Transmission & Distribution (T&D) involves taking the electrical energy from the power stations and transmitting it throughout the island, then distributing to consumers. In a nutshell the T&D Department is responsible for keeping all DOMLEC’s customers lights providing that there is sufficient generation. In the event where there is a shortage of generation the department is also responsible for coordinating outages throughout the island prioritizing different areas of the network in terms of need and providing power to the areas where it is most needed. In order to keep the power on, maintenance work is done at any time of day or night. Managers, Supervisors and linemen are also required to be available at odd hours. New lines are constructed when it is necessary to optimise the power delivered to extant customers or when requested by a potential customer.
Customers would like to have power around the clock, the department’s long term goal is to improve maintenance to the point where unplanned and planned T&D network related outages is reduced to single digit figures.
Dominica is a small country however due to the island’s physical characteristics it has a very large T&D network which increases the difficulty of maintenance. The first attempt at improve operational efficiency was to re-design the approach to vegetation management, the results have been so fruitful that the number of outages has reduced as much as 62% in certain areas on the island these results have only solidify the need to continue that vegetation management method and further improve on deficient areas. The difference between the two methods is that the previous resulted in higher cost per mile of line cleared while the new method result in a lower cost per mile of line cleared thereby keeping the lines clearer for a longer period of time for the same cost.
Another challenge faced is the maintenance of the network hardware (Poles, cross arms, lines, insulators etc.). If not properly maintained, the hardware, like vegetation, will result in countless unplanned outages. The first step was to again re-design the maintenance method which was fragmented before but is all now with the maintenance section, this resulted in better coordination of the maintenance activities and a significant increase in the volume of repairs of defective structures and lines. Reliability of supply is the main focus one other action taken to improve supply reliability is through the use of joint compound which will protect connections on the network from the defective elements of the environment. Other tools and equipment will be investigated to make additional increases in our reliability and reduce maintenance time and costs.