PRESENTER PETER NJENGA CHIEF ENGINEER, CUSTOMER SERVICE, KENYA POWER EAST AFRICAN POWER INDUSTRY CONVENTION 2012

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1 PRESENTER PETER NJENGA CHIEF ENGINEER, CUSTOMER SERVICE, KENYA POWER EAST AFRICAN POWER INDUSTRY CONVENTION 2012

2 Introduction Power reliability Power Quality Harmonics Distortion Poor power factor Circuit over load Defective installations Load factor Electricity billing-tariffs CONCLUSION

3 The aim of a power utility company is to supply safe and reliable electricity to its customers 24/7 This may be hampered by breakdown on lines and equipment's Defective installations poor power factor Harmonic distortions load factor and overloading of the circuits

4 This is affected negatively by power outages To improve reliability most organizations have resulted in installation of back up in the form of generators or even solar systems Power outages are categorized into three different phenomena, relating to the duration and effect of the outage: A transient fault, A brownout or sag and A blackout

5 Power distribution lines automation. underground cabling Building new Primary/Secondary substations Building redundant lines

6 the term describes the quality of the voltage rather than power or electric current The parameters that constitute poor power quality are; Overvoltage Variations in the frequency. Variations in the wave shape (harmonics). Non zero low-frequency impedance

7 Through a Demand Side Management (DSM) department we address poor power quality by; Regular power quality measurements and analysis at the primary sub-stations Providing technical advice/assistance through carrying out energy audits. Promoting cost-effective industrial energy efficiency and conservation (EE&C) measures. Carrying out measurements and analysis on the performance of energy saving devices. Encouraging and promoting DSM initiatives by industrial, commercial and domestic customers.

8 Mostly arise from modern electronic equipment e.g. adjustable speed drives and variable frequency drives, battery chargers, UPS, and any other equipment powered by switched-mode power supply (SMPS) equipment. The SMPS are also referred to as non linear loads In an electrical distribution system harmonics create: Overheating of standard electrical supply transformers Cause large load currents in the neutral wires of a 3 phase system.

9 Ensure that power from the primary substation is filtered carrying out power quality analysis for customers with a view to ascertain their harmonic levels Kenya power is in the process of formulating a legal framework to surcharge customers whose harmonic levels are poor.

10 the reactive power (kvar) should be as low as possible for the same kw output in order to minimize the total power (kva) demand. Good pf reduces the electricity cost for the customer as well as increasing available capacity from the electricity distribution network

11 can be improved by installing power factor correction capacitors to the plant s power distribution system. through, Integrated Customer Service (ICS) system the company detects, on monthly, basis customers operating at poor power factor. Kenya power sponsors Energy Management Award (EMA) - an initiative of KAM-CEEC, done to recognize Large power customers that have embraced EE and realized energy and Cost savings- eliminating power factor surcharges.

12 Overloading exert undue strain on the distribution network For current transformer (CT) metered supplies, overloads result to operation of CTs at currents that are outside the linear range and hence leading to commercial losses.

13 Integrated Customer Service (ICS) system is able to detect, on monthly, basis customers exceeding their authorized demand Customers that have exceeded their demand are advised to regularize for the additional load within 30days. Excess loads should be disconnected until the process of additional load is completed.

14 Customers are contractually bound to avoid any kind of; defective wiring, interfering with CTs, meter damage and/or meter tampering so as to avoid unauthorized /fraudulent use of electricity. Cases of defective installations are normally dangerous, lead to high commercial losses, huge bills adjustments and at times long legal battle with the power utility companies.

15 Regular inspection of large power consumers ICS system is able to detect, on monthly, basis supplies that have had a + or - 30% consumption deviation. Automatic Meter Reading-Telemeter Reading The company is also undertaking wide spread loss reduction campaigns

16 A good load factor implies a more constant rate of electrical use better load management at the user end helps to minimize peak demands on the utility infrastructure and improve the utilization of power plant capacity. A low load factor may indicate fraudulent metering or interference with billing Low load factor could also be attributable to lesser hours of operation.

17 may indicate that metering interferences occurred during the month leading to low Kw of maximum demand. This also contributes to commercial losses. could be attributed to other factors, for instance, the plant could be operating, throughout the billing cycle, on near maximum Kw or operation at poor power factor (Kw=kVA P.F).Corrective action must thus be taken.

18 Some of the ways by which a consumer may improve on the load factor are; Arranging work schedules/ shifts to reduce peak load by shifting some electrical use to other time periods. Using interlocks, to prevent simultaneous operation of selected equipment. Using demand controllers, to limit Kw demand in facilities where some power loads can be deferred. Adding, off-peak, energy usage. customers are advised accordingly on how, to deal with cases of low and or high load factor/s at their premises.

19 Utilities often apply a two-part tariff structure in their electricity bills for medium and large enterprises: Energy Charges Maximum Demand Charges

20 Other components of electricity bills may include: Power factor penalty or bonus rates Fuel cost Electricity duty charges Meter rentals Lighting and fan power consumption Time Of Day (TOD-High and Low) rates

21 The company through, ICS system is able to detect, on monthly, basis supplies that have consumptions outside the contracted tariff range. If a metering upgrade/ modification of meter board will be required for the customer to move to the new tariff range, they are advised accordingly. The customers are generally advised to undertake; DSM, correct their power factor and to generally adopt Energy Efficiency and Conservation practices in their operations.

22 Though they are a minority (they constitute 4500 out of a total customer base of about 2 million) yet they contribute more than 50% of the electricity sales. Due to their demand level, the power quality and reliability is more critical for them. They also pose service delivery challenges due to lack of adequate supply of power. Other challenges encountered by large power users are poor power factor charges, overloading of system resulting in blackouts and billing problems. Kenya power has employed various methods to counter the challenges including use of AMR, demand side management, advising customers to install power factor correction equipment, installation of capacitor banks at primary substations to filter the harmonics as well as educating large power customers on how to use energy more efficiently

Chapter 3.1: Electrical System

Part-I: Objective type Questions and Answers Chapter 3.1: Electrical System 1. The heat input required for generating one kilo watt-hour of electrical output is called as. a) Efficiency b) Heat Rate c)