The Scaled-Down Solar Pump

Published: Apr. 3, 2016

By Mollie Bloudoff-Indelicato for DEM+ND

About Powering Agriculture

Powering Agriculture: An Energy Grand Challenge for Development supports the development and deployment of clean energy innovations that increase agriculture productivity and stimulate low carbon economic growth in the agriculture sector of developing countries to help end extreme poverty and extreme hunger.

Gert Jan Bom has been successfully designing technologies to improve people’s access to water for more than 30 years.

He is the man behind the Volanta community water pump: a simple, low-cost device that was designed in the 1980s and continues to be among the most common standardized hand pumps used low-income, rural communities around the world. Several years ago, Bom took the 30-year-old pump’s basic design back to the drawing board and began working on a model for an irrigation pump for small-scale farmers. But when he blew up his barn near the Dutch city of Rotterdam, he knew his solar-powered prototype needed more work.

“[There was a] cartoon in a national newspaper in Holland of my exploded barn,” Bom jokes. “This happened when I was testing the pump using pentane as a working fluid. A leak developed and the garage blew up.”

Bom is equally lighthearted when he speaks about how he started his career in development engineering (as a way out of the Netherlands’ mandatory military conscription in the 1970s, he says, where he felt training would be as miserable as his experience learning gymnastics as a child)—and of the impact of his work.

“I’m really a one-trick pony,” he says. “I was comfortable with the design of the Volanta pump and went back to that when I decided to build an irrigation pump.”

It took Bom and his team of engineers at the Practica Foundation many design iterations (and one barn) to develop a prototype for what is today the “Sunflower” pump—a solar powered irrigation pump designed specifically for rural, small-scale farmers cultivating less than half of a hectare of land. The machine they built is an environmentally friendly and cost-effective device that is run by a 60-watt photovoltaic solar panel that connects to a direct current motor. The motor uses energy from the panel to turn a large green flywheel that draws water from its source via a reciprocal piston pump. The Sunflower can pump up to 12,000 liters with just six hours of sunlight—enough to irrigate a quarter-hectare plot.

The pump is also highly portable, weighing only 20 kilograms, and its 8-kg solar panel can be removed and stored inside at night for security. The panel can be used to charge small devices, like a mobile phone or flashlight, in addition to pumping water.

Small farmers must choose between expensive fuel pumps and intensive manual pumps to water their land.

Within several months of cracking the design, the team sent 10 pumps to Kenya for field testing. The Sunflower pump officially launched in July 2014 and by early 2015, about 50 units had been sold to Kenyan farmers in an early marketing push by Futurepump, a U.K.-based company that partners with Practica to get the technology to market.

Bom and the rest of Futurepump and Practica have a vision of seeing their technology and similar concepts serving the 500 million small farms that exist worldwide. A large segment of this farming population is composed of people who lack access to many modern services, like piped water, electricity and reliable roads. But small-scale farmers are nevertheless a huge force for global food security: farms of two hectares or less provide 80 percent of food consumed in Asia and sub-Saharan Africa, according to the International Fund for Agricultural Development.

An Unserved Market

In spite of the size and significance of its target population, the Sunflower is among the first renewable energy-powered irrigation technologies to serve this niche of the agriculture sector. Established brands like Lorentz and Grundfos from Germany and Denmark respectively make solar irrigation pumps, but they cater to commercial farmers who can afford to pay for systems costing thousands of dollars. For small-scale farmers in Africa, the options are generally limited to small petrol-powered irrigation pumps and manual pumps.

Image: ASME

Futurepump’s main petrol-powered market competitor is Honda, whose machines are priced similarly to the Sunflower pump, which retails for US$400. Although they move water faster and at a higher volume than the Sunflower, they also lock farmers into recurring fuel costs, which make the pumps prohibitively expensive for low-income farmers to use regularly, especially because farmers need them most in the dry season, when fuel prices are often at their highest.

“The fuel prices are not good for a small-scale farmer,” says Kinya Kimathi, Futurepump’s marketing and partnerships director. Farmers in Western Kenya, where the Sunflower pump launched, spend as much as $10 per week on petrol during the dry season, she explains. That is a lot for farmers who earn roughly $1,000 per year. “If they don’t have enough money to power petrol pumps, they don’t get enough to eat,” Kimathi notes.

Many farmers opt for manual pumps instead. These are less expensive, costing only $150 to $200 each. On the positive side, they have no recurring fuel costs. They are highly labor intensive however, which has a disproportionately negative impact on women and children, who often do the brunt of the work. Kimathi argues that manual pumps contribute to cyclical household- and community-level problems, because they take time away from schoolwork, chores and family life. “Kids are told they cannot go to school until the field has water. It affects communities quite drastically,” she says.

If At First You Don’t Succeed…

In the years Bom spent trying to tackle this problem, he and his colleagues at Practica tried a number of technologies before ultimately settling on photovoltaic panels to power the flywheel pump. They first considered a hot air engine, but rejected the idea when they realized they would not be able to generate the amount of heat required for it to be cost-effective for farmers. It also was not very efficient.

They also considered a glycerine-powered engine. The rough prototype worked by heating the liquid compound in the sun. The expanding and contracting liquid generated energy that could be used to drive the engine powering the water pump. But the team felt that the technology would be too inefficient to consider moving forward with the design.

Bom and the Practica engineers finally decided to experiment with a steam-powered solar design. They assembled thermal collector reflective strips into what looked like a large satellite dish. The thermal strips concentrated solar energy towards a boiler that produced steam, and the steam then powered the engine attached to the water pump.

Image: ASME

This iteration of the pump worked, but it had a few critical problems. Building enough heat to boil water was inefficient, but using an agent with a lower boiling point, like pentane, was potentially dangerous because of the risk of overheating—as Bom and his barn found out. The pump was also too heavy to be moved from field to field, so it could not be shared within a community.

The team tinkered with the prototype for several years and took it for field testing in Ethiopia in 2009 and 2013. But momentum slowed. That is, until the markets gave Bom and his team a boost in 2014, when the price for photovoltaic solar panels dropped dramatically. Futurepump and Practica then scrapped the idea of steam power altogether.

“In March that year, I took another look at the prices of PV solar panels and found that they had dropped to the point that a steam pump could not really compete on price anymore,” Bom says. Once that decision had been made, they had a new prototype ready for testing within a month.

Settling on Solar

When the first version of the Sunflower hit the market, it was different from the other solar pumps that were available. For one, it was priced and proportioned for much smaller farms than other solar pump technologies.

Bom claims it was also more efficient. “Most of the other systems on the market are bulkier, less efficient and much more expensive,” he says.

Part of the reason the Sunflower is lower-cost—and weight—is because it is made largely from plastic molded parts. But it also has unique design features that enable it to maximize efficiency. The pump can lift water from a depth of 7.5 meters, whether that water is clean, dirty or sandy. It can also be paired directly with a low- pressure drip system or optional storage tank to conserve water usage.

The engineers tried numerous technologies before the price of photovoltaic solar panels fell enough to be feasible and affordable.

The first version of the Sunflower also had mechanisms to account for weather changes, which were meant to ensure that the pump operated at maximum efficiency. These included the option to pump manually. It also had a three-step pulley on the motor, allowing the pump to adapt to different solar intensities. This avoided costly electronics, helping to keep the retail price down.

The current Sunflower on the market—version 1.4—includes some improvements over the first version. It no longer has a three-step pulley; instead, it has a two- in-one panel, comprised of two 12-volt modules that are affixed to a common frame. By flipping a switch on the panel, the operator can choose to connect them to the motor either in series or in parallel. On a bright day with plenty of sun, the modules can run in series, which kicks the pump into high speed, turning at about 120 rotations per minute (rpm). On cloudy days, the unit can still operate by having the modules run in parallel. This doubles the current but halves the voltage, so the pump turns at only 60 rpm. This dual power arrangement allows the pump to make the best use of the energy the solar panel provides.

Getting to Market

With sales of the Sunflower pump beginning in earnest in early 2015, the company’s focus for its first year was small farming communities in Western Kenya, along Lake Victoria. The region’s economy was driven by fishing until the industry collapsed from depleted resources. Families turned to farming for survival. This region is where Futurepump feels it can have the most significant impact, at least for now.

Image: ASME

“Smallholder farming is the bedrock of the economy in many areas. The ability to irrigate poses a constraint on production for a lot of small farms, however—particularly in dry seasons. Being able to irrigate the land means farmers can plant extra crops, grow more food and earn extra income,” explains Toby Hammond, Futurepump’s managing director.

Hammond—a U.K. entrepreneur with a career in renewable energy—joined forces with the Practica team after seeing its steam-powered pump in action in a YouTube video. He was so captivated that within a day he was on a plane to meet with Bom and his engineering team. That was five years ago, and they have been working together to refine and introduce the technology under the Futurepump name ever since.

Hammond declined to disclose how many Sunflowers Futurepump has sold to date or what its sales goals are for 2016, but he says that with a full year of marketing now behind them, the company is planning to ramp up sales by working with a network of local distributors. Futurepump decided to switch from direct distribution to third-party distribution in order to remain focused on its technology. That means that in order to reach scale, Futurepump has to harness the expertise of locals. Its plan is to partner with two tiers of distributors to sell the pumps: a master distributor for all of Kenya, as well as regional distributors within target communities.

“The distributors understand the various markets in Kenya. There is no point in redesigning the wheel,” Kimathi says.

Designing a rural markets distribution strategy is a big challenge for product- based companies focused on low- and middle-income countries. Demand has pre- viously reported on the trade-offs social enterprises must confront in choosing whether to manufacture their goods locally or whether to manufacture them abroad and import them. Futurepump made the decision to manufacture the Sunflower in India, in a factory run by its subsidiary, Futurepump India.

Building its pumps in India is significantly cheaper than making them in Kenya, but costs add up in other ways. Futurepump India manufactures Sunflowers and ships them en-masse back to Kenya. Shipping a single 20-foot (6-meter) container from the factory to the port in Mombassa costs about $1,000. The cost is high because the pumps are bulky and heavy and need packaging to ensure they are protected on the two-week boat ride. On the plus side, Futurepump does not have to pay value added tax—or VAT, which is a general sales tax that also applies to imports—because the Kenyan government offers an exemption to companies importing solar products. But collecting this benefit can be difficult because of government bureaucracy and corruption among port officials, Hammond says.

Finally, there are costs associated with “last mile” distribution—getting the pump into the hands of the customers. These include paying for transporting the pumps from Mombassa to the regions where they will be sold, and paying commissions to distributors and retailers. Most distributors expect at least a 30 percent cut of the retail price to stock and sell the product, Hammond says.

The obvious drawback to all of this is that these expenses have to be factored into the final price, which affects the end customer.

“You start off with what seems to be a cheap product, but when it gets into the hands of the consumer, it is easily double the cost. Probably more,” Hammond says. “It is times like these that companies like ours are envious of software companies.”

Looking Forward

Futurepump has thought of ways to make its distribution strategy work in farmers’ favor, however. The company offers a one-year warranty for the Sunflower, and going forward, it will pay a technician to service the pumps once a week for the full year. The regional distributors will handle this maintenance process by working with Futurepump to train local youth to work with the equipment and do the pump inspections.

“We are trying to make the most impact we can,” Kimathi says. “We will train [young workers] to maintain the machines, and by having knowledge of solar equipment, they will be able to get [other] work. This puts education and jobs back into the community.”

Sunflower pump’s maximum daily pumping potential for 6 hours of operation

Sunflower pump’s maximum daily pumping potential for 6 hours of operation. Image: ASME

The main focus for the company however, is building a robust pump that is as low- maintenance and simple as possible. Bom explains that the complexity of the design is similar to a bicycle: an operator can easily to see all of the component parts and take it apart and reassemble it, if needed. The Sunflower has not gone through traditional stress testing, but the Practica team says it ran its prototypes continuously for 250 hours with little issue. Futurepump claims that if used properly, the Sunflower’s panel and pump could last up to 25 years and 15 years respectively.

Futurepump’s and Practica’s continued efforts to strengthen and improve the pump’s design will also bring down costs in the future, making it more affordable for farmers. Version 2.0 of the Sunflower will be largely the same as the current design, but more compact and made of lighter and cheaper materials, Bom says. He adds that that it will continue to be solar-powered so farmers do not have to budget for any recurring costs to use the technology.

The teams also envision developing a range of solar pump designs to fit different customers’ needs. “Having spoken with a lot of different farmers, the settings in which people use the pumps vary,” says Mike Parker, Futurepump’s business development manager. “It would make sense for us to have a variety of choices rather than a one- size-fits-all [product].”

Bom and his team of engineers already have several ideas on the drawing board to cater to farms of different sizes and to pump water from a greater range of depths. Hammond says the specifics of their future designs are confidential at this stage, however.

Futurepump wants to begin research and development for these new models. To do that, it needs to raise funding because, like many young businesses, Futurepump is not yet profitable.

Hammond recounts that fundraising was his primary focus for the first two years Futurepump was up and running. “We weren’t selling [Sunflowers] then because we were doing prototypes, and I was raising money,” he says. The company launched with $750,000 in seed money from the Nairobi-based Africa Enterprise Challenge Fund, which supports businesses dedicated to solving social and environmental challenges in Africa. It has since raised an additional $3 million in grants and loans.

“You start with what seems like a cheap product, but when it gets to the consumer, it’s easily double the cost.”

Now that the company is selling its pumps, Parker says it is trying to raise an additional $1 million to fund R&D, production, marketing and other activities that will enable Futurepump to compete with more established brands, like those making the petrol-powered pumps.

“Those companies have a ton of money and we don’t,” he says.

“But,” he adds, “their weakness is they are not in the [renewable energy] game right now. We are the first, and when you’re the first through the wall, it is always going to hurt a bit. But hopefully we will get to dictate how the market goes.”

Financing Farmers

Until Futurepump reaches a point of growth where it can cut the price of its pumps, it offers a financing plan for farmers who cannot pay $400 in cash upfront. The plan requires a $150 deposit, plus minimum payments of $20 per month thereafter, at an interest rate of 22 percent. The rate sounds high, but it is roughly equivalent to what a local bank would charge for a small loan. (Many of Futurepump’s customers do not have access to bank credit.) Farmers make payments to Futurepump though M-PESA, a popular mobile money transfer service in Africa.

So far, about half of the farmers who have purchased a Sunflower have used the payment plan, and while some have made late payments, no one has defaulted, Kimathi says. Hammond adds that some of them have managed to recoup the costs of the machine from fuel savings alone in as little as nine months.

Futurepump plans to partner with banks and microfinance providers to handle its financing scheme in the future, so it can continue to focus on developing its technology and expanding its reach. After securing a foothold in Kenya, Futurepump intends to introduce the Sunflower pump in Uganda, Tanzania and Malawi.

For the Futurepump and Practica teams, their business goes far beyond selling productive technology.

“When farmers save money because they do not have to buy petrol, they can reinvest that money in their families and in diversifying crops,” Parker says. “Their communities see the ripple effects. When one person does well, everyone benefits. It is bigger than the sum of its parts.”


This case study was sponsored by the Lemelson Foundation. Reporting was contributed independently by Demand’s Contributing Editors.

Related News & Events: 
Futurepump: What Our Customers Say
May. 15, 2017

The Futurepump SF1 solar pump gets excellent reviews from happy users! Hear what farmers have to say about this low-cost, low-maintenance solar pump.