Why Solar Powered Irrigation Systems

The Solar Powered Irrigation System is specifically designed for flood and furrow irrigation.
Over 395 smallholder farmers have benefited from the solar-powered system.
The system provides stability to households and income opportunities for locals.
Systems can be acquired through a loan, paid back over 2 years.
More districts in Malawi may soon have access to the Solar Powered Irrigation System.

Key Features

The Solar Powered Irrigation System simply consists of solar panels, a solar pump, sanction pipe, delivery pipe, and a solar pump house. This irrigation system is specifically designed for flood and furrow irrigation which is ideal for rice and maize cultivation respectively. The solar pump house is mainly incorporated in the system to serve the following purposes: provide shelter to the guard, provide storage space for irrigation equipment, and to hold solar panels on the roof.

Social Impact

SEE improves access to Solar Powered Irrigation Systems by providing solar pump irrigation systems to groups of smallholder farmers on a loan basis that is paid within a period of 2 years. Loan payments are made after harvests because farming is the only source of income for these small scale farmers. After the loan recovery period, farmers assume complete ownership of the system. SEE has sold 64 small scale solar powered irrigation systems supporting over 395 smallholder farmers in the Karonga district of Malawi. These farmers are food secure and resilient to climate change related effects since they practice solar powered irrigation agriculture. Children and women are living a healthy life since households obtain food self-sufficiency and increased incomes through solar pump irrigation systems promoted by SEE.

Future Plans

The growth plan is to expand the business to other districts across Malawi and ensure increased access of solar pump irrigation systems while mitigating climate change related effects on society. In this case, various products will be introduced on the market to ensure the needs of a variety of customers are met in order to further increase the customer base. SEE would also like to add value by becoming the biggest off-taker of rice produced by these smallholder farmers in order to ensure that farmers are not exploited by vendors.

Main Target Group

Smallholder farmers, commercial farmers, Non-Governmental Organizations (NGOs).

Main User

Smallholder farmers

Motor Pump

The pump has a motor running on electricity generated by the solar panel. Depending on the type of motor (AC or DC), the voltage of the solar pump motor can be AC or DC. DC motors are primarily used for small to medium applications, such as garden fountains, landscaping, drinking water for livestock, or small irrigation projects. Most DC pumps run at 24 volts rather than 12 volts.

However, smaller systems for 12 volts do exist for light-duty applications, while systems running on 48 volts also exist for heavier applications. The power of a motor is specified in either watts or horsepower (HP).

Pump Controller

There are two types of pump controllers: inverter and variable frequency drive (VFD). If an AC solar pump is used, an inverter becomes necessary to change the DC from the solar panels into AC. The supported power range of a typical inverter extends from 0.15kW to 55kW, with the higher power inverter being used for larger irrigation systems.

The solar panel and inverter must be sized accordingly to accommodate the inrush characteristic of an AC motor. Since the AC pump requires high power at the start, the inverter should be able to handle this extra start-up load. Sometimes a VFD controller is used to ensure that the pump motor gets proper voltage and current. Some typical specifications for various AC pumps and pump controllers are listed in Table I.