Lesson Notes By Weeks and Term v4 - SHS 1
Energy Efficiency and Conservation
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Energy Efficiency and Conservation
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Subject: Engineering
Class: SHS 1
Term: 2nd Term
Week: 3
Grade code: 1.2.3.LI.2
Strand code: 2
Sub-strand code: 3
Content standard code: 1.2.3.CS.1
Indicator code: 1.2.3.LI.2
Theme: Ene rgy Systems
Subtheme: Energy Efficiency and Conservation
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--- Overview and Learning Objectives
Part A: The Core Ideas - Efficiency vs. Conservation
It is very important to understand the difference between these two terms. Energy Conservation: This is the act of reducing energy consumption through behavioural changes. It simply means using less energy. Example: Turning off the lights when you leave a room. Example: Unplugging your phone charger when your phone is fully charged. Example: Taking a shorter shower to use less hot water. Analogy: If you have one bowl of gari, conservation means eating only half of it so you have some for later. Energy Efficiency: This means using technology that requires less energy to perform the same function. You are getting the same result, but with less energy input. Example: Replacing an old, yellow incandescent bulb with a modern, white LED bulb. Both light up the room, but the LED uses up to 80% less electricity. Example: Using a modern "Gyapa" coal pot instead of a traditional one. Both cook your banku, but the Gyapa stove is designed to use less charcoal to produce the same amount of heat. Analogy: Finding a new way to cook your gari that makes the one bowl feel as filling as two bowls. You get the same satisfaction from less input.
Why does this matter? To know if a new LED bulb is *truly* more efficient, we need proof. That proof comes from measurement. Part B: Measuring Electrical Quantities
To measure energy use, we must first measure the fundamental electrical quantities. The three most important for our purpose are Voltage, Current, and Power. Voltage (V) What it is: Voltage is the 'electrical pressure' or 'push' that causes electricity to flow in a circuit. Think of it like the water pressure in a pipe. Unit: Volts (V) Instrument: Voltmeter. How to Connect: A voltmeter is always connected in parallel (across) the component you want to measure. Current (I) What it is: Current is the rate of 'flow' of electric charge. Think of it like the amount of water flowing through the pipe per second. Unit: Amperes (A), often called "Amps". Instrument: Ammeter. How to Connect: An ammeter is always connected in series (in the path of) the circuit. You have to 'break' the circuit to insert the ammeter. Electrical Power (P) What it is: Power is the rate at which electrical energy is used by a device. This is the most important value for understanding energy efficiency. A device with a higher power rating uses more energy per second. Unit: Watts (W) How to Calculate: You can calculate power by multiplying voltage and current. Formula: `Power (P) = Voltage (V) × Current (I)` Instrument: A Wattmeter measures power directly. However, we can easily calculate it if we have a voltmeter and an ammeter.