single-axis rotator on which a solar photovoltaic panel is fastened to a hinged frame. One end of the tracker is attached to a weight and the other end to a water clock, which is essentially a unified container with a precision valve. To run the device, the operator fills the water container in the morning and then adjusts the flow of water from the vessel with a control valve. As the water empties out of the water clock and the container gets lighter, the weight balance changes, causing the panel to slowly rotate towards the sun. By the end of the day, the container will be empty, and the solar panel will come to rest facing the sunset.
The SunSaluter also works double duty: the water that flows from the water clock can be connected to an optional filtration system, which then flows into a container, providing users with up to four liters of clean drinking water each day. Although it seems diminutive, it is an important bonus feature of the system given that 783 million people worldwide have no access to safe drinking water, according to the U.N.’s 2012 Millennium Development Goals report. The amount of filtered water from each tracker could satisfy the two-liter per day need for two people; with two panels, a family of four could conceivably have the minimum amount of drinking water it needs for survival.
Although the SunSaluter achieves a lot, the design is so simple that no special aptitude is needed to build it.
“The point of the SunSaluter design is that you can build it even if you don't have any technical knowledge,” Full Goh says. She adds that the system is intentionally uncomplicated in design so it can be built using locally available, low-cost materials. In some places, this might be wood; in others, it might be bamboo or recycled metal.
This flexible design aspect is one reason the SunSaluter is more economical than other trackers. “One SunSaluter costs us about $25 [to make], and we don’t mark up the units by a huge margin,” Full Goh explains. “Some of our past competitors that have gone out of business charged upwards of $600 per panel, because they used complicated electronics to get a maximum power point tracking algorithm in place.”
There are systems that cost less than those, but typically the lower-cost tracking systems still run the end user at least $100, Full Goh explains. This is expensive for many of the SunSaluter’s intended users. “It is also worth mentioning that these [$100] systems are automatic, and so the people who are paying for them can probably afford them,” she notes.
By comparison, the SunSaluter is a fraction of the cost of these trackers, making it an affordable option for those who might not otherwise be able to purchase one.
Building Local Economies
The SunSaluter also has another goal: in addition to being an energy poverty solution, Full Goh’s team hopes that their product will drive local business creation in areas where there are often few economic opportunities for would-be entrepreneurs.
“There are many great technologies, such as solar lanterns, but the only economic opportunity around them for local entrepreneurs is distribution, because they’re manufactured abroad,” says Jake Schual-Berke, SunSaluter’s chief operating officer.
The SunSaluter requires no technical knowledge to build and can be made with whatever low-cost materials are locally available.
RECAPO, SunSaluter’s Malawian distributor, is an example of this vision at work. The organization develops local applications for energy and water filtration in rural communities. Its plan is to sell and install affordable solar electricity and clean water supply systems through SunSaluter.
Matengula calls SunSaluter a “transformational technology” because of how it supports communities by increasing solar panel efficiency and providing clean water at a lower cost than other available methods. His own organization’s operational capacity has been greatly impacted by using the SunSaluter as well: RECAPO’s office had no electricity until the organization started working with SunSaluter. Now, Matengula and his team have a solar panel that is able to light four rooms and the building perimeter and charge their cell phones and laptops.
What allows entrepreneurs and organizations like RECAPO to create new income streams from the SunSaluter is the ability to use locally available materials to build the device. Although Full Goh’s team encourages users to assemble the tracker themselves, SunSaluters can also be purchased as ready to go systems.
“In theory, people want to build it themselves. But [in practice], sometimes it might be too much effort, so some prefer to just purchase it from us,” Full Goh explains. SunSaluter works with several manufacturing collaborators who produce ready-to-go units for sale. Other customers purchase the the tracker’s specialized metal parts directly from SunSaluter as a kit, and then build the core structure themselves.
“We've definitely seen different approaches, but our goal is to help people in the way that they need to be helped, and we have found that different communities have different needs,” Full Goh says. A manufactured SunSaluter kit to hold a small solar panel costs the end user $25 to $30, plus shipping. The smallest version of SunSaluter’s trackers can support panels to power light bulbs for up to four rooms and charge 10 to 20 cell phones, but ultimately the power output depends on the size of the solar panel rather than the size of the SunSaluter, which just accommodates the solar panel’s dimensions.
Users’ other costs include the solar panel itself, which can run anywhere between $60 and $100, depending on the manufacturer and country where it is purchased, and items necessary to make the panel work, like a charge controller, which costs $15 to $30, and a battery that costs between $10 and $30. SunSaluter sells these additional items as part of its kit. It also sells inverters for anywhere between $30 and $50. These are optional, but they enable users with larger, multi-panel installations to power numerous appliances simultaneously.
“Larger multi-panel installations can power a whole house—possibly with some major appliances with an inverter. These would be equivalent to what a lot of individuals have on their homes, which produce a few kilowatts of electricity to power many things,” Full Goh explains. She notes that adding more panels requires more batteries and more robust infrastructure to accommodate all of the components.
For those who prefer it, SunSaluter also makes an automatic model that can support solar panel arrangements of up to 1.2 kW. This model employs a timer that helps the SunSaluter reset itself at the beginning of each day so the user does not have to refill it manually. The SunSaluter team claims that this model consumes 300-times less energy than other motorized trackers.
Results from the Field
Since 2013, Full Goh and her team have deployed more than 150 units in 16 countries, including Kenya, Uganda, Ghana, Tanzania, Malawi, Morocco, Egypt, Mexico, Indonesia, the Philippines, India, Haiti and the United States. The organization says these units have impacted more than 8,000 lives so far.
To study the tracker’s effectiveness and establish a presence in India, Full Goh’s team ran a pilot program with 46 units in partnership with The Climate Group. It distributed 32 manual units and 14 automatic units in rural communities via several partner organizations. SunSaluter then gathered feedback on the tracker’s usability and effectiveness through user and partner surveys and published the findings in a report in September 2015.
The results found that the total number of users for each tracker varied depending on the type of use and community size: some units were used by only one family, whereas others were used by an entire community. Most users found the tracker useful for cooking and improved lighting conditions—studying for example. Eighty-one percent reported having a positive overall experience, while 18 percent of those surveyed reported feeling neutral about the tracker. No one reported negative experiences, though the survey takers believe this may be because the respondents were trying not to offend them.
One important takeaway from the field study revealed users’ frustrations with the manual trackers. Although all of the respondents originally reported having no issues with the device, in a follow up survey, about 40 percent reported that filling the container with water each morning was not a worthwhile effort. The report states: “While most users derived benefit from the SunSaluter, it was not great enough to compel them to practice perfect refilling behavior every day.” The units were refilled 4.7 times per week on average, rather than every day.
One resident of Pariyar Village, not far from India’s capital, New Delhi, was quoted in the report as saying: “The process of filling the water everyday is a little hectic, as I need to do that along with harvesting my field every morning. If the water capacity could be increased to seven days, and I only need to fill the bag once or twice a week, then that would be very helpful.”
As for the partner surveys, most reported that the tracker was easy to operate. Two-thirds said that the SunSaluter-mounted solar panels charged batteries faster than fixed panels. “Those who did not observe faster charging times were not using the SunSaluters correctly,” the report states, which indicated to Full Goh and her team that users may not have received sufficient training.
“For whatever reason, the implementation partner we worked with might not have explained how the system works clearly enough to some of our users,” Full Goh says. “I think all of this feedback has been very valuable for us to assess how we can move forward, how we can improve our training materials and how can we improve the kits we are manufacturing. All feedback is good feedback.”
Most of the partners reported having a positive experience with the technology and 88 percent of them said they believe there is a strong market for it. The SunSaluter team is nevertheless continually working to improve its design and has so far been through about 60 iterations.
An Open-Source Future
SunSaluter also continues working to build its partnership base, with the goal of spreading the product as far and wide as possible. SunSaluter’s team hopes that many of the non-profit organizations and social enterprises it supports will eventually work with them as implementation partners.
What Full Goh and her team have discovered however, is that places with the greatest need for energy access also have the fewest resources to be able to work with an organization like theirs. There are also fewer potential partners in those regions to begin with. These issues have made it difficult for SunSaluter to get started in new markets, and the pace of its expansion has been slow.
"We hope that over time, the SunSaluter will become less valuable, because that will mean solar technology is getting better and that more people are using it."
But Full Goh’s ambition has always been about achieving reach, rather than running a business, which is why she launched the organization as a 501c non-profit. “We structured ourselves as a non-profit because we want to see ourselves becoming less popular over time, not more,” Full Goh explains. “We hope that the SunSaluter will [eventually] become less valuable, because that will mean solar technology is getting better and that more people are using it. It will be a good sign.”
Full Goh adds she looks forward to the day where the SunSaluter becomes obsolete, but in the meantime, she hopes it will stand in as an effective intermediate technology until more manufacturers enter the solar sector, encouraging solar prices to drop further.
She also hopes to see more organizations like hers spreading solar technology, and additional subsidies from governments to encourage growth of the sector. This is already happening with success in a few advanced countries, like the U.S. and Germany. There, solar trackers are already losing their economic benefits.
For everywhere else, the SunSaluter team plans to make its designs open-source, so that anyone can access their technology. Once this happens, the organization will produce a full manual or blue prints for how to assemble the SunSaluter and make these available online.
“We really want to make sure that we are addressing the core needs of communities, and not just rolling in and bulldozing them with our ideas,” Full Goh acknowledges.
She adds, “My approach and my awareness of how things should be done is less about myself and the organization. It’s more about what the problems out there are and how we can provide a solution that will help communities meet their core needs.”