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Boosting Desalination with the Sun

Solar power could open the floodgates for desalination, giving people access to clean, cheap water.

ByRachel NuwerNOVA NextNOVA Next
Boosting Desalination with the Sun

“Welcome, this is paradise!” declares Galgalo Abdi, sweeping his arms open in a dramatic gesture.

For a moment, I think he is being sarcastic. This parched swath of wilderness in northern Kenya certainly does not look like paradise to me. In fact, it appears downright hostile to human life. All around us, leafless grey bushes shaped like giant tumbleweeds form a thorny obstacle course, while a few scraggly palm trees sprouting around a bone-dry riverbed offer the only hint of green. All else is orange dust and pale rock, whitewashed by the sun’s inescapable glare.

dry riverbed
Galgalo Abdi and Ibrahim Wario walk to a dry riverbed near Biliqo-Bulesa Community Conservancy in northern Kenya.

Abdi’s earnest expression, however, conveys no hint of jest. To him, this harsh landscape is paradise on Earth—his beloved home.

I’ve met Abdi, a ranger at Biliqo-Bulesa Community Conservancy, at an outpost made up of a few barebone buildings where he and his colleagues live while on the job. Abdi spends his days and nights protecting elephants and other wildlife from poachers and also helping to maintain peaceful relations between nomadic herders who pass through this historically conflict-prone region. He insists that he absolutely loves the job and the place except for just one thing: for half the year, there is no water.

Like much of Kenya, Biliqo-Bulesa receives virtually no rain during the dry season. Although wells here produce ample water, like throughout much of northeastern Kenya, the sulphate-rich soil renders it highly brackish. While it’s less salty than ocean water, it’s still undrinkable for humans. (Elephants, on the other hand, have no problem digesting it and even dig their own wells). Twice a week, Abdi and his fellow rangers drive 45 miles each way on rutted dirt roads to fetch freshwater. The roundtrip journey takes some five hours, Abdi says, and is an unbelievable hassle.

The Biliqo-Bulesa Community Conservancy

As of September 2017, however, he never again had to make another of those grueling runs. His ranger station just became the first site in Kenya to receive a new, ultra-efficient solar powered desalination unit. Each day the suitcase-sized device transforms 211 gallons (800 liters) of salty well water into freshwater. It’s more than enough to meet the needs of the dozen men working and living there, who need about 2.6 gallons (10 liters) of freshwater per day—and to share with visiting nomads, too.

“Before, the water here was not good for us, but now we have very nice water, very sweet water,” Abdi says, leading me to an overhanging porch sheltering two large black plastic tanks. Salt water pumped from the well enters into the tank on the left and, after undergoing reverse osmosis, becomes freshwater deposited in the tank on the right. The whole thing is powered by a few solar panels, situated just above us on the blazing tin roof.

“The machine is very smart,” Abdi says. “It’s helped us a lot.”

To demonstrate, he twists open the tap on the freshwater tank. By this time sweat is pouring down my face and neck, and I eagerly lean over to drink directly from the faucet. Cool liquid fills my dry mouth, indistinguishable in taste from a fancy, overpriced bottled. I would gladly pay money for this water—even if I wasn’t in a desert.

Galgalo Abdi and Ibrahim Wario desalination tanks
Ibrahim Wario and Galgalo Abdi draw water from the storage tanks fed by the desalination equipment.

This small unit is just the first in a grand plan to eventually bring water to thirsty communities throughout arid regions in Kenya and beyond. The program will soon be expanded to a handful of other remote ranger stations, and in January, a much larger commercial unit will be installed in a drought-plagued village near the Kenyan coast.

The project comes courtesy of GivePower , a California-based non-profit organization co-founded by Lyndon Rive, former CEO of SolarCity. Rive initially wanted to bring clean energy to Haiti and other places devastated by natural and manmade disasters, but eventually, the plan expanded to include electrifying communities in developing countries and, now, to bringing clean, affordable water to drought and disaster-stricken places. Traditionally, desalination hasn’t been an option for places like Biliqo-Bulesa because it tends to be expensive to install and energy intensive to run. That may be changing, though.

“The technology is now hitting this inflection point where we can produce water at a much lower cost than you can buy bottled water,” Rive says. “If you don’t have access to running water and you have to travel long distances to get bottled water, then bringing in a clean source that’s a lot cheaper will have a big impact.”

Indeed, whether serving 12 men in the bush or an entire town of 5,000, desalination can free up time, energy and funds formerly drained in the constant search for water.

That has certainly been the case at Biliqo-Bulesa. As Abdi emphatically tells me, “This water has changed our lives.”

Turning Tides

Desalination—the process of rendering undrinkable water drinkable by extracting salt and minerals—is not a new concept. One of the first known references dates back to the 6 th century BCE in the book of Exodus when Moses, confronted with “bitter” water and disgruntled followers, threw in a holy log into the source “and the water became sweet.”

As a modern, scientific process, though, desalination took off in the late 1950s, when engineers developed reverse osmosis membranes. A pump exerts pressure of 600 to 700 pounds per square inch (psi) on salt water, forcing fresh water molecules to squeeze through the membrane, leaving behind a briny discharge.

“The technology is now hitting this inflection point where we can produce water at a much lower cost than you can buy bottled water.”

Today, an estimated 300 million people get some or all of their freshwater from nearly 18,500 desalination plants operating around the world. San Diego , for example, relies on “drought-proof” desalination to reduce dependency on the Colorado River, while Israel has used the technology to transform its nation from water scarce in 2008 to water abundant today, producing 55% of its water from desalination. The results are considered such a success that Israeli scientists are in discussions with drought-plagued neighbors like Egypt, Jordan, and Turkey about exporting the technology, in the hopes that desalination may pave the way for improved diplomacy in the region.

The technology, however, is not suited for every environment. For starters, access to groundwater or seawater is a prerequisite, and desalination can’t be significantly more expensive than other available options. Then there’s the matter of cost and infrastructure. “Will desalination help if it’s the right system of the right size for the right use in the right location? Absolutely it will,” says Yoram Cohen, director of the Water Technology Research Center at the University of California, Los Angeles. “But there’s no such thing as one magic solution that works for all.”

There are ways around those obstacles, however. Spectra Watermakers , the California-based company that manufactured the Biliqo-Bulesa desalination device, specializes in small-scale, energy efficient units that can run on solar power. Originally dreamed up by an avid offshore sailor who wanted such a contraption to use on his boat 20 years ago, the company offers models ranging from a small unit that produces up 40 gallons per day to a much larger one that churns out 14,000 gallons per day—all of which operate on about a quarter of the power required for conventional systems.

solar desalination
A small set of solar panels atop the roof powers the destination device.

The key to that efficiency, says Michael Anderson, an applications engineer at Spectra, is a process called energy recovery. Whereas standard desalination systems immediately release the high pressure brine discharge to the atmosphere, Spectra’s technology recirculates the discharge to help pressurize new water coming into the system by pushing up on a piston pump incorporated into the design. This minimizes energy loss by up to 75%.

Despite the lower cost to run, even the small Spectra units are typically too expensive for people in developing countries to purchase themselves. Instead, any desalination units that do find their way to such communities are usually one-off projects arranged by an individual donor who perhaps passed through on vacation or by a company that installed it in exchange for something—such as the right to drill for oil nearby. But the problem with those kinds of donation-based projects, Anderson says, is that once the unit is installed, it’s usually forgotten about. When it inevitably breaks, it will stay broken.

“When you give someone something but there’s no one around who can fix it, it never works,” Anderson says. “We’ve had cases where we’ve gone to install a watermaker and there’s literally three or four other makers already there in various states of decay.”

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Water, Water, Everywhere

There is, however, another way—which is where the GivePower model comes into play. While small watermakers like the one I saw in Biliqo-Bulesa are being brought in on a philanthropic basis solely to support the men in the field, the large units to be installed in villages are meant to evolve into self-sustaining businesses. That requires both trained operators and repairmen with access to spare parts and a way to make a profit off of the water—meaning it must be competitively priced. GivePower believes their machines, training, and support will satisfy all of these points, and they plan to test that hypothesis with the first large-unit installations at the beginning of 2018.

In addition to providing water to communities, the Spectra machines will save people money by eliminating the need to pay outside companies to truck in expensive water. Whereas villagers current pay 20 cents per liter, the cost of production for the desalinated water will hover around three cents per liter, allowing them to pay just a fraction of what they are currently charged. Meanwhile, they can also charge higher profit-generating prices to outside groups such as the army or navy who seek to purchase their water while passing through.

A nomadic herder stops by the station for some water and a shady spot to rest.

“Twenty-thousand gallons of water won’t satisfy the needs of the entire Kenyan coast, but the demand is so great and the supply is so scarce that the underlying economics look really good,” says Barrett Raftery, executive director of GivePower. “Turning this into a viable business that can make money is the only thing that will enable a solution at a regional level.”

GivePower will cover initial installation and equipment costs for such units, and over the next five years, the community will purchase back the loaned equipment through profits made from the water. After that, all money generated will stay within the community, to be reinvested into building schools, setting up microloan programs, or sending kids to college. GivePower’s financial role in the project is finite, which it argues will allow it to install more units elsewhere.

“The ultimate goal is scale,” Raftery emphasizes. “For us, that means looking at the community as a partner and ground operator.”

That partnership is made all the easier because Biliqo-Bulesa and 32 other communities in northern and coastal Kenya have already formed their own self-governing conservancies, all of which fall under an umbrella organization called the Northern Rangelands Trust (NRT). Not only do the NRT conservancies have a 14-year track record of managing their own resources to the benefit of their residents, but they also put wildlife conservation—which brings in tourist dollars and Western donations—at the heart of what they do.

On the coast of Kenya, says Ian Craig, “freshwater is gold.”

However, rather than install the first large desalination units in the most stable and successful NRT conservancies, Raftery and his local partners instead selected the one that needed it most: Kiunga Conservancy. Located on the coast, Kiunga is intermittently plagued by political insecurity, terrorist visitors from neighboring Somalia, and tribal violence exacerbated by drought. Despite these challenges, in January, a village there will become the site of the first two larger-scale desalination units, capable of producing nearly 5,300 gallons (20,000 liters) of freshwater per day and meeting the needs of 5,000 people. The units, which will run off Tesla Powerwalls, will also mark the first known Tesla products in Kenya.

While the desalination units will not be able to green the arid savannah for improved cattle grazing or to irrigate largescale crops, those involved in the project are convinced of its merits. “On the coast, this technology has the potential to change so much, because the availability of fresh water is a major limiting factor in people’s lives,” says Ian Craig, director of conservation at the NRT. “Freshwater there is gold.”

Raftery also believes that affordable water can make the region more peaceful. Currently, people often compete with each other as well as with wildlife over limited water resources. “Intertribal violence is based on scarcity of resources,” Raftery says. “Extremist groups also benefit from poor quality of life and lack of basic infrastructure there, because recruiting is much easier when people are destitute.”

Mark Zeitoun, a professor of water security and policy at the University of East Anglia, warns, however, against overestimating water’s ability to provide a quick fix for violence-plagued regions. While headlines tend to state that drought leads to conflict, he points out that water scarcity and other environmental issues are generally subordinate to political tensions and asymmetries in power and privilege. “Yes, water is definitely a part of conflict in Kenya as elsewhere,” he says. “But digging a few wells and getting water everywhere won’t resolve anything—except to stop a few people from dying, which of course is a good enough reason to do it.”

desalination tanks ground
Two tanks store water produced by the desalination unit, which is kept inside in a case the size of an old trunk.

That said, Zeitoun adds, “if we get to the point where we can mass produce water through solar desalination at rates competitive to current cheaper solutions, I do think that will be a technological breakthrough that will change the equation for lots of people.”

Whether GivePower, Spectra Watermakers and other similarly-minded ventures can make that happen is yet to be seen. It is the ultimate goal, however. Anderson, for example, imagines sending containers filled with parts to build 1,000 watermakers to various locations around the world through philanthropic funding or a public/private partnership, thus eliminating the need for communities to rely on large-scale municipal projects. “Ultimately, we want the technology to be completely supported and sustained locally, which means assembled, installed and maintained by the community,” he says.

In the meantime, though, the project has at least brought Abdi and his ranger colleagues a little bit closer to paradise.

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Photo credits: Rachel Nuwer, Andreas Kallioras/imaggeo (CC BY-NC-SA) (listing image)

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