Question 1: Define renewable energy resources and give two examples.

Answer: Renewable energy resources are natural resources that can be replenished naturally in a short period of time. Examples include solar energy and wind energy.

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

Answer: Solar panels convert sunlight into electricity through the photovoltaic effect, where sunlight excites electrons in the solar cells, generating an electric current.

Question 3: What is the main reason for the increasing use of wind energy worldwide?

Answer: Because wind energy is renewable, environmentally friendly, and cost-effective as technology advances.

Question 1: Calculate the amount of energy produced in kilowatt-hours (kWh) by a solar panel system rated at 5 kW operating for 6 hours daily. Use the formula: Energy (kWh) = Power (kW) × Time (hours).

Answer: Energy = 5 kW × 6 hours = 30 kWh

Question 2: A country’s energy consumption data shows a 20% increase in solar energy use over five years. If the current use is 50 terawatt-hours (TWh), what was the solar energy use five years ago?

Answer: Previous use = Current use / 1.20 = 50 TWh / 1.20 ≈ 41.67 TWh

Question 3: Based on recent reports, wind energy accounts for 15% of total energy consumption, which is 400 TWh annually. How much energy (in TWh) is produced by wind energy each year?

Answer: Wind energy = 15% of 400 TWh = 0.15 × 400 = 60 TWh

Question 1: Describe a simple experiment to compare the efficiency of solar panels and wind turbines in generating electricity. Include variables to control and safety precautions.

Answer: An experiment can involve setting up a solar panel and a small wind turbine in the same environment. Measure the electrical output under similar conditions (e.g., sunlight and wind speed). Control variables include the exposure area, angle, and environmental conditions. Safety precautions include handling electrical components carefully, ensuring no water contact with electrical parts, and avoiding working near moving parts or electrical hazards.

Question 2: Identify three variables that would affect the efficiency of a solar power system in real-world conditions.

Answer: Variables include sunlight intensity, angle of the solar panels, and temperature of the panels.

Question 1: A report states that global wind energy capacity doubled over the past decade, reaching 650 GW. Discuss the potential impact of this trend on reducing reliance on fossil fuels.

Answer: The doubling of wind energy capacity indicates a significant shift towards renewable sources, which can reduce greenhouse gas emissions, decrease reliance on fossil fuels, and promote sustainable energy development. This trend may also lead to economic benefits and increased technological innovation.

Question 2: Identify one challenge associated with increasing the use of renewable energy resources such as solar and wind power.

Answer: Intermittency and variability of sunlight and wind make consistent energy supply challenging.

Question 3: Explain how advancements in battery storage technology can influence the trends in renewable energy use.

Answer: Improved battery storage allows excess renewable energy to be stored and used when production is low, making renewable sources more reliable and encouraging greater adoption.