Unit 5 Study Guide: Renewable Energy and Waste Management

Unit 5 Study Guide: Renewable Energy and Waste Management

☀ PART 1: RENEWABLE ENERGY OVERVIEW

⚡️ Energy Sources

• Renewable: replenished naturally (solar, wind, water, geothermal, biomass)

• Nonrenewable: finite (fossil fuels, nuclear)

🌍 Global Energy Consumption

• 81% from fossil fuels (petroleum, natural gas, coal)

• Major shift toward renewable expected due to climate concerns

⚠ Fossil Fuel Impacts

• Air pollution (CO2, NOx, SO2)

• Global warming

• Ocean acidification

🌬 PART 2: WIND ENERGY

💨 How Wind Power Works

• Wind turbines capture kinetic energy from wind

• Converts it into electricity via a generator

• Driven indirectly by the sun

⚖ Evaluating Wind Power Claims

“Wind power is inefficient”

• Capacity factor: wind ~35-40%; coal ~90%

• Wind doesn't blow constantly, but turbines can operate ~65-80% of the time

• Battery storage helps offset intermittency

• Wind complements solar (often blows at night)

“Wind turbines cause harmful noise”

• Sound exists, but very low just a few hundred meters away

• WHO: no evidence of harm to mental/physical health

• "Wind turbine syndrome" is not medically recognized

“Wind turbines use rare minerals"

• Rare earths improve turbine performance

• New models use fewer rare minerals

• Rare earth elements aren't necessarily rare in availability

“Wind uses more energy than it produces”

• Turbines recover energy used to build them in 3–7 months

📈 Wind Power Stats

• ~1% of global energy, but fastest-growing renewable (24% annually)

• U.S.: 3.5% of electricity

• Cost: ~$0.03 per kWh

• EROI: ~20

📅 Future of Wind

• Cost down 90% in 25 years

• Projected to reach 10% global energy

☀ PART 3: SOLAR ENERGY

💡 Types of Solar Tech

• Passive: natural light/heating (no mechanical devices)

• Active:

  • Photovoltaic (PV) panels

  • Solar water heaters

  • Concentrated solar power (CSP)

➕ Advantages

• Available anywhere

• Few emissions

• No CO2 or air pollution

➖ Disadvantages

• High up-front cost

• Manufacturing uses energy and hazardous materials

  • Still cleaner than fossil fuels

  • Offset within ~2 years

• Intermittent and regional effectiveness

🌿 PART 4: BIOMASS ENERGY

🌱 What Is Biomass?

• Energy from plant material, indirectly from sun via photosynthesis

• Types:

  • Wood, charcoal, crop waste, ethanol, biodiesel

• Releases CO2 when burned, but plants also absorb CO2 while growing

➕ Advantages

• Carbon neutral (if managed sustainably)

• Lower nitrogen/sulfur emissions than fossil fuels

• Widely distributed

➖ Disadvantages

• Can compete with food supply

• Inefficient crops

• Land clearing and harvest energy reduce net benefits

💭 PART 5: HYDROPOWER

🚧 Sources & Production

• Powered by the sun-driven hydrologic cycle

• Most used renewable: 38-39% of global renewable energy

• Methods:

  • Impoundment: dams & reservoirs

  • Run-of-river: diverts flow without large dam

➕ Advantages

• Fuel/pollution-free

• Cheap operation

• Provides flood control, water storage, continuous power

➖ Disadvantages

• Land loss, ecosystem disruption

• High initial cost

📊 Future Development

• ~20% of global potential already tapped

• New dams less likely due to costs/impacts

• Existing dams being upgraded

🌊 PART 6: OCEAN ENERGY

⛵ Sources

• Tides (moon-driven)

• Waves (kinetic energy)

• Ocean Thermal Energy Conversion (OTEC): still experimental

➕ Advantages

• Fuel/pollution-free

➖ Disadvantages

• Ecosystem disruption

• Limited locations

• High cost

🏛 PART 7: GEOTHERMAL ENERGY

🔥 Sources

• Heat from Earth's interior

• Methods:

  • Dry steam, flash steam, binary-cycle, ground-source heat pumps (GSHP)

➕ Advantages

• Reliable, inexpensive

• Low pollution

➖ Disadvantages

• May release underground gases

• Can be overused (limited heat)

• High start-up cost, regional limitations

📊 Future Use

• New installations growing 10–20% per year in the U.S.

• Reinjection efforts to sustain source

🚮 PART 8: WASTE MANAGEMENT (Chapter 17.1–17.3)

♻ Why It Matters

• Average American: 1,600 lbs/year (~4.4 lbs/day)

• Proper disposal protects human health and the environment

🚿 Types of Waste

🏠 1. Solid Waste

• Municipal (MSW): homes, schools, small businesses

  • Paper, food scraps, yard waste, plastic, etc.

• Industrial (ISW): factory/process waste before reaching consumer

  • 7.6 billion tons/year in the U.S.

☠ 2. Hazardous Waste

• Flammable, corrosive, explosive, or toxic

• EPA categories:

  • Source-specific (e.g. refineries)

  • Nonspecific (e.g. solvents)

  • Discarded commercial chemicals

• Often overlooked: household hazardous waste

🩸 3. Biomedical Waste

• From hospitals/clinics

• Includes tissues, blood, medical tools

• Must be incinerated or sterilized

🔄 What Happens to Waste?

♸️ Option 1: Sanitary Landfills

• Prevent methane, groundwater contamination, and pests

• Lined with clay & plastic

• Leachate: chemical-filled water

• Covered with clay; methane can be tapped for energy

• ⚠ Not sustainable long-term

🔥 Option 2: Incineration & Waste-to-Energy

• Reduces volume by ~95%

• Uses filters/scrubbers to reduce emissions

• Some generate electricity

♻ Option 3: Reuse and Recycle (covered later)

🚛 Disposal of Hazardous Waste

• Permanent storage: monitored sites

• Chemical processing: break down toxins

• Bioremediation: use of living organisms