1 Training Session on Energy Equipment Electricity Presentation from the “Energy Efficiency Guide for Industry in Asia” © UNEP 2006 Electrical Equipment/ Electricity

2 © UNEP 2006 Training Agenda: Electricity Future electricity scenario Generation & distribution Phase of electricity Active and reactive power Power factor correction Electrical load management Electrical billing mechanisms Transformers Electrical Equipment/ Electricity

3 © UNEP 2006 Electricity Development can be measured by a nation’s electricity consumption Electricity usage is divided into: a)Industrial b)Commercial and residential c)Agriculture and irrigation Electricity important input for industry General Electricity Scenario Electrical Equipment/ Electricity

4 © UNEP 2006 Electricity International Energy Agency predicts for 2030: 78% of population in developing countries has access to electricity 1.4 billion people no access 665 billion US$ needed to overcome this General Electricity Scenario Electrical Equipment/ Electricity

5 © UNEP 2006 Electricity How can electricity supply shortage be solved? a)Renovation and modernization of plants, transmission and distribution systems b)Demand side management with the utilization of energy efficiency technologies c)Awareness raising among energy users General Electricity Scenario Electrical Systems/ Electricity

6 © UNEP 2006 Electricity Electricity generation: fossil fuels and uranium Renewable energy is growing Generation & Distribution Electrical Systems/ Electricity Renewable 21% Nuclear 16% Fossil fuels 63% World electricity generation by energy (US Energy Information Administration, 2004)

7 © UNEP 2006 Electricity Electrical Systems/ Electricity Generation & Distribution Generator 10.6 KV GT 220 KV Step down transformer Distribution Power plant Transmission system Distribution system

8 © UNEP 2006 Electricity AC generators (“alternators”) generate electricity Electricity generated at 9-13 KV Power generated from 67.5 to 1000 MW Power stations: generating transformers (GTs) to increase voltage to KV Substations: step-down transformers to reduce voltage before distribution Electrical Systems/ Electricity Generation & Distribution

9 © UNEP 2006 Electricity Benefits of high voltage transmission Less voltage drop: good voltage regulation Less power loss: high transmission efficiency Smaller conductor: lower costs Electrical Systems/ Electricity Generation & Distribution

10 © UNEP 2006 Electricity Single phase AC circuit: Two wires connected to electricity source Direction of current changes many times per second Phase of Electricity Electrical Systems/ Electricity 3-phases of an electric system (Wikipedia contributors, 2005) Three phase systems: 3 lines with electricity from 3 circuits One neutral line 3 waveforms offset in time: cycles/second

11 © UNEP 2006 Electricity Star connection Phase of Electricity Electrical Systems/ Electricity Delta connection

12 © UNEP 2006 Electricity Active power (kW): real power used Reactive power (kVAR): virtual power that determines load/demand Utility pays for total power (kVA) Active and Reactive Power Electrical Systems/ Electricity Source: OIT kVA =  (KW) 2 + (KVAR) 2

13 © UNEP 2006 Electricity Power Factor Correlation Electrical Systems/ Electricity Figure: Power factor of electric circuit

14 © UNEP 2006 Electricity kVAR demand should be as low as possible for the same kW output PF Correction: Capacitors Electrical Systems/ Electricity Figure: Capacitor as kVAR generator

15 © UNEP 2006 Electricity Act as reactive power generators Reduce reactive power Reduce total power generated by the utilities PF Correction: Capacitors Electrical Systems/ Electricity Figure: Fixed capacitor banks Source: Ecatalog

16 © UNEP 2006 Electricity Advantages for company: One off investment for capacitor Reduced electricity costs: Total demand reduced No penalty charges Reduced distribution losses Increased voltage level at load end, improved motor performance PF Correction: Capacitors Electrical Systems/ Electricity

17 © UNEP 2006 Electricity Advantages for utility: Reduced reactive component of network Reduced total current in the system from the source end Reduced I2R power losses Reduced need to install additional distribution network capacity PF Correction: Capacitors Electrical Systems/ Electricity

18 © UNEP 2006 Electricity Goal: reduce maximum electricity demand to lower the electricity costs Load curve predicts patterns in demand Electrical Load Management Electrical Systems/ Electricity Daily load curve of an engineering industry (National Productivity Council, India) KVA Hours

19 © UNEP 2006 Electricity Strategies to manage peak load demand: Shift non-critical / non-continuous process loads to off-peak time Shed non-essential loads during peak time Operate in-house generation or diesel generator (dg) sets during peak time Operate AC units during off-peak times and utilize cool thermal storage Install power factor correction equipment Electrical Load Management Electrical Systems/ Electricity

20 © UNEP 2006 Electricity Energy charges Actual charges based on active power Charge based on apparent power Maximum demand charges Based on maximum demand registered Penalty for peak load Electricity Billing Mechanism Electrical Systems/ Electricity

21 © UNEP 2006 Electricity Power factor penalty or bonus Fuel costs Electricity duty charges Meter rentals Lighting & fan power consumption Time of Day (TOD) rates Electricity Billing Mechanism Electrical Systems/ Electricity

22 © UNEP 2006 Electricity Electricity Billing Mechanism Electrical Systems/ Electricity Utility uses trivector meter for measurement during billing cycle (usually month): Maximum demand Active energy in kWh Reactive energy in kVArh Apparent energy in kVAh

23 © UNEP 2006 Electricity Electricity Billing Mechanism Electrical Systems/ Electricity Demand measured in time intervals Maximum demand is highest reading Customer charged on highest maximum demand value! A Typical Demand Curve (National Productivity Council)

24 © UNEP 2006 Electricity Static electrical device that transforms electrical energy from one voltage level to another Two or more coils linked magnetically but electrically insulated Transformer Electrical Systems/ Electricity Turns Ratio: turns on 2nd coil (connected to load) turns on 1 st coil (connected to power source) Figure 12: A view of a transformer (Indiamart.com)

25 © UNEP 2006 Electricity Transformers are classified based on: Input voltage Operation Location Connection Transformer types Electrical Systems/ Electricity

26 © UNEP 2006 Electricity Transformer losses: constant and variable Best efficiency: load where constant loss = variable loss Transformer Losses & Efficiency Electrical Systems/ Electricity Transformer loss versus percent loading (BEE, 2004) P TOTAL = P NO-LOAD + (% Load/100) 2 x P LOAD P TOTAL = P NO-LOAD + (Load KVA/Rated KVA) 2 x P LOAD P TOTAL = P NO-LOAD + (% Load/100) 2 x P LOAD P TOTAL = P NO-LOAD + (Load KVA/Rated KVA) 2 x P LOAD

27 © UNEP 2006 Electricity Electricity Formulae Electrical Systems/ Electricity Resistance (Ohm) Voltage (Volts) Reactance Impedance Real power (Watt) Reactive power Apparent power Power factor Efficiency Transformer ratio Voltage drop in a line Star connection Delta connection

28 Training Session on Energy Equipment Electricity THANK YOU FOR YOUR ATTENTION © UNEP GERIAP Electrical Systems/ Electricity

29 Electrical Systems/ Electricity © UNEP 2006 Disclaimer and References This PowerPoint training session was prepared as part of the project “Greenhouse Gas Emission Reduction from Industry in Asia and the Pacific” (GERIAP). While reasonable efforts have been made to ensure that the contents of this publication are factually correct and properly referenced, UNEP does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of this publication. © UNEP, The GERIAP project was funded by the Swedish International Development Cooperation Agency (Sida) Full references are included in the textbook chapter that is available on