Renewable Energy Overview

Definition of Renewable Energy

Energy from sources that won't run out, replenished faster than consumed.
Utilizes natural power sources: sun, wind, tides, and organic materials (biomass).

Solar Energy
- Solar panels convert sunlight to electricity via the photoelectric effect.
- Photons absorbed; electrons released, creating an electric current.
Wind Energy
- Wind turbines capture wind movement to generate electricity.
- Offshore turbines are more efficient than onshore due to stronger winds.
Hydropower
- Water flows through turbines to generate electricity.
- Power depends on water volume and height difference from source to outflow.
Bioenergy
- Generated from organic matter (biomass) such as plants and waste.
- Two types:
  - Dry Biomass: Burned in boilers (e.g., wood pellets).
  - Wet Biomass: Rotting waste produces methane (biogas) captured for energy.
Geothermal Energy
- Taps into underground steam and hot water.
- Involves drilling wells to harness heat for electricity generation.

Addresses climate change: fossil fuels contribute to greenhouse gas emissions.
Over 80% of global energy still from fossil fuels.
Global temperatures increased by approximately 1.1°C since the late 19th century, leading to extreme weather events.
Achieving net zero is crucial: carbon emissions removed must equal those added.

Solar, wind, and hydropower: zero emissions during electricity generation but some emissions during infrastructure construction.
Bioenergy emits carbon when burned, but absorbs CO2 during biomass growth.
Deforestation concerns with solar farm building impact on carbon absorption.

Costs for solar and wind energy decreasing annually.
Consumers can save on electricity bills with residential solar panels and energy storage.
Potential savings of $12 trillion globally by 2050 from renewable energy adoption.

As of late 2022, nearly 40% of the UK's electricity was generated by renewables.
Governments must invest more in renewables to cut carbon emissions and combat climate change.