Grade 10 electricity – Generation, Transmission and Distribution of Electricity Quiz

Olkaria in the Rift Valley is the largest geothermal power-producing area in Kenya and supplies a significant portion of the country's electricity from geothermal energy.

Step-up transformers raise voltage so current is lower for the same power, reducing losses during long-distance transmission.

Kenya Power is the utility that distributes electricity to homes and businesses across Kenya; KenGen is mainly a generator.

Hydroelectric plants convert the energy of flowing or falling water into mechanical energy and then electricity using turbines and generators.

Kenya, like most countries in Africa and Europe, uses a mains frequency of 50 hertz for its electrical supply.

400 kV is used for high-capacity long-distance transmission in Kenya; lower voltages like 11 kV are for local distribution.

For a given power, higher voltage means lower current; lower current reduces I^2R losses in transmission lines, making long-distance transmission more efficient.

Geothermal is renewable because it uses Earth's natural heat; diesel, coal and petrol are fossil fuels and not renewable.

Circuit breakers detect faults and automatically open to isolate the faulty section, protecting the rest of the power system.

Load shedding is a controlled measure where supply is temporarily cut to some areas when generation is insufficient to meet total demand, avoiding wider outages.

Distribution substations contain step-down transformers that lower transmission voltages (e.g., 132 kV) to distribution voltages (e.g., 11 kV) for local supply.

Tall towers provide clearance to prevent accidental contact with live conductors and to reduce the risk of arcing to the ground or nearby structures.

I^2R losses are resistive heating losses in conductors and increase with the square of the current flowing through the line.

Lake Turkana Wind Power is a major wind farm in Kenya that generates electricity from wind resources; Olkaria is geothermal and Masinga is hydro.

Distribution transformers step down medium distribution voltages (e.g., 11 kV) to low voltages like 240 V (single-phase) and 415 V (three-phase) for consumer use.

Higher voltages allow the same power to be transmitted with lower current, which reduces I^2R losses over long distances.

Substations contain transformers and switchgear to step voltages up or down and to route and protect power flows within the network.

Diesel and heavy fuel oil are used in thermal plants to provide flexible generation when hydro or other sources are insufficient, though they are costly and polluting.

Earthing directs fault currents safely into the ground, reducing the risk of electric shock and helping protective devices operate correctly.

Grid interconnection allows different regions or countries to exchange power, improving reliability and enabling sharing of generation resources.

Kilowatt-hour is a unit of energy representing power (kilowatts) used over time (hours) and is commonly shown on electricity bills.

At high voltages, the electric field can ionize surrounding air causing a corona discharge, which results in power loss and audible noise.

Underground cables are less exposed to weather and lightning but are more expensive to install and are harder and costlier to repair than overhead lines.

Protection relays monitor electrical quantities and, when they detect abnormal conditions, send signals to breakers to open and protect equipment and people.

Wind and solar vary with weather and time, so the grid needs additional measures (storage, demand management, flexible plants) to keep supply and demand balanced.