Question 1: Define renewable energy and give two examples of renewable energy sources.

Answer: Renewable energy is energy from sources that are naturally replenished on a human timescale, such as solar and wind energy.

Question 2: Explain how solar panels convert sunlight into electrical energy.

Answer: Solar panels use photovoltaic cells to absorb sunlight, which excites electrons and generates electrical current.

Question 3: What is the primary advantage of using wind energy over fossil fuels?

Answer: Wind energy is renewable, produces no greenhouse gases during operation, and reduces pollution compared to fossil fuels.

Question 1: A solar panel has a power output of 250 Watts under ideal sunlight conditions. If it receives sunlight for 6 hours a day, what is the total energy produced in kilowatt-hours (kWh) per day?

Answer: Energy (kWh) = Power (kW) × Time (hours). So, 0.25 kW × 6 hours = 1.5 kWh.

Question 2: A wind turbine has a capacity of 1.5 MW. If it operates at 40% efficiency for 24 hours, how much electrical energy does it generate in megawatt-hours (MWh)?

Answer: Energy = Capacity × Efficiency × Time = 1.5 MW × 0.40 × 24 hours = 14.4 MWh.

Question 1: Describe a simple theoretical experiment to compare the efficiency of solar panels exposed to different angles of sunlight.

Answer: Set up identical solar panels in a fixed area, adjust their angles relative to the sun at different times of day, measure their electrical output over a fixed period, and compare the results to determine the optimal angle for maximum efficiency.

Question 2: Identify two variables that could affect the efficiency of a wind turbine in a practical experiment.

Answer: Wind speed and blade angle.

Question 3: List two safety precautions to consider when designing a theoretical experiment involving renewable energy sources.

Answer: Ensure proper electrical insulation and avoid exposure to high voltage or moving parts without safety measures.

Question 1: A report states that a solar farm produces an average of 5000 kWh of electricity daily. If the farm has 2000 solar panels each rated at 250 W, estimate the average number of sunlight hours per day the panels receive.

Answer: Total power output = Number of panels × Power per panel = 2000 × 0.25 kW = 500 kW. Daily energy = Power × Hours, so Hours = Total energy / Power = 5000 kWh / 500 kW = 10 hours.

Question 2: A wind turbine’s efficiency drops during low wind conditions. Describe how this impacts daily energy production and suggest a method to mitigate this issue.

Answer: Lower wind speeds reduce the turbine’s energy output, decreasing daily production. To mitigate this, turbines can be placed in locations with higher average wind speeds or combined with energy storage systems to balance supply.

Question 1: Explain how renewable energy sources are contributing to reducing pollution and combating climate change.

Answer: Renewable energy sources produce little to no greenhouse gases during operation, reducing air pollution and helping to mitigate climate change by decreasing reliance on fossil fuels.

Question 2: Identify one challenge associated with the large-scale implementation of renewable energy technologies and suggest a possible solution.

Answer: A challenge is the intermittent nature of renewable sources like solar and wind. A solution is to develop efficient energy storage systems to store excess energy for use during low production periods.

Question 1: Discuss the advantages and disadvantages of solar and wind energy as renewable resources, and evaluate their roles in the future energy landscape.

Answer: Advantages of solar and wind energy include their renewability, low operational costs, and minimal environmental impact. Disadvantages encompass their intermittent nature, dependence on weather conditions, and initial setup costs. Both technologies are vital for reducing greenhouse gas emissions, but their integration with energy storage and grid systems is necessary for a sustainable future.