How solar-powered water pumps are boosting productivity and resilience for Cambodia’s farmers

In Cambodia, the agriculture sector employs up to 37 percent of the labour force and contributes to 21 percent of the country’s gross domestic product (GDP). Yet this key sector is also the most vulnerable to the impacts of climate change.

Known as “the rice basket of Cambodia”, the Tonle Sap Lake Basin experiences repeated cycles of severe droughts and floods. The Fourth State of Environment Report and Cambodia Forest Cover 2018 (released in 2021) reveals that droughts affected more than 1 million hectares of rice fields during the rainy season from 2015–2019, resulting in an estimated loss of US$100 million. Faced with the new realities of drought intensity and increasing water shortages, vulnerable smallholder farmers are experiencing both lower agricultural productivity and reduced paddy cultivation – from multiple seasons to just one.

Enhancing crop and livelihood resilience

In response to these growing challenges, the United Nations Development Programme (UNDP) with financial support from the Ministry of Agriculture, Food and Rural Affairs (MAFRA) of the Republic of Korea has been working with the NGO People in Need (PIN) to deploy and test large-scale solar water pump systems.

The solar water pumps use sunlight to generate electricity and power a motor that draws water from either under the ground or from ponds, lakes, canals or rivers for household use and irrigation. These systems have an engine capacity of over 20 horsepower (hp) and are being implemented in three drought-prone communities in the Tonle Sap floodplain of Battambang and Kampong Thom provinces.

The pumps are providing a reliable water supply for irrigating 80 to 250-hectare fields, especially during the dry season, and have the potential to reduce water waste. They are also creating new opportunities for farmers, especially smallholder farmers, to increase the resilience of their crops. The ability to secure irrigation water during the dry season is allowing farmers to plant rice for a second season, or to plant other vegetables and crops such as watermelon and chili pepper. Further, the constant availability of water in the canals is creating a conducive habitat for fish and water birds, which enables farmers to engage in subsistence fishing and to access an additional source of protein.

Experiences from Prek Norin

Farmers in one of the targeted communities of Battambang province, Prek Norin, were initially reluctant to use the solar-powered water pump installed in their area. However, they gained peace of mind after witnessing the pump in action. “It runs from morning until sunset quietly and fills water in the secondary canal quickly,” one of the farmers noted. “There is no loud engine noise and no black smoke.”

Chorn Channa, a member of the Prek Norin community, is excited to have the system in her village. She shares that having a secured water supply is eliminating many challenges for farmers, mainly by removing the need to pump water. She simply needs to open a gate to flood her field without the need to use a secondary pump.

Having canal water also means that farmers like Chorn Channa no longer need to compete for water, which reduces the potential for conflict in the community. This decrease in competition benefits smallholder and poorer farmers in particular, who were often left without water for their fields.

These communities see solar water pumping as a cost-effective solution compared to diesel-powered pumping, which is considered a luxury that can only be afforded by farmers with greater means. In the past, vulnerable and smallholder farmers could not afford to buy fuel for pumping water, which resulted in lower rice yields or losses. Chorn Channa explained that the diesel pumps often failed and had high maintenance costs.

A way forward for solar water pumping

Large-scale solar water pumping drives economies of scale that reduce operation costs significantly and offer productive uses of solar energy besides pumping. These other uses reduce the overall costs for smallholder farmers. For example, the combined power from all solar photovoltaic (PV) panels used for one of the pumps could electrify a small community of 50 households. Plans are already in motion in the solar pumping communities, with Prek Norin hoping to use the energy from these systems for a chicken feed grinder and Orkunthor community planning to power a crop dryer to reduce post-harvest losses.

Smallholder farmers are now seeing an opportunity to improve their productivity and reduce agricultural losses. The large-scale solar systems are opening the door for smallholder farmers to access a secured water supply for second or third season crops. Moreover, the solar-powered water pumps are helping to reduce environmental impacts and greenhouse gas emissions by avoiding the use of diesel pumps for off-grid electricity. This is resulting in reduced energy costs for irrigation and is increasing the resilience of crops to climate change impacts such as drought.

De-risking private sector investments in solar water pumping systems is a key area for development partners to prioritize. Financing these systems will support both our ability to combat climate change and to mitigate its impacts on vulnerable farmers by safeguarding their livelihoods.

The project "Promoting the Use of Solar Technologies for Agricultural and Rural Development in Cambodia" is supported by the Ministry of Agriculture, Food, and Rural Affairs (MAFRA) of the Republic of Korea and the United Nations Development Programme (UNDP), and is implemented by People in Need Cambodia.