Developing Solar Water Pumping Technologies
I am enquiring about who I might contact with reference to research on solar-powered water pumps.
I am a retired Economics lecturer (Queen’s University Belfast; formerly, Oxford University Agricultural Economics Institute. Book, 1982 on Economics of African Agriculture, and one on Sierra Leone agriculture.)
Some time ago, I thought of a device for solar-powered pumping, and though I consulted engineers and others, I never had the technical wherewithal to pursue it. Essentially the idea is to harness solar energy to do work, but mechanically, rather than through photovoltaic cells, etc.
Could you supply me with names of people who would be in a position to consider its merits, and perhaps take it forward.
From: Neil Noble Sent: 24 August 2015 12:20 To: 'email@example.com' Subject: FW: Solar powered pumps enquiry
This subject was popular many years go in the 1970s but seemed to drop off, possibly because of improvements in technical aspects of photovoltaic systems although, solar PV water pumps have taken a long time to become viable in development environment in Africa rather than larger commercial applications.
It has only been over the last few years that the cost of PV systems has reduced to an extent that it is now viable to introduce these systems, although there will still be an issue on the supply chain and maintenance. Practical Action is currently installing solar PV water pumping systems in a number of African locations along with developing the supply side of things.
For non PV designs of water pumping I think there were a few different options looked into. External heat engines, such as Stirling Engines, steam engines would be able to use solar thermal energy. The extract from the old VITA document outlines the situation a little better.
The history of thermodynamic solar water pumping technology goes back nearly four hundred years, when Solomon de Caux in France raised water for a fountain by the expansion of solar-heated air. By the beginning of this century, many of the currently competing design concepts had already been explored, and several promising attempts at commercialization were under way when activity subsided due to the advent of the internal combustion engine and cheap commercial fuels. Much of this development had been aimed at relatively large-scale applications. It was not until the resurgence of interest in solar energy caused by the 1973-1974 oil embargo that greater attention began to be directed at small-scale rural applications in developing countries.
Of particular interest to the serious reader in this field is the definitive and comprehensive work done in conjunction with the United Nations Development Programme/World Bank Small-Scale Solar-powered Irrigation Pumping Systems Project by Sir William Halcrow & Partners and the Intermediate Technology Development Group, Ltd. The most important reference for the prospective solar pump user is Handbook on Solar Water Pumping.
In contrast, the development of photovoltaic water pumps has heavily emphasized small-scale rural applications since the 1960s. While both of these technical approaches continue to mature, neither can yet be judged inherently superior. Most of the recent efforts, however, have concentrated on photovoltaic systems and a majority of solar pump field operating experience has been with photovoltaic installations.
All thermodynamic systems use a solar collector to convert solar radiation to heat and a heat engine to convert the heat to mechanical power for pumping. In heat engines a fluid or gas absorbs heat at a higher temperature, which causes it to expand; it then contracts upon removal of the heat at a lower temperature. This expansion and contraction is harnessed to move a reciprocating piston in a cylinder, or it can expand against a turbine wheel.
The necessary temperature ... (more)
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