To farmers in the dry, windswept Chamwino district in central Tanzania, mangoes looked like a golden opportunity.

With the country's mango industry expanding, 200 smallholder farmers in Chamwino launched a new farming cooperative, AMCOS, in 2013 to establish a foothold. The farmers contributed TZS 30,000 (US$10) each and in return were allotted plots of land, seedlings, trucks and other resources, largely provided with support from the local government.

The AMCOS farmers also received water pumps and a diesel generator to operate them. This was essential, as Chamwino's water supplies had diminished over the years due to overuse, poor management and more frequent droughts. The pumps offered a steady water source.

Man standing near a concrete cattle trough.
Cattle trough built by AMCOS. Photo by Birouke Teferra/WRI

In 2015, AMCOS built a cattle trough and began charging livestock owners for water, bringing in a new revenue stream for the farmers.

But challenges arose. Between rising diesel prices, frequent pump maintenance and occasional breakdowns, the cost of the diesel pump soared, and it was eventually abandoned. The water supply once again became unreliable, and mango seedlings withered. Across the district, farmers reported that only 5%-40% of their seedlings survived.

With hope dwindling, some farmers gave up mango farming altogether. But that was before the solar pumps arrived.

How Solar Power Helped Revive Chamwino's Mango Farms

In 2019, WRI partnered with Tanzania's Traditional Energy Development Organization (Ta-TEDO) to identify areas where decentralized renewable energy could help support agriculture. Through this initiative, AMCOS received funding and assistance to install new solar-powered water pumps with the capacity to irrigate 80 hectares (200 acres) and a drip irrigation system capable of covering 10 hectares (25 acres).

For some farmers, the results were transformative.

With a reliable, sustainable and affordable water supply, mango yields grew. Farmers we interviewed shared that between 2021 and 2022, production more than doubled from an average of around 40 fruits per tree to 97. Those who adopted drip irrigation counted over 120 mangoes per tree the same year. And average incomes from mango sales nearly doubled, increasing from around TZS 150,00 (US$56) to TZS 297,000 (US$112) per month.

Mango farmers in Tanzania.
Women members of AMCOS standing next to a mango tree. Photo by Ta-TEDO

"This solar project has truly transformed our lives," said Suzana Machela, a farmer and AMCOS member. "Our mango production has soared, and we now have ample water for our animals and household. I harvested over two sacks of mangoes, and there's more than enough water to meet our needs."

Along with these earnings came savings. With the diesel generator out of service, watering the mango trees meant hauling buckets of water from distant wells; a grueling task. Farmers and families who did this work themselves saved time and effort thanks to the solar pumps. Those who previously hired help for watering said their labor costs dropped to near-zero with the new drip irrigation.

In addition, AMOCS saved over TZS 2.3 million (US$900) per year on fuel and maintenance by using solar pumps instead of the diesel pump.

Farmers were also trained by TaTEDO experts in agricultural best practices such as intercropping (growing two or more crops in the same area at the same time), which can increase crop yields, use water more efficiently, and reduce the need for harmful chemicals and fertilizers.

"Before this, the cost of irrigation and operations was high, and farmers were unaware of the value of intercropping," says Jensen Shuma from TaTEDO. "Since its implementation, operational costs have decreased, productivity has increased, and farmers have benefited from intercropping, hence additional incomes."

AMCOS Is a Model for Progress — but Bigger Challenges Remain

Chamwino's water shortages are not unique. Growing populations, competing demands and poor water management have strained Tanzania's water supplies, pushing it past the "water stressed" threshold. Across Africa, around 1 in 3 people face water scarcity. And shifting weather patterns due to climate change only exacerbate the problem. In the past 15 years, Tanzania has seen seven significant droughts.

Solar water pumps not only support irrigation but can also help improve local water access. In Chamwino, AMCOS can now sell water from the solar pump to community members during the dry season, reducing the distance they must travel in search of water for domestic use and livestock.

However, solar pumps alone won't resolve broader water shortages. Enhancing long-term water security also requires sustainable water management, conservation, efficient irrigation and better governance.

People sitting beneath raised solar panels near a farm field.
Solar power system installed in Chamwino to power water pumping, irrigation and water systems. Photo by Ta-TEDO

The project also faces challenges that have hampered its potential.

While farmers say they now have better access to water, the solar irrigation system has its limitations. Issues like clogged pipes and insufficient storage capacity mean the system hasn't been able to cover the full 200 acres expected, leaving many farmers feeling excluded. Some left mango farming altogether.

In addition, support resources are still scarce. To expand the cooperative's initial success, farmers could benefit from more training on agricultural best practices, such as irrigation and intercropping, as well as how to use modern farming technologies beyond the solar pumps, like pest management systems or specialized pruning tools. But plans by TaTEDO, the local government and AMCOS to develop a capacity-building network between farmers and supportive stakeholders (via a special purpose vehicle) were delayed.

And there are structural challenges. Most farmers, lacking processing facilities and access to better markets, still depend largely on local buyers, limiting their financial growth.

Related

How to Scale Up Local Success

Local renewable energy offers substantial economic opportunities throughout sub-Saharan Africa. But scaling up these initiatives will likely require overcoming a range of hurdles similar to Chamwino's. Partnerships with government, NGOs and private sector players can help by providing funding and technical assistance to support successful implementation and long-term sustainability.

Specifically, Chamwino's project may benefit from:

  • Policies to address structural challenges for farmers: Governments can support farmers by addressing both sustainability challenges and economic barriers. Policies could focus on mapping water resources, improving management and strengthening governance to ensure long-term water access. Infrastructure investments, such as better roads, can help enhance market access, while measures to combat threats like theft and fires can protect livelihoods.
  • Training for local farmers and clean energy technicians: Agricultural extension programs can help ensure farmers are equipped with modern agricultural techniques to optimize productivity and efficiently manage resources. Strengthening the agricultural extension system with data-driven insights can help tailor training, inputs and technical support to meet farmers' specific needs. In addition, local technicians could benefit from training to maintain and operate renewable energy systems over the long term.
  • Careful monitoring and continuous improvement: Ongoing monitoring helps evaluate performance in real-time and identify areas where system upgrades, such as durable metal pipes and additional water tanks, are most needed to ensure reliable water access and optimize drip irrigation.
  • Better data collection: Baseline information on farmer profiles, production levels and incomes provides a clear reference point to assess progress over time. Data also plays a crucial role in evaluating a project's impact on productivity and community well-being, helping guide future initiatives. Embedding agricultural and related data into regular government surveys and reports could help fill current data gaps.
  • Establishing a special purpose vehicle to channel support: Stakeholders, including the local government, TaTEDO and AMCOS, could accelerate the special purpose vehicle that was intended to help channel finance and support AMCOS farmers with capacity building, market linkages, data management, operational management and more. By fostering partnerships with financiers, NGOs and other stakeholders, the special purpose vehicle has the potential to leverage data, mobilize resources and help scale impact, which could help improve farmers' livelihoods and realize projects' full potential.

Putting Renewable Energy at the Heart of Rural Development

As we look to the future, Chamwino provides a hopeful vision for how renewable energy can transform lives and communities in Tanzania, Africa and beyond. Scaling this success nationally - and internationally - will require all hands on deck: communities, policymakers, NGOs, development organizations and more.

Together, it is possible to empower communities, drive economic growth, and pave the way for a future where renewable energy is at the heart of rural transformation. With the proper support and resources, clean energy can continue to change lives for the better.

Editor's note: This article was corrected on April 10, 2025 to clarify data collection methods. Baseline data on AMCOS farmers' mango yields and incomes was obtained retroactively, one year after the project was implemented. Therefore, there may be recall bias.