Energy Resources and Sustainability

Classifications

• Renewable resources can be replenished or regenerated in a human timeframe
• Nonrenewable resources cannot be replenished or regenerated in a human timeframe

Energy Resources

• Energy is the capacity to do work
• Energy sources include nuclear, fossil fuels, geothermal, hydro, wind, solar, and biomass

Renewable Resources

• Examples given are geothermal and hydro
• A renewable resource can be replenished or regenerated in a human timeframe

Nonrenewable Resources

• Examples given are nuclear and fossil fuels
• A nonrenewable resource cannot be replenished or regenerated in a human timeframe

Fossil Fuels

• Fossil fuels are the remains of plants and animals that died millions of years ago
• They are the world's primary energy source supporting transportation, electricity, and industries.
• Fossil fuels are abundant and have a lower cost of production compared to other energy resources
• They are considered nonrenewable due to the millions of years required for their formation
• Types of fossil fuels are coal, oil (petroleum), and natural gas

Coal

• Coal is a black, combustible rock made up of carbon, hydrogen, oxygen, nitrogen, and varying amounts of sulfur
• Coal formation starts in a swamp near a sedimentary basin
• Natural phenomena cause water levels to rise, vegetation is destroyed
• Plant debris accumulates and is buried under mud and sand
• Sedimentation layers slow decomposition
• Pressure and heat transform plant debris into coal

Petroleum (Oil)

• Petroleum comes from Latin words petra (rock) and oleum (oil)
• It is a naturally occurring, liquid hydrocarbon
• It is found in geological formations beneath the Earth's surface
• Derived from large quantities of algae and plankton

Natural Gas

• Natural gas is a naturally occurring hydrocarbon gas mixture primarily composed of methane
• Considered Earth's cleanest fossil fuel, is odorless and colorless in its natural state
• Produced from sedimentary rock formations through a process forcing chemicals, water, and sand into a well under high pressure

Oil and Natural Gas Formation

• Dead plants and animals accumulate on land and at sea
• They sink to the sea or lake floor and mix with dirt and microorganisms
• Over tens of millions of years, accumulated organic material decomposes by microorganisms into organic compounds called kerogen
• Rocks rich in kerogen are source rocks
• Heat and pressure transform kerogen into oil and natural gas
• Oil and natural gas migrate and accumulate under specific conditions
• Condition 1: Beneath a dome-shaped, dense cap rock layer
• Condition 2: In a porous reservoir rock where they're trapped

Hydropower

• By the 1700s, water mills were used for pumping, irrigation, and milling
• The Industrial Revolution and its demand for energy drove development of hydroelectric energy production methods
• William George Armstrong developed the first hydroelectric power scheme in 1878, used to power a single lamp
• Electricity and hydraulics played a key role in the development of hydropower
• Hydroelectric energy is created by harnessing the power of moving water, usually by restricting water flow to specific areas

Parts of a Hydropower System

• Dam: Creates a waterfall and stores water for constant supply
• Penstock: Channels water from the reservoir to the turbines
• Powerhouse: Houses the turbines driven by the waterfall and the generator powered by the turbines

Types of Hydropower Plants

• Impoundment Facility: Uses a dam to store water and release it for electricity generation
• Diversion/Run-of-River Facility: Redirects river water through a small dam into pipes towards a penstock and then downhill to the power station
• Pumped Storage: Combines a small storage reservoir with a system to cycle water back into the reservoir after turbine use

Benefits of Hydropower

• Low Operating Costs: Cheap to operate because it doesn't require raw materials
• Less Greenhouse Gas: Emits less greenhouse gas than burning fossil fuels
• Renewable: Meaning it will never run out as long as rivers keep flowing
• Other Uses: Reservoirs created by dams have other uses beyond electricity generation

Drawbacks of Hydropower

• Flooding Land for Reservoirs
• Destroys local wildlife and displaces villages
• Environmental impacts
• Many fish species need to move upstream to lay their eggs, which can be impossible due to dams
• Fish ladders can be partially effective, but sometimes local environmental agencies need to transport fish up and down in trucks

What can be done to reduce greenhouse gas emmissions from HEP?

• Build dams on river systems with fewer nutrients to discourage microbes from decomposing trees
• Build smaller dams in steeper valleys to flood less land

Water Resources

• Physical Attributes of water: Solid, liquid, gas
• Groundwater: Found underground in the cracks and spaces in soil, sand, and rock. Stored in aquifers.
• Aquifer: A body of rock and sediment saturated with water, allowing water movement
• Artesian Well: A free-flowing water well where pressure in the aquifer forces water to the surface without a pump
• Saturated Zone: The zone where all pores and rock fractures are filled with water located below the unsaturated zone.
• Unsaturated Zone: The zone not fully filled with water, lying above the saturated zone
• Surface Water: Found on the Earth's surface in lakes, rivers, and reservoirs
• Perennial: Always present, year-round water sources
• Ephemeral: Temporary water sources, only present during specific conditions like rain
• Man-Made: Artificially created water bodies like reservoirs and canals
• Water is an expensive commodity comparable to gasoline

Important Products from Water Resources

• Domestic water: for drinking, cooking, cleaning
• Industrial water: for manufacturing and production processes
• Agricultural water: for irrigation and farming
• Medical water: for medical procedures and pharmaceuticals

Human Activities and the Water Cycle

• Human activities (settlements, industry, and agricultural development) can disturb the natural water cycle by
  • Diverting land use
  • Modifying water use/reuse
  • Discharging wastes into natural groundwater and surface water pathways