How vandalism affects electricity supply/distribution

In recent weeks Uganda Electricity Transmission Company Limited (UETCL) has been challenged upon fully delivering its core mandate (bulk electricity purchase from generators and bulk electricity selling to distribution companies or large industrial consumers), mainly due to rampant vandalism of the transmission and distribution assets.

Vandalism at all levels of the electricity supply/distribution chain is unwanted. Emphasis hither is to digress vandalism levels associated with electricity assets and how they affect the electricity supply/distribution chain in the country. Vandalism can manifest in up to four levels; at the consumer end, distribution level, transmission, and generation levels. However, the severity of its impact(s) differs according to the levels mentioned above, if they occur independently, but can be extremely acute if they occur in parallel.

Consumer end vandalism: Electricity consumers broadly are domestic and industrial. The main form of vandalism at this level is power bypass (power theft), but our focus today is limited to assets vandalism. Vandals target items like conductors, distribution boards/panels, reactive power compensating devices (such as capacitor banks and reactors), transformers, and wooden poles in some cases. Illegal removal of these items/equipment from the network, manifests several power faults (from single phase to three phase).

The impact here is mainly associated with a small area coverage of power distribution but can escalate to wider areas if the area transformer goes out completely, and if power network protection devices fail to isolate these faults, they can spread up to the distribution substations, causing larger area severe power forced outage(s).

 Distribution level: Vandalism here is identical to the consumer level one. Key items/equipment targeted are distribution conductors (mainly overhead lines), stay wires (supporting electric poles), transformers (mainly for, transformer oil, copper, and in some cases resell the entire transformer to black market buyers). Similarly, losing any of these items/equipment, causes an imbalance in the electricity distribution leading to several power faults.

At this level, the affected area is wider compared to the previous level, and if the power protection devices fail to timely isolate these faults quick enough, we can have cascaded outages, taking out several villages or even escalating to taking out regions.

Transmission level: Vandals here mainly target transmission towers/pylons. They cut off the cross members (struts), designed to provide mechanical support and strength to transmission towers. Given the meshed nature of transmission towers, its relatively effortless for the vandals to climb, slice off the cross members, leaving out only the four pillars of the tower, and a few cross members which are too close to the live parts of the tower. Essentially this weakens the transmission towers, and due to the vibrations of the electricity carrying conductors, the towers lack enough mechanical strength to withstand these vibrations and wind speeds, hence falling to the ground. This again causes faults (phase to phase or phase to phase to earth) which trips the circuit breakers on lines thus losing transmission supply.

Since transmission supplies bigger loads via distribution stations, this causes regional forced outages possibly extending to national blackouts if system synchronism is lost, and if restoration is not smooth and fast, blackouts or forced outages take longer durations.

Generation level: Uganda Electricity Generation Company Limited (UEGCL) and Independent Power Producers (IPPs) hardly report, or mention issues associated with vandalism. Potentially because generating facilities are usually located in a central place, that can swiftly be monitored and secured, as compared to transmission and distribution where lines cover longer distances making it challenging to secure and patrol all to minimise vandalism.

Mr Stuart Kasozi is an expert, power systems integrity   & Chevening Scholar 2019/2020