NOTES

• Energy:

  • Energy is the capacity to do work
  • Energy can change between forms, however it is never destroyed or created
• Potential energy types (stored):

  • Chemical
  • Mechanical
  • Nuclear
  • Gravitational
• Kinetic energy types (motion):

  • Movement
  • Electricity
  • Heat
  • Sound
  • Light
• Potential energy:

  • Potential energy is stored in objects not in motion, that will move once released e.g.
  • Water in a reservoir ready to turn a turbine for HEP
  • Pressure in a fire extinguisher
• Kinetic energy:

  • Kinetic energy involves motion and movement e.g.
  • Electricity when travelling throughout a circuit
  • Heat radiating from a fire
• Mechanical storage:

  • Compression
  • Tension
  • Motion
• Chemical storage:

  • Batteries
  • Gases
  • Solid fuel
  • Food
• Pneumatics:

  • Compressed air or gas is used to create movement
  • Pneumatic systems are very accurate and low maintenance
  • Pneumatics are commonly used in industry, for example with mechanical drills and on automated production lines
• Hydraulics:

  • Pumped and compressed liquid is used instead of air which creates a more powerful system and are used in Lifting equipment, Car braking systems, Fire fighter cutting equipment
• Kinetic pumped storage:

  • Hydroelectric power provides a very controllable supply of power
  • When there is a surplus supply of electricity, water is pumped back up to the high-level reservoir
  • Potential energy is stored in the water at the higher level and used when demand is high
• Flywheel energy storage:

  • Flywheels rotate in a near frictionless environment
  • They use surplus energy to reach optimum speed
  • Momentum is stored until it is required
  • The motor used to power them, in turn, becomes a generator which returns electrical energy when needed
  • Kinetic Energy Recovery Systems (KERS) are used on vehicles to save fuel
• Chemical energy storage:

  • Batteries (electro-chemical)
  • Canisters / bottles of gas
  • Flammable gels and liquids including petrol and diesel
  • Hydrogen fuel cells
• Cells and batteries:

  • A battery stores chemical energy in a series of cells
  • Each cell is usually 1.5V (rechargeable cells are 1.2V)
  • Each battery has a positive and negative terminal
• Alkaline batteries:

  • The anatomy of batteries can vary
  • Alkaline batteries are more efficient and have a higher capacity when compared to traditional lead-acid varieties
  • More charge can be stored in the same size battery
  • They hold their charge well
• Rechargeable batteries:

  • There is an ever increasing demand for rechargeable technology in:
  • portable domestic appliances and power tools
  • disability and personal transport
  • hybrid and all-electric vehicles
  • mobile devices
• Emerging battery technology:

  • Flow batteries are large units used to help smooth demand on the National Grid
  • Sodium and glass batteries are super-fast charging and very high capacity
• Disposal of batteries:

  • Batteries contain toxic chemicals and metals which leach into the soil and water table, are harmful to wildlife and the natural habitat and need specialist recycling