by MyEngineers,
The Nigerian Electricity Supply Industry is going through phases of multiple challenges from regulation, enforcement, lack of proper coordination, financial challenges, inter-agency rivalry, political interference, labour issues, frequent system collapse, energy theft, customers dissatisfaction, customers extortion, etc.
The customers (Nigerians) are interested majorly in the duration and quality of affordable power delivered to them at a particular period, they care less about the technicalities behind the scenes that brings that electricity supply to their doorstep. Therefore, it is important that the regulator and technical enforcer must see the plight of Nigerians from a holistic point of view rather than inter-agency rivalry and self-aggrandizement.
The Nigerian Electricity Supply Industry needs to be reviewed technically and periodically by analyzing the best approach to distribution of power supply at distribution level, what voltage level will be best considering the economic and technical implication alongside the growing demands of electricity supply as the country population increases. Analyzing the 33kV ban on the indiscriminate connection of points loads on 33kV lines and increase use of 33kV as secondary MV distribution is important, and to note what the merit or demerit can be, as we are driving towards an alarming future crisis both economically and technically.
Today in Nigeria, the distribution companies find it easy, cheaper, and convenient to connect point loads on their 33kV network without looking at the overall effect on their revenue, network expansion, and reliability of the network.
A 33kV network using 150mm2 ASCR cannot radiate more than 51km before you begin to experience voltage drop. Unfortunately, most of the 33kV networks in Nigeria exceeds the maximum 51km line length but are in the region of 70 – 120km which have led to the increase in unreliable, unstable, and unsafe 33kV network.
A 33kV overhead line using a 150mm2 ASCR conductor cannot deliver more than 24MW of power and at the maximum power of 24MW it cannot radiate more than 30km before it begins to experience significant voltage drop. 33kV networks are expected to be a sub-transmission line used to deliver power to injection substation for easy distribution and increased access to customers/consumers. Connecting point loads on the 33kV network increases its susceptibility to faults, instability, and unreliability.
For instance, a 2 x 15MVA 33/11kV substation is expected to radiate out an average of 8 numbers 11kV feeders at a maximum load of 3MW and cover an average distance of 18km each. Therefore, having an injection substation increases the access of the distribution companies’ network to their customers/consumers. Note that major districts in Abuja metropolis that are on the tariff band A non-MD are all on 11kV network.
A combined network of 33kV and 11kV network is expected to deliver 24MW to customers/consumers in a radial network with an average distance coverage of 195km with a high reliability index while distribution on only 33kV network might be reliable but the reach/access to customers/consumers are relatively low. This has not considered the length and coverage of the 400V distribution lines, if the reach to customers/consumers on 11kV lines are higher compared to 33kV lines, why do the discos prefer connecting point loads on 33kV lines.
Also, if 33kV lines is continuously used indiscriminately to connect point loads rather than the use 11kV lines, we should have it in mind that we need to increase the numbers of 132/33kV substations around the country to be able to meet the growing demands of electricity. How much is the cost of building a 132/33kV substation compared to building a 33/11kV substation? Why do TCN build 132/33kV substations without due consultation and consideration of the discos who are the custodian of the high and low energy demand customers/consumers?
What is the regulator and technical enforcer doing to close this gap? TCN sometimes operate with no economic and technical reasons for siting its substations in different part of the country. They can decide to build a 2x45MVA 132/33kV substation at Wukari, Taraba state or Ibillo, Edo state without considering the energy consumption of the area and the growth plan of the disco that covers that area. This is a big gap that bedevils the entire growth of the power sector.
This is a huge responsibility of the regulator to force TCN and Discos to have an expansion plan that is inclusive of both parties and a timeline for implementation. With the above, the power sector can have a define timeline which is specific and measurable in terms of energy that can be evacuated form the Gencos and where they are expected to be delivered. The number of 132/33kV and 33/11kV substations to be built will be determined, amount of energy to be evacuated, number of consumers/customers expected to have access to the power can all be determined? This will eliminate the backdoor encouragement the regulator gives the discos to connect point load indiscriminately on 33kV lines on the excuse of no 11kV lines? Who do the regulator expected to provide the 11kV line?
It is expected that the regulator should be looking at the overall effect technically and financially on the Nigerian Electricity supply industry and note that close to 90% of the transformers and other equipment purchased and installed are by customers or govt not the discos?
How is the regulator monitoring the CAPEX of the discos when transformers, poles, cables, and other ancillary equipment are purchased by the customers or govt? How many are the capital projects that the discos have embarked upon with respect to the CAPEX annually and why has the regulator not requested for a timeline from the discos on how do they intend to close the gap on the reticulation of 11kV line because the country population is growing daily and access to electricity increases daily?
To monitor the disco on the implementation of the CAPEX, why is the regulator not collaborating with the technical enforcer, it is a known fact that the technical enforcer has more present around the country than the regulator.
Furthermore, we need to ask ourselves do connection on 33kV sub-transmission network increases revenue to the Disco? This question cannot be answered directly but as you read through this article, you can form your opinion on disco’s revenue challenges.
A 33kV sub-transmission line that feeds point loads directly or have point loads on its line before an injection substation are subjected to different disturbances that have significant effects on the reliability, stability, and revenue collection.
Due to no adequate protection on the 33kV line, any fault on any of the branches will result in outage for a period, that time of outage reduces the energy consumption and revenue required to be generated on that 33kV line at that period. It is possible that within that period zero electricity was consumed on the 33kV line.
If the 33kV sub-transmission lines links an injection substation (33/11kV) without any point load on the line, the probability of the line experiencing a prolong outage compared to a 33kV line with point loads will be relatively very limited. Most faults will be limited to the 11kV feeders and not the 33kV feeder, therefore at most times during any fault the 33kV line will have power supply and revenue can still be collected on other radiating 11kV feeders unless there is a system collapse or a major fault.
However, I think the disco understands better reasons why they decide to radiate 33kV lines rather than 11kV lines that will increase their customer coverage and access. Note that most of the 33kV lines are not adequately protected, the use of auto-reclosers on the lines are not installed by most discos for line protection but for load management due to poor relay coordination between the discos and TCN. Unfortunately, we have a regulator and technical enforcer who are carried away by their rivalry rather than working together to enforce the codes and standards, and regulations.
The Nigeria distribution code version 2 (NDC. v2), Part 2, Section 4.6 states clearly how the distribution system should be protected, NDC. V2 S4.6.2 states “Discos and TSP shall
cooperate to ensure correct and appropriate settings of protection to achieve effective,
discriminatory isolation of faulty line/equipment within the target time clearance specified by TSP”. NDC. V2 S4.6.3 also states how 33kV line shall be protected.
The real question is, do we use the codes and standards, and regulations as a guide for
technical enforcement and sanctions. These are questions for the Regulator and Technical
enforcer to clarify? It is interesting that the technical enforcer advises or issues an enforcement notice restricting connection to 33kV and directing Users/Discos to provide adequate protection neglecting the dictates of the Nigerian distribution code version 2 (NDC. V2).
Does our technical enforcer use the regulations, codes and standards as a guide while issuing its guidelines, and enforcement notice/order? Whose responsibility is it to enforce NDC. V2, P2, S4.6.1-5? Technical enforcer (NEMSA) or regulator (NERC) or both. If NDC. V2, P2, S.4.6.1-5 is enforced, the reason stated for the ban on 33kV by the technical enforcer might not stand the test of time because all its fear will have been eliminated. Will it not be appropriate that the technical enforcer should call for a stakeholder meeting
quarterly between TCN and Discos to address/resolve the lingering relay protection coordination issues?
When will the technical enforcer and regulator bury their grudges and work together to enforce the grid and distribution codes and standards?
The ban on the 33kV is either here or there because the regulator is busy looking for every avenue to rubbish the action of the technical enforcer by encouraging the discos to disregard the enforcement order/notice of the technical enforcer without looking at the overall merit of the technical issues raised by the technical enforcer.
It is also strongly advised that the technical enforcer should see the NESI as a work in progress and stakeholders should be carried along through workshops, technical sessions and seminars before enforcement notices or orders are published. The industry needs a collective effort not a boss and servant relationship.
The 33kV ban once more exposes the unnecessary rivalry between NERC and NEMSA, this unhealthy rivalry is really killing and affecting the growth of NESI. No proper communication and cooperation between NERC and NEMSA, this encourages the discos and TCN to latch on the lacuna.
NEMSA should learn to accept NERC as the regulator of the NESI and NERC should learn to accept NEMSA as the police of NESI who is saddled with the responsibility to enforce whatever codes and standards, and regulation published while NERC is expected to sanction or appraise any erring player/stakeholder based on the recommendation of NEMSA.
Finally, NERC and NEMSA needs to work together to save the nation from the impending
future electricity expansion crisis if the indiscriminate use of 33kV line as point load is not
address properly.