What is a Power System?
By Idowu Oyebanjo
In simple terms, an electric power system is a network of electrical components used to supply, transfer and use electric power. The main objectives of a power system are to meet the present and future demands for electricity by consumers in a cost-effective and publicly acceptable way at defined levels of quality and security of supply. In so doing, the power system must comply with environmental obligations. The electricity services that domestic, commercial and industrial consumers want that are provided by the use of electrical energy include but not limited to illumination, transport, water heating, air conditioning, operation of TV, fridges, radios and other electronic goods, cooking, and smooth running of industrial processes.
Obviously, the starting point for a power system is to have sufficient supply to meet the present demand plus a spare or redundant capacity to ride through system shocks which are inevitable. This in simple terms means that generation capacity must at all times be greater than or equal to estimated demand. This is achieved by having accurate and up-to-date data to carry out robust planning of the power system. Typical planning cycles are 7-year or 10-year forecast of growth in the demand for electricity normally carried out by network planning engineers. For consumers to realise the desired benefits, the power system must maintain voltages within acceptable lower and upper bands (statutory voltage, frequency and power factor limits), avoid sags and surges that could damage equipment or cause flickering of lights, minimise aggregate technical, commercial and collection power losses. Yes, the system must be stable and resilient under stress and function as intended in the face of continuously changing demands and fault conditions. Above all, the cost of energy must be affordable for consumers and at the same time be competitive for businesses, for which I must say, achieving both of these, may at times be in conflict with each other.
Key features of a Power System
At a time when we are talking of cost reflective tariffs, it is no less pertinent to state that the overall intent and purpose of a power system lies in the ability of citizens and users of the commodity to pay for the product. Hence, energy delivery must be affordable. Having said that, there is no reason why a nation cannot provide this as a social service to her citizen if it is buoyant enough and can minimise wastages, looting and corruption. Perhaps a token contribution is all that is required by domestic consumers and a cost reflective tariff regime for industrial and commercial consumers in Nigeria. Make no mistake, the cost of having an efficient power system is huge, but when you consider how much people steal in Nigeria, it should be “a piece of cake” for Nigeria to have a vibrant power system. The experience of consumer must be borne in mind when developing a power system. They must be helped to accept the introduction of new prices, technology and policies. To achieve this, consumers need to be well-informed. Their views must be held important because they are the most important stakeholders in a power system. As such, introducing “anything new” (be it prices, technology or policy) into the power system should neither be excessively burdensome nor intrusive to consumers.
Quality of Supply
A power system needs to produce electricity for users at acceptable levels of quality for them to benefit from its use. Users of electricity have equipments which operate satisfactorily at defined boundaries of voltage, frequency, waveform, harmonic content and power factors. The power system must therefore maintain its operation reasonably within certain bands to meet these requirements. For a most enjoyable experience, consumers should not become irritated by the flickering of lights, voltage dips, and surges that damage their equipment or stall very sophisticated industrial and research processes.
Security of Supply
A power system needs to be able to have sufficient supply of energy to meet its demand as well as have spare capacity to manage contingencies which will occur in the day-to-day running and operation of the system. To this end, adequate supply of fuel to generate enough electrical energy cannot be over-emphasised. Fossil fuel presents itself as a suitable form of energy that can be converted into electricity because of the natural endowment of Nigeria. Thermal power plants require gas, oil, or coal as major sources of energy and Nigeria has these in abundance. Other sources of energy include nuclear, geothermal, waste, landfill gas, to mention but a few. More environmentally friendly and renewable sources of energy will include solar, wind, wave and Hydro(i.e run of water). A nation has to tap into the available sources of energy within its domain or seek to buy from elsewhere to meet its domestic energy needs at any given time. In this regard, Nigeria has failed woefully. There can be no significant development of infrastructure and economy without this as the energy consumption of a nation is directly proportional to its economic relevance in today’s world. A portfolio of energy mixes backed by visionary energy policies is thus required to harness or unlock the economic potential of a nation in darkness like Nigeria. But the security of supply means more than having sufficient supply of energy, it also involves its stability and resilience under fault and changing demand conditions. To achieve this, a set of policies and standards for safe design, operation, maintenance and control of the network will be required. Furthermore, the power system which is secured must be immune to malicious disruption, theft of copper and distributed electricity, and be flexible to accommodate changing requirements which may be driven by national policies from time to time. A secure power system is one which punishes errant participants and those who run foul of the extant rules. In the case of Nigeria, a special court to prosecute offenders who undermine the safety and integrity of the power system is necessary to differentiate the requirements of the power system from the current judicial system where “anything goes”!
In today’s climate, there should be no mention of developing a power system without due consideration of the impact on the environment. The world is currently embarking on an ambitious decarbonisation objectives which require the consideration of using alternative forms of energy to fossil fuel in the generation of electricity. In this regard, generation from solar, waste (human and bio-mass), wind, wave, should be part of the energy mix for Nigeria but by no means the focus for accelerated development of the power system in the short-to-medium term. A country that cannot secure its borders cannot be trusted with the security of lethally dangerous raw-materials for nuclear power generation such as uranium. In the hands of mere agitators or disenfranchised individuals, destruction of significant levels will take place. Also, the years of neglect of general practice of safety in the wider Nigerian system require that the pursuit of nuclear power generation be reviewed. I believe the international community will not allow Nigeria anyway.
In my opinion, the most important asset in a power system are the humans working in the system. All other components cannot function without them. For a power system to function sustainably, it needs abundant supply of human capital. This asset should be given at least an equal value as the material asset such as transformers, cables, lines, substations, technology and so on. Strategy for maintaining adequate level of manpower must be integral to the development of a power system. Such strategy should as a minimum include localisation of the industry, apprenticeships, training, and retraining of staff, and robust systems for workforce renewal.
Idowu Oyebanjo MNSE CEng MIET