Physics – 1.7.3 Energy resources | e-Consult

Solar radiation is the fundamental energy source because it drives nearly all other energy systems on Earth. While geothermal, nuclear, and tidal energy have their own distinct origins, they ultimately trace back to the Sun's energy. Here's a breakdown:

• Solar Energy Harvesting: Plants use solar energy through photosynthesis to create organic matter (biomass). This biomass can then be used directly as fuel (e.g., wood) or indirectly (e.g., fossil fuels formed over millions of years).
• Fossil Fuels: Coal, oil, and natural gas are formed from the remains of ancient plants and organisms. These organisms obtained their energy from the sun through photosynthesis. Therefore, the energy stored in fossil fuels originated from solar radiation.
• Wind Energy: Uneven heating of the Earth's surface by the sun creates differences in air pressure, leading to wind. Wind turbines convert the kinetic energy of the wind (which is driven by solar heating) into electrical energy.
• Hydroelectric Energy: Solar radiation drives the water cycle (evaporation, condensation, precipitation). This water collects in rivers and reservoirs, and the potential energy of the water is converted into kinetic energy as it flows downhill, driving turbines.
• Solar Thermal Energy: Solar thermal systems directly capture solar radiation using solar panels to heat water or air. This heated water or air can then be used for domestic hot water, space heating, or to generate electricity.

Geothermal energy is heat from within the Earth, primarily from radioactive decay. Nuclear energy comes from the splitting of atoms. Tidal energy is from the gravitational pull of the moon and sun on the Earth's oceans. While these are independent sources, their energy origins are ultimately linked to the Sun's initial energy input.