Nabard's Guidelines for Solar Electric Fencing

Online, January 12, 2010 (Newswire.com) - Introductions for Solar Electric Fencing of Agricultural Farms:

Wildlife damage problems are as old as man. Crop raiding by herbivores like deer, rhinos, elephants, boars, domestic animals etc. is a major problems for farmers. From time immemorial farm fencing has been evolved and used to protect the hard earned crops of farmers in their fields Many techniques like digging trenches, ditches, hedges, stone piles, earth piles, boundary walls, barbed wire and chain link fences are used to protect the farm. However, a few are sometimes very costly and many do not serve the purpose of protecting the hard earned crops.

In the process of development, power fencing (electric fencing) has been found as one of the best methods that are being used all over the world. It is one of the cheapest and most effective methods of fencing. However, due to lack of proper information, many farmers in India are not using power fence to protect their crops or sometimes resorting to unscientific and illegal electric fencing resulting in death of animals. Use of incorrect power fencing and the resultant death of animals are appearing in the news and individuals/corporations are being penalised to pay damages for the act of negligence. Therefore, there is a need to disseminate the information about a scientific power fencing system.

WORKING PRINCIPLES OF ELECTRIC POWER FENCING SYSTEM:

Electric fencing is emerging as one of the best methods for protection of crops and property from domestic and wild animal damages. The fence comprises of several strands of galvanized iron (Gl) wires drawn along the perimeter. A high voltage electrical pulse is transmitted through the wires. Any animal/human being touching the wires gets a sharp, short, painful but safe shock. The animals hesitate to come in contact with the fence again. The fencing thus becomes a psychological but active barrier and the animal/human being will not generally attempt to negotiate the fence again.

The electrical impulse is generated by an energizer. The energizer produces high voltage impulses of approximately 8 kv once in every 0.9 to 1.2 seconds. The impulse lasts for approximately 300 millionths of a second to 0.1 second and has a current of up to 10 mA. The current supply is generally available from 12 V battery charged either by solar power or from a general electric supply system.

ADVANTAGES OF THE ELECTRIC POWER FENCING OVER THE CONVENTIONAL METHODS
1) Electric power fencing is easy to install and installation cost is low.
2) It has a low maintenance cost.
3) The system has a very long life.
4) It can be designed to control the target species.
5) It is portable and reliable.
6) The system has recognised international standard.
7) The system is eco-friendly.
8) It has low maintenance cost.
9) The system is safe and effective. Control is achieved by psychological means.

DESIGN AND INSTALLATION OF SOLAR POWERED ELECTRIC FENCING:
DESIGN:

The key to fence effectiveness is to maintain its ability to shock throughout the fence. It depends on

a. design and construction of the fence in relation to the species in question,
b. selection of right energizer,
c. soil conditions,
d. length of the fence,
e. proper selection of wire, insulators and other fence accessories, etc.

Voltage that determines the shock ability can be maintained throughout by minimising resistance all along the fence. It is achieved by:

a) Use of quality components Which offer little resistance for power flow as in wires or prevent leakages as in insulators.

b) Adequate earthing to ensure movement of electrons through the ground, and

c) Suitable fence layout.

The cable connecting the energizer to the fence wires, fence wire and connections all offer resistance which needs to be minimised, A thinner wire offers more resistance Ideally, the
voltage between live wire and earth should not exceed 200 volts. It should be as close to zero as possible Floor earthing indicates that adequate flow of electrons is not taking place through the earth to all parts of the fence.

Resistance can also be reduced through optimal layout. Location of the energizer in the middle of the perimeter can be more effective than the traditional housing of the energizer along the fence line
Various methods of construction are used depending on the terrain and the animals to be enclosed. One wire is used for horses, mules and cattle Two wires are recommended for swine. Energized gate wires require an insulated handle for hooking and unhooking the wire.

The controller provides the shock sensation for keeping the livestock within/ beyond the enclosure.

Survey of land/ area to be fenced:

Proper data collection is an essential feature of a safe and successful power fence. Data on following aspects are collected during the site survey:

a) Where the system is to be used and the type of land it is to be used on
b) The type of stock one is carrying or wish to fence off.
c) The size of the area one wishes to fence.
d) Whether the system is to be permanent or movable.
e) The type of wire you wish to carry the current.
f) The conductivity of the ground on which the system will stand.
g) The type of energizer that will be,st meet your needs.
h) The type of insulators to be used.
i) The most effective earthing system.
j) Types and locations of gateways.
k) Efficient insulation of wires from ground