Jerrel Gilliam landed in Sierra Leone in May 2014 ready to start a one-year fellowship with World Hope International (WHI) selling low-cost greenhouses to subsistence farmers whose livelihoods were being jeopardized by unpredictable growing seasons and weather. Gilliam knew the product well: he had spent most of his undergraduate career at Pennsylvania State University working with the Humanitarian Engineering and Social Enterprise (HESE) program to design the very greenhouses he would soon be selling. His task with WHI was to create a market for them in Sierra Leone—the fifth country in sub-Saharan Africa where the greenhouses would be introduced.

Armed with a $500,000 grant from USAID’s Securing Water for Food Program, Gilliam and his local colleagues launched a start-up venture called Greenhouses Revolutionizing Output, or GRO, which would market and sell the greenhouses to individual farmers and cooperatives in Sierra Leone’s northern Bombali district. The project was going full speed until, three months in, Gilliam’s work came to a grinding halt.

“I had to be evacuated because of Ebola. I was the only expat there on the ground—it was really hard to leave the project and all of my colleagues behind,” Gilliam says.

The Ebola epidemic stalled more than GRO’s efforts, of course; Sierra Leone and its neighboring countries’ economies were badly affected by the crisis, and whole communities were torn apart by quarantine, sickness and death. “Many things were handled poorly. For example, schools had to be completely shut down in quarantined areas, but because no arrangements were made for students to make up their annual exams, many students were set back an entire year. There are ripple effects when that happens,” Gilliam explained.

“Technology isn’t a magic bullet. It isn’t automatic. It can help, but people have to invest in learning how to use it.”

GRO is once again in full operation, with Gilliam on its team. The organization's biggest challenge is tackling the ripple effects of the Ebola crisis and, before that, a 10-year long civil war that have crippled Sierra Leone’s agriculture sector—the main source of income for 60 percent of the country’s citizens. GRO’s approach is to help rural farmers by meeting them where they are.

This idea is central to HESE's affordable greenhouses program. As such, every partnership like GRO, implementation approach, and greenhouse is designed a little differently in each of geographic location. This is what the success of any technology depends on, says Khanjan Mehta, director of HESE. “Technology isn’t a magic bullet. It isn’t automatic. It can help, but people have to invest in teaching and learning how to use it.”

Why greenhouses?

Mehta’s team on the greenhouses project has had a long time to learn this. The idea for a small-scale, inexpensive greenhouse first came to Mehta and his students eight years ago. They were trying to identify technological solutions to rural poverty and food insecurity in agrarian societies, like most of sub-Saharan Africa. In East Africa, for example, 80 percent of households depend on subsistence and small-scale farming for food and income. Most do simple, open-air vegetable farming on quarter-hectare plots of land, which leaves their livelihoods vulnerable to drought, pests and fluctuating fuel costs.

Commercial farms operating in the same conditions are able to weather changes more easily because they have better access to sophisticated technologies and financial resources. Greenhouses play an important role in commercial farming, allowing farmers to dictate the climate in which their crops grow and plant year-round, during both wet and dry seasons.

HESE greenhouse size, cost and benefits

The HESE team and its partners believe that small-scale farmers can similarly benefit from greenhouses. “Because [a greenhouse] is an enclosed space, it [allows] farmers to deal with variability in weather patterns a lot better,” says Ku McMahan, from USAID’s Global Development Lab, which funded WHI and GRO in Sierra Leone. “They are able to produce more seedlings that can survive warmer summers and drought conditions. Those can then be planted to improve overall crop production and [farmers’] livelihoods.”

Greenhouse farming also requires less water than field farming, thus improving water conservation—a major issue for the global agriculture sector, which consumes 70 percent of all fresh water, according to the U.N. Food and Agriculture Organization. And it is less labor-intensive than field farming, which can be physically hard on women, children and the elderly.

Most greenhouse manufacturers and distributors cater only to commercial-scale customers and charge upwards of US$3,000 for each greenhouse. They do not sell a product that is size-appropriate or affordable for small farmers. Mehta and his multidisciplinary team at HESE wanted to change that.

When the HESE greenhouses team began field research to understand small-scale farming conditions in Africa, they started by interviewing farmers and agribusinesses in Nyeri in central Kenya. That work in 2009 informed the key parameters HESE uses today whenever it explores a new market. “Our initial design targets were that two people should be able to build it in two days for $200. If it takes more people, time or money, it won’t work,” Mehta explains. The early field team also learned that factors like portability, lifespan and scalability of the structure ranked highly for farmers. With this information, they built their first prototype and began field testing in Nyeri in May 2010.

In most places where HESE’s greenhouses have launched, the total bill of materials ranges from $350 to $500, and each greenhouse retails for about $1,000 because of additional costs like transportation and installation. This may seem like a lot for small-farmers—many of whom earn $2 per day or less—but the amount can usually be recovered in two to three crop cycles, Mehta says.

Perfecting “localization”

The model of greenhouse HESE developed is more accurately called a “high tunnel.” It is comprised of a plastic or wood hoop-shaped frame, a single layer of glazing, and mesh windows for ventilation. HESE’s model measures 5.5-by-6 meters and can hold up to 250 plants. It was designed so multiple greenhouses can be easily connected together to accommodate more plants.

Finding the right dimensions and materials was a lengthy process of trial and error. The design team committed early on to using only inexpensive, locally available materials, but had to build and test multiple prototypes simultaneously to determine which ones could best withstand seasonal changes in each location. To start, HESE tested numerous materials to use for the hoop frame. Wood was initially ruled out as being too heavy, expensive, and vulnerable to warping and termites, and so were PVC plastic pipes for being insufficiently durable and environmentally unfriendly. Another readily available type of plastic piping made of polypropylene random copolymer (PPR), however, was found to be sturdy, recyclable and able to withstand heat and sun exposure.

The HESE team assembled its first greenhouse frames by rooting PPR “hoops” in the ground and attaching them to a central support beam with rebar connectors made of welded steel rods. Wood posts were used to support the central beam. Greenhouse-grade glazing plastic was then draped over the structure and affixed to the frame with bamboo connectors cushioned by a strip of tire. In all, the total bill of materials fell within the $200 budget. (The glazing comprised half of the cost because it was—and continues to be—available only by import.) And the simplicity of the structure meant that it could be easily expanded as the farmer’s productivity grew.

Within two years, HESE’s prototype enabled five successful growing cycles of tomatoes, the team’s test crop. During that time, the researchers also began testing several iterations of the design in Nairobi and in rural parts of Tanzania and Rwanda. Today, HESE greenhouses are being sold in 19 African countries through partnerships with for-profit ventures like GRO.

HESE greenhouse operations and growth plans

As the greenhouses have expanded their reach, they have also undergone redesign, location by location. To do this efficiently, HESE developed a tightly honed “localization process”: its materials list remains fairly constant, but in each new market, the team assesses local supply chains for each material and makes substitutions to optimize for the greenhouse’s durability and cost. “Many people take the approach of building devices based on what is locally available. But what is ‘locally available’ in one place might not be available somewhere else, which is why it is necessary to look deeply into local supply chains,” says Mehta.

Through this approach, HESE ultimately decided to switch from PPR to wood-based frames. The team commits a considerable amount of time upfront to researching wood varieties in each market and selects a wood based on what is readily available, low-cost, and sustainably produced. “This allows us to reduce costs and simplify the materials list, but we have also had to concede a little control over our microclimates,” Mehta says.

In Zambia, for example, the most suitable wood variety is sold in 5m sections, so the team lowered the height of its Zambian greenhouses by 25cm to reduce material waste. In Kenya, the HESE team uses a wood called blue gum, which is inexpensive because it is considered a weed, but it warps, is termite-prone, and can damage the greenhouse glazing if it is not cushioned. HESE has found cost-effective solutions to each of these issues, except the termites. “We realized that it was more cost effective to let the wood and termites co-exist, and then replace the hollowed-out sections every few years,” Mehta explains.

After choosing a wood variety, local climate patterns inform HESE’s design adjustments in each new market, including how high the greenhouse’s mesh windows should be. Mehta describes mesh height as the design’s “secret sauce,” because it affects air circulation within the greenhouse and the range of control over the internal microclimate. It is the only part of the design that is proprietary and confidential to prevent counterfeiting.

If you build it, they will come

Greenhouse technology is new to small-scale farmers in HESE’s target markets, so to help the product to succeed and scale, the team decided early on to pursue a business-centered approach to implementation.

“We knew that as an academic program, we could not go at this alone—there would have to be a lead entity in each place,” Mehta says. HESE therefore opted to license its technology to other organizations. It takes 10 percent cut of its partners’ sales.

A greenhouse should be possible for two people to build in two days for $200. Any more people, time or money and it won’t work.

Taking the lead on finding HESE’s sales partners, Mehta says he looks for individuals who will take a “brutal, market-based approach” to creating demand for the product. “You can be a brutal business person and find ways to integrate people who cannot pay into your business model. But it doesn’t work the other way, if you’re an NGO, and you see everyone as a beneficiary,” he says. “I don’t want [partners] for whom this would be second or third priority. I want people who will give up everything in life to sell these greenhouses and support the farmers.”

Roland Fomundam, CEO of Greenhouse Ventures, is one of those people. He formed Greenhouse Ventures in 2012 to license the technology from HESE and launch it in Cameroon. To introduce greenhouses to local farmers, Fomundam and his colleagues tried an unconventional approach: they built greenhouses for their own use, grew crops, and took the produce to sell in the local market. “We focused on creating as many different types of produce as we could,” Fomundam says. “Based on what we produced, [farmers] could see the [potential] return on the investment if they owned a greenhouse. This helped the market understand the value.” Farmers began approaching Greenhouse Ventures’ sales team to learn more about how the technology works.

To encourage more direct community engagement, Greenhouse Ventures also installed greenhouses near orphanages and involved the children in growing crops, and it gave several greenhouses away to local universities and community groups. Fomundam describes all of these efforts as necessary to building interest. “To catch a fish you need bait. We knew we would not be making money in the first year, so everything was an investment. [By] now, honestly, we have a demand we aren’t able to supply.”

Mehta says HESE’s partnership with Greenhouse Ventures has worked out so well that HESE recently expanded the organization’s licensing rights to three more countries in West Africa, including Nigeria and Ghana. But not all of HESE’s partnerships have had similar success. The program’s original licensee in Kenya was given sole licensing rights to 10 countries in East Africa, but these were scaled back to Kenya only when the entrepreneur stopped prioritizing sales over growing his own produce. Meanwhile, it took GRO a long time to gain momentum in Sierra Leone—partly because of the Ebola crisis, but also because local attitudes to small-scale farming imposed enormous barriers for the technology.

“There just isn’t much of a tradition of agribusiness in Sierra Leone,” Gilliam explains. He compares agribusiness in the country to Guinea, where most of Sierra Leone’s produce comes from. “In Guinea, farming is a very robust tradition and is seen as a way of making money and improving one’s lot in life. Subsistence farmers in Sierra Leone don’t see farming as something that can bring social mobility or a secure future. It’s a difficult [attitude] to encounter when you’re trying to [work in] these communities.”

After a tumultuous first year, GRO has shifted its market development strategy by focusing building relationships with secondary schools and university agriculture programs.

GRO sales and support model

Obstacles to access

Each partner uses different strategies to account for its local social, economic and agricultural environments. Yet, many of the challenges they face are similar, says Alison Padget, vice president of programs for WHI, which has now implemented over 50 greenhouses in three countries: Sierra Leone, Mozambique, and Zambia. “You’d think the challenges would be distinct, but they’re not,” she says.

Most organizations are confronted with infrastructure challenges, for example. “[In] these countries, there’s a lack of access to water, and there are poor roads, so everything is tough to transport.”

“There’s also just a lack of support for farmers in general,” Padget adds. “If you have a crop that fails, there’s not necessarily an extension agent like you would have in the U.S. who will come test your soil and provide advice and tell you what pesticide to use. A lot times you’re on your own.”

As difficult as the work is, Padget says her organization has seen the positive impacts of introducing farmers to greenhouses. For example, WHI helps women’s farming groups band together to purchase greenhouses, because the increased productivity of greenhouse farming can have a direct impact on each woman’s household income, she says. Greenhouse installations have also resulted in increased water-savings and reduced pesticide use, as well as growth in seedling yields. Padget recalls one entrepreneurial farmer in Mozambique who discovered a market for seedlings, which he sprouts in his greenhouse and sells to neighbors who do not have access to quality seeds. “I want to say he made something like $8,000 in one crop cycle, which is enormous because we were expecting three crop cycles to pay off the cost of the greenhouse,” she says.

One challenge that HESE and its partners have yet to figure out is how to help farmers finance their product, which ranges from $700 in Kenya to $1,000 in Mozambique and Sierra Leone. So far, most farmers have relied on their own financial means or special agreements with the seller. But lack of access to financial services, and particularly credit, is a limiting factor to the greenhouses’ ability to scale.

Microfinance seems like an obvious solution, but Mehta reveals that most greenhouse customers avoid microfinance lenders because lenders’ interest rates are too high. “The rates for microfinance loans in Kenya, for example, are obscene—30 to 40 percent interest. I can’t think of one farmer who has purchased a greenhouse on an MFI loan,” he says.

“Financing is definitely a challenge,” he continues. “In Zambia, we crowd-funded our first five greenhouses, but farmers need so much support that cost recovery is very difficult.”

In GRO’s case, Gilliam admits that it would have been impossible for the organization to keep its prices in Sierra Leone at $1,000 without grant funding from USAID and its partnership with WHI, because of the high cost of building the market. Now, WHI and GRO have helped 21 greenhouses get off the ground in Sierra Leone. Gilliam believes future demand will be strong, largely because the demand for fresh produce is strong.

“There is a lot of risk that people will sell solutions that will mislead people who cannot afford to be misled.”

“Most of the produce currently sold here is imported from Guinea. There is massive room for growth in local agriculture production,” he says.

Being able to prove market growth and earning potential to farmers is important, given the number of low-cost agriculture technologies that are emerging, promising positive impacts for the world’s farmers. “[New technologies] have to be able to demonstrate that they are successful,” Gilliam says. “Many new technologies are built up to be something that they aren’t, and that can be harmful. There is a lot of risk that people will sell solutions that will mislead people who cannot afford to be misled.”

Nevertheless, Gilliam feels that its important to encourage the development of affordable products for low-income farmers. “There is a lot of room for affordable technologies to grow. It is not going to be a clean road, but it is the right road,” he says.

Mehta adds that the amount of time it takes to launch a new product is an automatic filter for unviable technologies. “It takes five to seven years to start to see any evidence of scalability. A project like this doesn’t happen overnight. It requires tenacity and persistence. If you don’t stay on it, you’ll never get anywhere.”


Jessica Pothering is business journalist focusing on social innovation, finance and economic development. Her reporting and research topics range from social impact bonds in the United States to social entrepreneurs in Southern Africa. She started her journalism career covering finance and now serves as Demand's managing editor.

Sara Goudarzi is a Brooklyn writer and holds a master’s in journalism from New York University and in bioresource engineering from Rutgers University. Her non-fiction has appeared in National Geographic News, The American Scholar and CNN.com, as well as Scholastic’s Science World Magazine, among others.