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8.1 Energy sources (Primary Energy [Sources] (Non Renewable Energy sources…

- - - - Combustion of fossil fuels such as Coal, Oil, Gas releases large amount of gases such as CO2
      - Fossil fuels are created naturally in the earth over a period of millions of years therefor it is not possible to quickly replenish them.
      - Energy released through the combustion of fossil fuels is used to produce high pressure steam that drives a turbine in order to produce electricity.
      - 81% of our energy comes from non renewable sources
    - - Heat energy released from the fission of Uranium-235 nuclei is used to heat heavy water within the reactor which travels through pipes. This heat is transferred to a separate system of water which surrounds the pipes. This water gets heated and is converted to high pressure steam which turns a turbine which in turn turns a generator and produces electricity.
        
        Nuclear energy production produces radioactive nuclear waste which must be stored safely.
  - - - Sunlight, wind, moving water in tides, waves, rivers, rain and geothermal
      - Hydroelectric
        
        gravitational energy → kinetic energy → electric energy
        
        Power lost by water: P= mg∆h/∆t
        
        m/∆t=ρv/∆t
        
        therefore, P=ρvg∆h/∆t)
        
        Benefits
        
        Hydroelectric energy is renewable
        
        It is flexible to electricity demand. Hydroelectric turbines can be started up in a few minutes (unlike thermal electrical energy stations)
        
        It is a clean energy source and produces little or no pollution or greenhouse gases
        
        They have low maintenance, long service lives, and very low-cost operation
        
        They are suitable for both large-scale and local micro-scale electrical energy stations
        
        Drawbacks
        
        They must be located in terrain that allows for the fall of water, possibly far from end-use locations
        
        Hydroelectric dams often involve huge reservoirs, and hence there can be ecological damage in flooding and displacement of people and wildlife
        
        The surface area of reservoirs increases the amount of water loss in a region through evaporation
        
        Silt can accumulate in the reservoir and downstream river flow can be affected
        
        Decay of biological material in the reservoir contributes to methane production and release (especially in tropical climates)
        
        There are potential safety issues when dams hold back huge volumes of water. Sudden flooding from material failures, unusual events such as earthquakes, or sabotage can devastate large areas below the dam
      - WIND TURBINES
        
        Volume of air (V) passes throng the turbine blades over a period of time interval 𝛥t
        
        Mass (m) of air contained within the cylinder is given by
        
        m=𝜌V=𝜌VA𝛥t
        
        If we assume that all of its kinetic energy is transformed into electricity
        
        P=𝛥E/𝛥t
        thus
        P=1/2𝜌AV^3 )
        
        Benefits
        
        Wind can be plentiful and widely available.
        
        It is a clean energy source and produces no pollution or greenhouse gases.
        
        It occupies a small land footprint, often in rural areas.
        
        Wind consumes no water and produces no thermal pollution.
        
        Wind energy is becoming increasingly cost-effective and has low operational costs.
        
        Drawbacks
        
        Reliably high-wind locations may be distant from end-use locations, for example, many miles off-shore.
        
        There are safety issues related to storms and high wind damage to turbine blades.
        
        Many people perceive that wind generators produce noise and visual pollution.
        
        Rotating turbine blades pose some threats to wildlife such as migrating birds.
        
        Wind strength is unpredictable and highly variable.
    - - Solar heating panels
        
        Convert radiant energy of the Sun -> Thermal energy
      - Photovoltaic cells
      - Evaluation
        
        Drawbacks
        
        They only provide energy during the day and depend on the weather.
        
        For maximum effectiveness, panels must track and remain perpendicular to the Sun's rays at all times; tracking systems are costly and size-limited.
        
        Initial installation costs of PV are high, especially for integration with the electrical grid.
        
        Off-grid energy storage for use at night requires expensive batteries.
        
        Benefits
        
        Solar PV and thermal energy can be used in remote areas, far from the electrical grid.
        
        They can be installed in large fields ('solar farms') and business and household rooftops (angled or flat).
        
        Solar PV and thermal are clean and silent. There is no release of harmful chemicals or pollutants.
        
        They are very low maintenance and should last 25
        
        Solar PV and thermal energy are fully renewable; they only need sunlight.
- - - - Formula = Energy stored in fuel / Volume of fuel
  - - - Formula = Energy stored in fuel / Mass of fuel
- - - - Boiler - Transfers thermal energy to superheated steam
      - Turbine- transforms the thermal energy of the steam to kinetic energy
      - Generator- transforms inetic energy to electrical energy
      - Condenser- cools steam to water
- - - - Useful energy output is shown as an arrow pointing to the right, wasted energy is represented as a downwards arrow
      - https://www.youtube.com/watch?v=dAOzDsluIX0