1. ENERGY BASICS Aim: To give a clear understanding of concepts, terms and units of energy Energy Forms and Conversions Energy and Power Conversion Efficiency Energy Terminology

2. WHY? Energy terms are used interchangeably

3. ENERGY AND POWER Definitions and Units Power is rate at which energy is converted or transmitted Unit: Watt Symbol: W Energy and Power are related

4. ENERGY AND POWER Definitions and Units Energy is the ability or capacity to do work Energy is about quantities Units: Joule Symbol: J(calories/BTU’s)

5. ENERGY AND POWER Units for Electricity Energy = Power x time = kW x h= kWh 1 kWh = 1 kW device running for 1 hour = 3.6 MJ

6. Orders of Magnitude of Energy and Power 1 kW - Power Rating of an electric hot plate 10 kW -Power Rating of small tractor/power tiller 1 MW -Rated power output of small power station serving a town of approximately 20,000 people 1 kWh - Roughly energy consumed by electric hot plate in one hour 1 MWh -Roughly energy needed to drive a car 1000 kilometers 9 TWh -Approximate amount electricity used in Zambia annually

7. Energy Forms Kinetic Energy Potential Energy Thermal (Heat) Energy…………………

8. Energy Forms (Cont.) Chemical Energy Electrical Energy Electromagnetic Energy (Radiation) Mechanical Energy

9. Energy Conversions Energy can be converted from one form to another First Law of Thermodynamics In any energy transformation the total quantity of energy is conserved

10. Conversion Efficiency

11. ConverterEnergy Input form Energy Output Form % Efficiency Petrol Engine ChemicalMechanical20 - 25 Solar CellLightElectrical8 - 15 Hydro Turbine PotentialMechanical70 - 99

12. Energy Chain

13. Biomass Energy Chain