Wind Power

    OCR
    GCSE

    Wind power involves the transduction of the kinetic energy of moving air into electrical energy via the mechanical rotation of a turbine connected to a generator. As a renewable energy source, it is critical for candidates to understand its role in decarbonization while critically evaluating its limitations regarding intermittency and reliability. Assessments require a balanced analysis of environmental impacts, contrasting global benefits (reduced greenhouse gas emissions) with local drawbacks (noise, visual impact, and land use conflicts).

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    Objectives
    4
    Exam Tips
    4
    Pitfalls
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    Key Terms
    5
    Mark Points

    What You Need to Demonstrate

    Key skills and knowledge for this topic

    • Award 1 mark for identifying the energy transfer sequence: Kinetic energy of air → Kinetic energy of turbine blades → Electrical energy in the generator
    • Credit responses that define 'renewable' strictly as an energy resource that is replenished at a rate equal to or faster than it is used
    • Award 1 mark for stating that wind turbines produce zero carbon dioxide or greenhouse gas emissions *during operation*
    • Candidates must explain 'unreliability' specifically in terms of intermittency: wind speed is variable and does not always match grid demand
    • Award 1 mark for linking the location of wind farms (offshore/hills) to higher average wind speeds and reduced visual impact on populations

    Example Examiner Feedback

    Real feedback patterns examiners use when marking

    • "You correctly identified wind as renewable, but you must define *why* (replenished as used) to gain the mark"
    • "Good calculation of power output; ensure you show the rearrangement of the efficiency formula for full method marks"
    • "You mentioned 'pollution'—be specific. Did you mean greenhouse gases, noise, or visual intrusion?"
    • "To access Level 3 in evaluations, you must compare wind's reliability directly with a base-load source like nuclear or gas"

    Marking Points

    Key points examiners look for in your answers

    • Award 1 mark for identifying the energy transfer sequence: Kinetic energy of air → Kinetic energy of turbine blades → Electrical energy in the generator
    • Credit responses that define 'renewable' strictly as an energy resource that is replenished at a rate equal to or faster than it is used
    • Award 1 mark for stating that wind turbines produce zero carbon dioxide or greenhouse gas emissions *during operation*
    • Candidates must explain 'unreliability' specifically in terms of intermittency: wind speed is variable and does not always match grid demand
    • Award 1 mark for linking the location of wind farms (offshore/hills) to higher average wind speeds and reduced visual impact on populations

    Examiner Tips

    Expert advice for maximising your marks

    • 💡When evaluating environmental impact, explicitly state 'during operation' to avoid losing marks for ignoring manufacturing emissions
    • 💡For 6-mark evaluation questions, structure your answer using the 'SEE' method: State the feature, Explain the consequence, Evaluate the significance (e.g., intermittency requires backup stations)
    • 💡Distinguish clearly between 'energy density' (low for wind) and 'power output' when comparing with nuclear sources
    • 💡In calculation questions involving wind power, ensure you convert time units (e.g., hours to seconds) before using P = E/t unless kW/kWh are specified

    Common Mistakes

    Pitfalls to avoid in your exam answers

    • Stating 'wind turbines cause no pollution' without qualification; examiners require distinction between atmospheric pollution (CO2/SO2) and visual/noise pollution
    • Confusing 'renewable' with 'reusable' or 'recyclable'; credit is only given for the concept of natural replenishment
    • Failing to mention the generator; students often incorrectly imply the blades directly produce electricity without the intermediate induction step
    • Vaguely stating 'it is expensive' without specifying high initial construction costs versus low running/fuel costs

    Study Guide Available

    Comprehensive revision notes & examples

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    Key Terminology

    Essential terms to know

    Energy transduction (Kinetic to Electrical)
    Renewable vs Non-renewable resource classification
    Reliability, intermittency, and capacity factors
    Environmental and socio-economic impact analysis
    Mechanics of electrical generation (Generator Effect)

    Likely Command Words

    How questions on this topic are typically asked

    State
    Describe
    Calculate
    Evaluate
    Suggest

    Practical Links

    Related required practicals

    • •{"code":"PAG P4","title":"Investigating Energy Resources","relevance":"Experiments investigating how blade angle or number of blades affects the output voltage of a model wind turbine"}

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