Electrical Energy

Electrical Charges Electrical Charges and Current Coulmb’s Law Like charges attract, unlike charges repel. Coulmb’s Law

Electric and Hydraulic Analogy Current Flow rate Voltage Elevation Battery Pump Motor Water wheel

Series and Parallel Circuits Same current passes through all devices If one device fails, all fail Parallel Currents add up Devices work independent of each other Fire Hazard

Units Charge C Current A Voltage V Resistance W Energy kWh Power W, kW, MW, GW

Table 1. Power Consumption For Several Household Appliances* Power, W Clock Radio Television (color) Freezer/Refrigerator Hair Dryer Washer (clothes) Vacuum Cleaner Home Computer 2 70 - 400 65 - 200 600 - 1000 1200 - 1800 350 - 500 1000 - 1400 100 - 400 Air Conditioner Coffee Maker Iron Dishwasher Toaster Microwave Oven Dryer (clothes) Oven range 800 - 1000 900 - 1200 1200 - 2400 850 - 1400 800 - 1400 750 - 1100 1800 - 5000 10000 - 12000

Generation of electricity Thermal Powerplants Solar Photovoltaics Thermophotovoltaics Electrically Conductive Plastics Fuel Cells

Fuel Cells

Principle of Operation Electrolysis H2O + electric current  H2+1/2 O2 Fuel Cells H2+1/2 O2 H2O +electric current

Generation

Storage Battery (chemical energy) Ultracapacitor (static energy) Flywheel (rotational energy)

Batteries Batteries are devices that produce electric potentials Primary batteries Secondary batteries Batteries are characterized by: Electrical potential Capacity

Transmission To reduce power loss we must reduce current P=RI2 To reduce current we must transmit power at very high voltages (Since voltage is constant) P=V.I

Transmission Grid

Load and Capacity Base load Peak load Average load Capacity Factor Optimal Size

Load Duration