Renewable Energy Study Guide

This set of flashcards covers key concepts related to types of renewable energy, their advantages and disadvantages, and comparisons with non-renewable energy sources.

Solar Energy: Definition and Generation

1. What: Energy captured from the sun's electromagnetic radiation.

2. How:

   • Photovoltaics (PV): Uses semiconductors to convert sunlight directly into electricity.

   • Solar Thermal: Uses mirrors or collectors to concentrate sunlight to heat fluids for power.

Solar Energy: Advantages

1. Renewable: It is an inexhaustible resource as long as the sun exists.

2. Maintenance: Low operational and maintenance costs after the initial setup.

3. Clarity: Produces no direct noise or air pollution during operation.

Solar Energy: Disadvantages

1. Intermittency: Energy production stops during the nighttime or heavy cloud cover.
2. Storage: Requires expensive battery systems to provide a continuous power supply.
3. Space: Demands significant land area for industrial-scale energy production.

Solar Energy: Optimal Locations

1. Latitude: Low-latitude regions closer to the equator where sun angles are most direct.
2. Climate: Arid deserts with minimal cloud interference.
3. Irradiance: High solar irradiance zones such as the Southwestern United States or the Sahara.

Wind Energy: Definition and Generation

1. What: Energy harnessed from the kinetic movement of air masses.
2. How: Wind flows over turbine blades, creating lift that turns a shaft connected to a generator to produce electricity.

Wind Energy: Advantages

1. Clean: No direct emissions or water consumption required for power generation.
2. Space Efficiency: Farm owners can still use the land under turbines for agriculture or grazing.
3. Renewable: Driven by atmospheric pressure changes caused by the sun.

Wind Energy: Disadvantages

1. Intermittency: Wind speeds are not constant, leading to fluctuating energy output.

2. Wildlife: Poses a physical threat to birds and bats due to blade collisions.

3. Aesthetics: Often criticized for visual impact and low-frequency noise.

Wind Energy: Optimal Locations

1. Geography: Open plains and high-altitude mountain ridges.
2. Coastal: Offshore areas where wind is stronger and more consistent than on land.
3. Gaps: Mountain passes that funnel air through narrow corridors.

Hydropower: Definition and Generation

1. What: Energy derived from the gravitational force of moving or falling water.
2. How: Water from a reservoir or river flows through a dam to spin large turbines connected to generators.

Hydropower: Advantages

1. Reliability: Provides a steady, consistent "base load" of power compared to solar or wind.
2. Flexibility: Water flow can be adjusted quickly to meet peak electricity demands.
3. Multipurpose: Reservoirs can be used for irrigation, recreation, and flood control.

Hydropower: Disadvantages

1. Ecosystems: Dams block fish migration and alter the natural temperature and chemistry of the water.
2. Displacement: Large reservoirs often flood valleys, forcedly displacing local human and animal populations.
3. Drought Risk: Generation is dependent on precipitation and snowmelt levels.

Hydropower: Optimal Locations

1. Topography: Mountainous regions with significant elevation changes (high head).
2. Hydrology: Areas with large, fast-flowing rivers.
3. Infrastructure: Geologically stable areas capable of supporting massive dam structures.

Geothermal Energy: Definition and Generation

1. What: Thermal energy generated and stored within the Earth's crust.
2. How: Steam or superheated water is pumped from underground reservoirs to drive turbines at the surface.

Geothermal Energy: Advantages

1. Constant: Available 24/7 regardless of weather conditions or time of day.
2. Footprint: Requires very little land space compared to solar or wind farms.
3. Efficiency: Highly efficient for both large-scale power and residential heating.

Geothermal Energy: Disadvantages

1. Location-Limited: Only accessible in specific regions with high tectonic activity.
2. Emissions: Can release small amounts of hydrogen sulfide and trace CO_{2}.
3. Stability: Over-extraction can lead to land subsidence or localized seismic activity.

Geothermal Energy: Optimal Locations

1. Tectonics: Near tectonic plate boundaries or "hot spots" (e.g., Iceland or the Ring of Fire).
2. Features: Areas with active geysers, hot springs, or volcanic activity.
3. Geology: Regions with thin crustal layers where magma is closer to the surface.

Biomass and Biofuels: Definition and Generation

1. What: Energy produced from organic matter such as wood, agricultural waste, and algae.
2. How:
   • Combustion: Burning wood or waste for heat.
   • Fermentation: Converting plant starches into biofuels like ethanol.

Biomass and Biofuels: Advantages

1. Waste Reduction: Converts landfill waste and agricultural byproducts into useful energy.
2. Carbon Cycle: Can be carbon-neutral if the plants grown for fuel absorb as much CO_{2} as is released.
3. Storage: Energy is stored chemically and can be used whenever needed.

Biomass and Biofuels: Disadvantages

1. Pollution: Burning biomass releases particulate matter and nitrogen oxides.
2. Land Use: Large-scale biofuel production competes with food crops for arable land and water.
3. Efficiency: Energy density is lower than fossil fuels or nuclear power.

Biomass and Biofuels: Optimal Locations

1. Agriculture: Regions with high crop production (e.g., the U.S. Midwest for corn-ethanol).
2. Forestry: Areas with active timber and paper industries for wood waste.
3. Urban: Near large cities to utilize municipal solid waste.

Nuclear Power: Definition and Generation

1. What: Energy released from the bonds holding the nucleus of an atom together.
2. How: Nuclear Fission splits heavy atoms (Uranium-235) to release heat, which boils water to create steam for turbines.

Nuclear Power: Advantages

1. Density: Extremely high energy density; small amounts of fuel produce massive power.
2. Zero Emissions: Does not release CO_{2} or air pollutants during the fission process.
3. Reliability: Can operate at full capacity for months at a time without stopping.

Nuclear Power: Disadvantages

1. Waste: Produces hazardous radioactive waste that requires secure storage for thousands of years.
2. Safety: Risks of catastrophic accidents (meltdowns) if cooling systems fail.
3. Resources: Relies on Uranium, which is a finite, non-renewable mineral.

Nuclear Power: Optimal Locations

1. Cooling: Proximity to large bodies of water (oceans, lakes, or rivers) for reactor cooling.
2. Stability: Geologically stable land far from earthquake fault lines.
3. Demographics: Typically placed in remote areas but within reach of high-demand power grids.