Pumping Life with Solar Power into Zimbabwe’s Small-Scale Farms

In Zimbabwe—like in many African countries—rain-fed agriculture is increasingly becoming unsustainable due to recurring and severe climate change-induced droughts.

The occurrence of drought in Zimbabwe has increased significantly, from approximately once every decade a few years ago to once every three years. This has affected nearly 70 percent of Zimbabwe's population, who still depend on rain-fed agriculture or rural economies.

Today, many small-scale farms lie abandoned as droughts are becoming severe. Dense bushes, mostly sickle shrubberies have taken over some of these farms. Last year, Zimbabwe was ravaged by a devastating El Niño-induced drought, the worst in over 40 years. The drought wiped out most of the farmers' summer crops; it killed millions of livestock, and left nearly 7 million people in Zimbabwe without enough food.

However, buoyed by low-cost solar-powered water pumps—also known as photovoltaic water pumping systems—some innovative small-scale farmers in Zimbabwe are now able to irrigate their crops and eliminate the need for rain-fed agriculture. According to experts , the use of solar energy to power groundwater pumps by farmers in drought-ridden, off-grid regions in Africa and elsewhere has been heralded as potentially revolutionary.

One such farmer, Alford Chadambuka, a small-scale farmer in the Zimunya area in eastern Zimbabwe, is now harnessing a photovoltaic water pumping system to irrigate his crops. These crops include the maize, the country's staple crop, tomatoes, and various leaf vegetables.

"With my solar water pump, I’m able to grow crops throughout the year. Sadly, my current crops were destroyed by stray cattle, but I'm hoping to start planting some tomatoes soon. I just want to fix my fence before planting the next crop; otherwise, I might lose the crop to stray cattle again. But with a solar water pump, you will never go wrong as a farmer. My borehole has a lot of water, and I’m not even worried if there are delays in the onset of the rainy season,” Chadambuka said.

Chadambuka is one of the many farmers who benefited from Zimbabwe's land reform program. Through the program, the Zimbabwe government seized land owned by White farmers and distributed it to Black Indigenous farmers following the country's independence in 1980.

“You don’t need a lot of money to set up a solar water pumping system; you just need a few solar panels, a submersible water pump and few other accessories,” he added.

Across Zimbabwe, business is booming for traders selling photovoltaic water pumping systems; from small pumps designed for wells that are 20 meters deep to pumps for wells more than 80 meters deep. This solar water pumping equipment—mostly made in China and in some cases not durable—is instead affordable.

A recent study published in Nature revealed that pumping systems powered by photovoltaic energy are a promising solution to improve water access in many off-grid areas without significantly increasing greenhouse gas emissions.

“They are already economically competitive in many contexts; technological advances have improved their longevity, and local case studies have shown promising results,” the study reports.

[caption id="attachment_429" align="alignnone" width="675"] Water tanks for small-scale irrigation in Hurungwe area, Zimbabwe. Photo provided by Andrew Mambondiyani.[/caption] In a recent article , Professor Alan MacDonald, head of groundwater at the British Geological Survey and head of the International Association of Hydrogeologists (IAH), wrote in The Guardian newspaper that “across the African continent, the volume of water stored underground is estimated to be 20 times the amount held in lakes and reservoirs.”

Professor MacDonald noted that the opportunity that groundwater presents for increasing access to water was widely recognized, with more than half of the global population already believed to be relying on it for drinking water.

“When you add the ability of solar energy to power the necessary infrastructure and the fact that groundwater supplies are much more resilient than surface water during drought, the potential for harnessing this water source to provide a clean and regular supply to communities in chronic need comes into focus,” Professor MacDonald added.

However, on the other side, some experts have warned about the negative impacts of over-abstraction of groundwater in Zimbabwe. In a previous conversation with David Chikodzi, an expert on groundwater and Professor at Great Zimbabwe University in Zimbabwe, he told The Energy Pioneer that there was a strong link between groundwater and surface water resources.

“What is groundwater to a user in the upper catchment emerges as surface water in rivers or springs for someone who is in the lower catchment. Unregulated borehole drilling combined with climate change, overextraction called groundwater mining, does lead to a decline of groundwater without a doubt," Professor Chikodzi reported.

He added that the groundwater overexploitation was enhanced by the increases in storage capacities and the use of motorized pumps to exploit this resource.

"There is therefore a need for that coordinated approach to the management and exploitation of both surface and groundwater. It's not surprising that unregulated groundwater extraction is already impacting dry season river flow and depth to groundwater level,” said Professor Chikodzi.

He emphasized the need for consultations with citizens or water users to determine the best solution to this problem, rather than imposing technical or expert solutions on them.

“Instituting water demand measures appropriate to each area combined with environmental education will be the best,” Prof Chikodzi added.

He emphasized the need to allocate more resources to groundwater hydrology, the science that underpins groundwater policies. Without sufficient scientific knowledge of this resource, responses would always be inadequate.

The Zimbabwe government has clear laws on countering overabstraction of water. Before drilling a borehole, farmers need to apply for permission from any of Zimbabwe’s seven water catchment councils. These water catchments include Gwayi, Sanyati, Manyame, Mazowe, Save, Runde, and Mzingwane

The application form to drill a borehole in Zimbabwe is accompanied by proof of residence and a siting report that assesses the water table, geological nature, and suitability of the location. The catchment councils conduct frequent awareness campaigns in different communities in Zimbabwe with various stakeholders to educate them about water conservation, pollution prevention, and legal requirements.