Renewable energy comes from natural processes that are replenished on a human timescale. This lesson introduces the idea of renewability, the main source types, and why renewable energy matters for climate, health, and energy access.
Renewable energy is energy derived from natural processes replenished faster than they are consumed. Sunlight, wind, flowing water, Earth’s heat, and biological material are common examples. These resources are renewed through ongoing natural cycles rather than being used up on a human timescale.
All flashcards
What is renewable energy?
Energy from natural processes replenished faster than they are consumed, such as sunlight, wind, flowing water, and Earth’s heat.
What does variable renewable energy mean?
Renewable generation that fluctuates with conditions such as weather or time of day; solar and wind are examples.
Name three renewable sources that can often be controlled or scheduled.
Reservoir hydropower, bioenergy, and geothermal energy can often be scheduled to help meet demand.
How do renewable, low-carbon, and sustainable differ?
Renewable describes replenishment; low-carbon describes greenhouse gas emissions; sustainable describes broader long-term effects on people and the environment.
Why is biomass not always sustainable or climate-neutral?
Burning biomass releases carbon dioxide, and poor sourcing or inadequate regrowth can leave emissions uncompensated and damage ecosystems.
Quiz questions
Why is conventional nuclear power generally not classified as renewable?Answer: It uses mined uranium, a finite fuel.
What distinguishes photovoltaic technology from solar thermal technology?Answer: Photovoltaics convert light directly into electricity.
Before accounting for turbine limits, how does theoretical wind power change if wind speed doubles?Answer: It rises by a factor of eight.
How does pumped-storage hydropower store energy?Answer: It uses electricity to pump water uphill for later generation.
What does sector coupling link with the electricity system?Answer: Transport, buildings, and industry.
Based on the Wikipedia article Renewable energy, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.