Boreholes and pumping

1803 Land without access to water has very limited use. In many cases this can be solved by the use of a borehole. In remote locations a wind turbine can provide a very convenient power source for the bore hole pump making water extraction fully automatic. A water storage tank is usually used. There are two approaches which can be adopted

. Firstly is to couple a wind turbine directly to a DC pump without battery storage as described here. The pump is driven when the wind speed is high enough and water is stored in a tank above ground making it available on demand. It is often advisable to supplement the wind turbine power with that of photovoltaic panels to cope with periods of low wind speed e.g. dry hot spells associated with high pressure in summer. This is the approach often adopted for very small supply requirements.

The alternative approach is to use a standard AC bore hole pump pump driven by an inverter supplied from storage batteries. The batteries are then charged by a suitable wind turbine or preferably cobination of wind turbine and photovoltaic panels. A typical system is described here. While this is a more complex solution it does have a number of advantages particularly where the water is required for an agricultural building or field shelter.

hut The AC pump are not as electrically efficient as the DC types but they are simpler and very well tested technology offering excellent life. In the event of a system failure the pumps can be run by any suitable portable AC generator. The electrical system will provide 230Vac power for lighting and hand tools.

Size of wind turbine

In this case the electrical output of the wind turbine is stored in a battery bank to provide energy and power on demand. The size of the wind generator required now depends directly on the average electrical energy consumed. The size of the battery bank will depend in part on the peak power required and but also the size of the water storage tank. the reason for this is that it is necessary to be able to make water available even if there is no wind. it is advisable to have sufficient storage to deal wth several days ( even longer depending on the use). This storage can be in the form of water in a tank on the surface or battery electrical power to pump water when needed. A detailed examination of the environment and the requirements are needed to ensure an optimum solution. The Marlec FM910-3 and FM1803-2 are suitable wind turbines for this application.

Essential requirements

a survey - average wind speed and presence of obstructions such as trees etc.
planning permission from your local council
a survey for bore hole