Making Use of Energy

Making Use of Energy

Energy Conservation and Efficiency

• Energy conservation refers to reducing energy usage by turning off unnecessary lights or appliances and improving insulation with energy-efficient windows or loft insulation.
• Energy efficiency is achieving the same output using less energy, like using LED bulbs instead of incandescent bulbs, which provide the same light using significantly less electricity.
• Energy management systems help to monitor and control energy usage, reducing wastage and improving efficiency.
• Passive solar building design uses the building layout and materials to capture and distribute solar energy effectively, reducing the need for additional heating or cooling.

Different Forms of Energy

• Energy comes in different forms, including heat, light, motion, electrical, chemical, nuclear, and gravitational. These forms can be transformed from one into another.
• The principle of conservation of energy states that energy cannot be created or destroyed, only converted from one form to another. This is fundamental for understanding energy conversions.

Energy Transformations

• In any energy transformation, not all energy is converted into the desired form. Some is often wasted, generally as heat. For example, in a car engine, only about 20% of the energy in petrol is converted to motion.
• Energy flow diagrams or Sankey diagrams can visually represent energy transformations and indicate how much energy is wasted.

Heat Transfers

• Heat can be transferred via conduction, convection, or radiation. Conductors, like metals, transfer energy quickly, while insulators, like wool, slow it down.
• Conduction occurs mainly in solids, where heat energy is transferred by the vibrations of particles.
• Convection is heat transfer in fluids (liquids and gases) where hot, less dense material rises, and cool, denser material sinks.
• Radiation is heat transfer via electromagnetic waves, and unlike conduction and convection, it can occur in a vacuum.

Work Done and Power

• Work is done when a force moves an object. The amount of work done depends on the force applied and the distance moved.
• Power is the rate of doing work or converting energy. The more work done in a given time, or the faster the rate of energy conversion, the greater the power.

Renewable and Non-Renewable Energy

• Non-renewable energy sources, like fossil fuels, cannot be replacing after they are used. They also often contribute to carbon dioxide emissions and climate change.
• Renewable energy sources, like solar, wind, hydro, and geothermal, are naturally replenishing and have less environmental impact.
• A sustainable energy strategy includes increasing energy efficiency, reducing energy demand, and increasing the share of energy from renewable sources.