Description

Chikwawa is one of the districts in southern Malawi which experience extreme climate condition, drought and floods. Lying in the lowlands and flood prone area, it has been ranked one of the worst disaster affected district.

In Msiyamphanje village there are 530 households with an average land holding size of 1.2ha. The community suffer from shortage of food, the rainfed agriculture does not provide sufficient food and income to last the whole year. The village has a high yield alluvial aquifer. Shallow wells were drilled to supply water to household and backyard irrigation.

The main challenge of accessing water in this village is the lifting energy from the wells and natural reservoir which are located in the village.

To address the problem of reliable domestic water, the project focused on the excavation of 3 shallow well which were lined and installed with small solar pumps having one solar panel and used for domestic usage.

There is need to address the problem of irrigation water by utilizing the existing wells and water reservoir through pumping with solar energy.

Technical description

Solar kits often described as Solar Water Well Pump Kits rely on solar radiation to pump water from a well and in most cases shallow wells, using a submersible solar pump that pumps water into a tank (maximum 4000Liters) raised at 1m. From the tank, the water is discharged using a low pressure system that can be connected to a drip irrigation system or a tap for domestic use. The system utilises a submersible pump which is placed inside a well. The well can be 20-40 m deep. A combination of solar pumping and drip irrigation is the most efficient use of water with no carbon emission and 80% application efficiency. Once the system is in place, no energy is required to pump water for irrigating the gardens. The system is operated by switching on the pump to fill the tank and with a control valve at the tank outlet which is used to discharge water to a drip system.

The main characteristics of the solar kits installed in Chikhwawa, Malawi, are:

Type of Pump: DC 24V Submersible
Power Range: 120W
Number of solar panels: 1 unit 250Wp, Polycrystalline
Controller/control panel: Without, direct coupling
Flow rate per day: Maximum 4m3 per day
Total head : Maximum 40m
Cost (pump, solar panel, well , drip set and installation): $2,700

Small solar kit can pump 4m3 of water per day, using 3m3/day as an average discharge. This amount can irrigate a vegetable field of 3hactares with an average water use of 8mm per day for vegetables in Chikwawa.

The solar kits can also be used for domestic water supply and with some water treatment, it can offer a simple and efficient water use for small communities.

Objectives and beneficiaries

Objective: Access to water for both domestic and irrigation. Irrigation can be done as a back yard garden or on a small field of 3hactares for income, nutrition and food security in Malawi.

The main advantage of the system:

- Use solar as a green energy source for water pump.It is clean, renewable, and emits no greenhouse gases or pollutants when in operational.
- Only one solar panel used, simple and low cost ($2,700 as total installation) under proper management, this can generate $8,793 as profit per year.
- Water is drawn from a well which can be excavated manually or drilled mechanically.
- The pump is small and cheap making it affordable for small community projects.
- The solar panel is very efficient in capturing solar radiation even in cloudy weather.

Strong points of the practice

Drip Irrigation system is the water saving technology in the context of growing population and climate variability.
Solar pumps generating power from a single panel are a cheap & green sources of energy.
Shallow wells offers cheap and easily accessible water points for communities.
A combination of the three makes the best, and cost effective practice for small scale agriculture water management.

Expected results and benefits for climate change adaptation and mitigation

Small solar kits connected to Drip Irrigation can be installed and benefit communities in many area in Malawi for irrigation. In Chikwawa, all shallow wells around the area can be drilled manually to a depth of 5m and yield water for irrigation.
One solar kit installed in Chikwawa can benefit 15 household. 3ha field planted with vegetables can provide a profit of $2,931. This can contribute to improved income in the households.
$10,000 can buy and install 4 small solar kits and benefit 45 households (225 inhabitants).

Replicability potential of the practice

- Anywhere in Malawi where a shallow well can be drilled (manual or mechanically) and exposed to solar radiation within a radius of 50m.
- All districts in Malawi along the lakeshore with high yield alluvial aquifers.






[Editor's Note: All information published as submitted by the author(s). Minor edits may have been made to increase readability and understanding.]