solar-powered pump is a pump running on electricity generated by photovoltaic panels or the radiated thermal energy available from collected sunlight as opposed to grid electricity or diesel run water pumps.[1] The operation of solar powered pumps is more economical mainly due to the lower operation and maintenance costs and has less environmental impact than pumps powered by an internal combustion engine (ICE). Solar pumps are useful where grid electricity is unavailable and alternative sources (in particular wind) do not provide sufficient energy.

Solar water pumps can supply water to locations which are beyond the reach of power lines. Commonly, such places relie on human or animal power or on diesel engines for their water supply . Solar water pumps can replace the current pump systems and result in both socio-economic benefits as well as climate related benefits. The water supplied by the solar water pump can be used to irrigate crops, water livestock or provide potable drinking water.

A solar water pump system is essentially an electrical pump system in which the electricity is provided by one or several PhotoVoltaic (PV) panels. A typical solar powered pumping system consists of a solar panel array that powers an electric motor, which in turn powers a bore or surface pump. The water is often pumped from the ground or stream into a storage tank that provides a gravity feed, so energy storage is not needed for these systems.

A typical installation is illustrated in Figure 1

 

The major pump types are surface-mounted pumps and submersible (deep-well) pumps – as shallow-well water pumping requirements are different from those for deep-well water pumping. In latter situations of wells deep in the ground, it makes much more sense to put the water pump near to the well source in order to basically push up the water.

Climate top: 

When solar water pumps replace either diesel generated electricity or grid based electricity, there are certain climate related benefits. A diesel generator emits CO2 during operation and grid based electricity is usually generated with either coal, oil or natural gas which also emits considerable quantities of CO2. In contrast. a solar based water pump system does not result in greenhouse gas emissions. Extensive use of solar water pumps would therefore lead to substantial greenhouse gas emission reductions.

Financial requirements and costs top: 

Several aspects of a PV pump system are key in determining the system costs:

  1. a) size of the system. The high initial capital costs of the PV array is the major barrier to high penetration rates of the use of solar water pumps . The PV array is the most expensive part of the system. The size and capacity of the PV array considerably influences the up-front costs of the system. Therefore, it is important to use the smallest system size possible that still meets all the criteria of that particular location. Government or aid agency subsidies which cover the high initial capital costs are required in many locations to realize PV water pump systems. The high reliability of solar water pumps might offset its higher initial costs compared to diesel powered pump systems .
  2. b) insolation levels. This is directly related to the required size of the system. The intensity and number of hours of sunshine determine the capacity requirements and thus the PV array size requirements. The more sunshine, the smaller the system requirements.
  3. c) pumping head. The pumping head is the distance over which the water needs to be moved. The costs of water volume unit are proportional to the pumping head., While system size and insolation levels greatly influence the capital costs of a PV water pump the operational costs of the system are generally very low due to low labor and maintenance costs. In contrast, inexpensive diesel or gas generators have low initial capital costs but require constant maintenance and the parts have shorter lifetimes which increases operating costs.

This long-term economic advantage makes solar water pumping more cost-effective to conventional pumping systems, such as diesel powered pumps . .

The study by Odeh et al. found that PV water pumping systems are more cost-effective than diesel pumping systems for equivalent hydralic energy below 5750 m4 /day and 21.6 MJ/m2 day average insolation. In turn, diesel pumping becomes more economical for larger applications . This difference in costs over a long term is clearly illustrated in Table

PV systems are particularly useful in locations to which it is not practical to extend the grid. Even in locations where connection could be made to a grid, utilities have found it more viable to use PV pumps than to extend and maintain the electric grid.

Table 2. Comparison in financial requirements between five PV systems and five diesel pump systems of increasing size. Source: (Odeh, Yohanis & Norton, 2006)

System

Total Capital Costs (US$)

Total Operating Costs (US$/year)

Total costs over a 10-year period 

Total costs over a 20-year period

PV 1 (2800 Wp)

18 188 600 24 188 30 188

PV 2 (4500 Wp)

27 470 800 35 470 43 470

PV 3 (6300 Wp)

37 398 900 46 398 55 398

PV 4 (10 000 Wp)

56 800 1400 70 800 84 800

PV 5 (15 000 Wp)

82 000 1600 98 000 114 000

Diesel 1 (3.5 KVA)

3840 5642 60 260 116 680

Diesel 2 (4.5 KVA)

4720 5864 63 360 122 000

Diesel 3 (6.3 KVA)

6050 6029 66 340 126 630

Diesel 4 (10.0 KVA)

8350 6307 71 420 134 490

Diesel 5 (15.0 KVA)

10 320

6593 76 250 142 180

Applications of solar water pumps

According to each individual need, solar water pumps can be applied for a range of different purposes where pumping water is needed.

Main applications include:

  1. a) Crop and plant irrigation
    b) drinking and cooking water supply
    c) swimming pools
    d) industrial water processing
    e) fountains
    f) irrigation for Farming
    g) drinking Water for Livestock
    h) swimming pools

Off-Grid Solar Systems

Off-Grid Solar Systems

On-Grid Solar Systems

On-Grid Solar Systems