Electricity Business Challenges in Nigeria 3

What do you know about the current transmission and distribution system?

Which is more preferable in power systems, underground cable or overhead line?

The distribution and transmission network in Nigeria is mostly (90%) based on over head lines. The 330kV, 132kV, 33kV, 11kV, 415V lines are mostly based on overhead lines. In the distribution network, these conductors are usually placed at least 7 metres above the ground, suspended using concrete or wooden posts, far from human reach. Furthermore, these conductors are usually not insulated; however, they are isolated from the poles using porcelain insulators. In the transmission network, these conductors are placed at a higher height than that of distribution network due to the higher voltage in the network, and they are suspended using metallic structure which is composed of steel trusses. In addition, the conductors are suspended using glass insulators.

Advantages of Overhead Line

·         Lower capital costs.

·         Easy accessibility to the operators.

·         Quick time for repairs.

·         Easy upgrade.

Disadvantages

      ·         Easy accessibility to illegal connection touts and consumers.

       ·         Easy accessibility to vandals.

       ·         Highly susceptible to bad weather conditions such as wind, rain, snow, etc.

Given the current distribution system in Nigeria, where consumers engage in illegal connections, it can be said that overhead distribution lines can never work in Nigeria. The peoples’ orientation on energy theft needs to be dealt with appropriately. There is always a sudden trip-off of power supply whenever there is thunderstorm, rain or wind in Nigeria. Rain decreases the insulation provided by the surrounding and calculated separation of the conductors, this causes leakage currents which instantly triggers the safety measures and the control point. Thunderstorms, the electric discharge from a lightning bolt can trigger safety control systems as well. High wind speeds can wreck havoc on building, and overhead line structure. Furthermore, due to the problem of incessant vandalism on, it will be better to look into better way of securing the system as well.

Underground cables, most developed nations have phased out overhead lines; New York has no overhead line since 1890’s, Singapore has 100% underground network, The Netherlands has 100% distribution network, etc. So why can Nigeria embark upon underground cables distribution and transmission network. There are only few places with underground cables; example, parts of Sokoto State Polytechnic, Sokoto.

Advantages of Underground Cable

       ·         Not susceptible to bad weather conditions.

       ·         Unexposed to vandals.

        ·         Unexposed to illegal connection touts.

        ·         Low maintenance costs – if well panned and managed.

Disadvantages

                ·         High lifetime costs – needs to be replaced at expiry date to guarantee safety.

       ·         Upgrade needs an overhaul the installation.

       ·         Fault location is instantaneous but repair can take some while to be completed.

The beauty of underground cable network is that it prevents illegal connection, energy companies will definitely benefit from this because it will bring energy theft to a halt; however, this will involve a lot planning, dedication and investment. Once an underground cable has been buried and commissioned, it can last for up to 40 years and if its capacity is not exceeded, then it serve the community throughout its lifetime. No individual or group can successfully vandalise an underground cable, and bad weather conditions have no effect on it.

More coming soon....