Design and Construct a Solar Powered Water Pumping System For Irrigation

1.1 Background Currently, there is high demand for food in the country due to the rise in the population. Farmers are facing a lot of challenges to provide enough food for the growing population because of unpredictable rain seasons. Most of them have now turned to irrigation as the only way to overcome the problem. Many people in rural areas collect the water in containers (buckets, basins, cans etc) and carry it on heads, use hands, or bicycles, carriages, etc to places where it is required for irrigation. Farmers in most of the rural areas have decided to make terraces so as to lead water right from the water source to the point near the garden where it can be collected, but the effort has not yet succeeded since this method is applicable only to farmers near the river and ponds (Nabende, 2003). Some of the people in rural areas have developed their own water system that involve the use of pumps to raise water from a lower source e.g. under ground water tank, open wells or harvested rain water to the water storage tanks in the gardens ready for irrigation (Nabende, 2003). Different power sources are used for driving these pumps and these include wind, manual operation by hands or pedaling, grid power, generators, engines, and solar energy. Most of the people in the rural areas had turned to electricity as the major source of power for driving the pump but due to the problem of electricity shortage that is being faced by country, electricity as the source of power has turned out to be quite unreliable and expensive means of driving the pumps or any other machine. This has necessitated development of the solar system which requires low operation cost compared to electrical system to drive the motors or engines that finally turns the electrical energy to mechanical energy, so as to pump the water to the required destination. This is a cost effective method because the pump utilizes the energy from the natural light, and pumping of the water to the garden can be fulfilled at any time. In most cases the solar can also be used to charge the batteries which can be used to run the pump during night hours (Kaguamba, 2008). Solar panel can be found in market at various sizes and power ratings; they can be applied differently according to the head at which the water is to be pumped to.

1.2 Problem statement There are many systems of pumping water that are currently used including engine driven pump, grid powered pump, manual powered pump and generator driven pump. However, there are inconveniences associated with these systems as follows o Due to the steady increase in the price of fuel for the past few years, most of these systems have become expensive leading to an increase in the price of water for domestic consumption and irrigation.

o Most of these systems require high maintenance since they have many moving parts.

o There is low grid power coverage in the country, therefore grid powered pump can not be used in most of the parts in the country.

To overcome the inconveniences, there is a need to design and construct a solar powered water pumping system that can be used for irrigation.

1.3 Objectives Main objectives o The main objective of this project is to design and construct a reliable and cost effective solar powered pump that can be used by the farmers for irrigation. Specific objectives o To design a solar powered system that can provide enough power for pumping water to the head of 5m. o To construct and test the prototype so as to determine its efficiency.

1.4 Justification Different pumping systems have been adopted by the farmers, mostly those who carry out farming on small scale. Some of the systems include the use of generators driven pumps and manual pumps. However, they are many problems that are encountered during the use of these systems; some of these problems have a great impact to the environment. The design of solar pumping system will overcome some of these problems. There are many different benefits associated with the use of solar powered water pumping system including: o Solar powered water pumping system is quite environmentally friendly i.e. there are no emissions that are discharged to the environment during the pumping process. o Considering all costs such as installation, fuel, maintenance and waste, solar water pumping is often less expensive than generators, windmills, and running electrical lines. o Solar systems can be more easily moved to meet seasonal or variable location needs unlike wind mill and generators which are stationary. o Properly installed solar electric systems are safe. Risk of electric shock is small because of low system voltage. Therefore the design of solar powered water pumping system will thus contribute to meet or solve the requirements of the farmers.

1.5 Scope of the project This project is intended to design a pump that uses solar energy to pump water. Here emphasis is put on the electrical energy in relation to the efficiency of the pump. This project targets mainly the rural population where electricity is not available or it is unreliable. 1.6 Output of the project o The pump should be easy to maintain i.e. easy to be dismantled and assembled.

o It should be simple and affordable compared to the electrical pump. o Should be small enough for limited space operation o Should not consume a lot of power i.e. power losses should be minimal.

o The pump should pump water at the head of at least 5m for irrigation and domestic use.