Sustainable Energy: Production and Use

Sustainable Energy

Week 13, Class 2. 5/1

Game Plan

  • Recap and completion of the previous lecture.

  • Concept of sustainable energy.

  • Types and harnessing of renewable energy.

Announcements

  • Think piece interactive activity 3: Tuesday 5/6.

  • Completion of course evaluation & final exam review: Thursday 5/8.

  • Assignment 2 due Today 5/1.

Sustainable Energy

  • Energy sources and strategies that meet current demand without compromising future energy needs.

  • Sustainable energy = Energy efficiency + renewable energy.

Energy Efficiency

Energy Efficiency and Conservation

  • Energy efficiency: Obtain a given result or amount of output while using less energy input.

  • Energy conservation: Methods of energy conservation.

    • Individual lifestyle changes to reduce energy consumption.

Energy Conservation Methods

  • Cogeneration in power plants.

  • Sustainable building design.

  • Example: Heat Recovery Unit

    • Hot exhaust gases are used to generate steam and hot water for heating and cooling campus buildings.

    • Components: Gas Turbine, Generator, Electricity, Fuel

Renewable Energy Potential

  • Potential energy from renewable resources (exajoules per year).

  • World energy use comparison:

    • World: >1600

    • Solar: 619

    • Wind: 600

    • Geothermal: 500

    • Biomass: >250

    • Hydro: 50

    • Ocean: <1

Renewable Energy Consumption in the U.S.

  • U.S. Consumption:

    • Petroleum: 36%

    • Natural Gas: 33%

    • Coal: 10%

    • Nuclear Electric Power: 8%

    • Renewable Energy: 13%

      • Hydroelectric: 18%

      • Wind: 29%

      • Biofuels: 18%

      • Wood: 16%

      • Solar: 14.2%

      • Geothermal: 1.6%

      • Biomass Waste: 3%

  • U.S. Electricity Generation from Renewable Energy:

    • Fossil Fuel: 60%

    • Renewables: 21%

      • Wind: 47.5%

      • Hydropower: 26.8%

      • Solar: 18.5%

      • Bioenergy: 5.3%

      • Geothermal: 1.8%

Types of Renewable Energy

  • Bioenergy/Biomass

    • Releases no net CO2CO_2 into the atmosphere.

    • Generates electricity (biopower).

    • Processed into liquid fuel for automobiles (biofuel).

      • Ethanol and biodiesel.

    • Can be harnessed through gasification.

Ethanol Production from Corn

  • Example of farm corn use to produce ethanol.

Growth of Ethanol Production (1980-2013)

  • Significant increase in billion gallons per year for both World and United States.

Hydroelectric Power

  • Harnessed through the kinetic energy of surface water.

  • Techniques Employed:

    • Dammed water hydro.

    • Pumped-storage hydro.

    • Run-of-river hydro.

  • Example: Lower Granite Dam on the Snake River - Washington

Top Producers of Hydroelectric Power (Terawatt Hours)

  • China: 1,300

  • Brazil: 380.85

  • Canada: 362.82

  • United States: 257.69

  • Russia: 214.53

  • India: 160.33

  • Norway: 143.09

  • Japan: 77.64

  • Sweden: 71.46

  • Turkey: 55.7

Solar Energy

  • Passive solar energy collection

    • Buildings are designed to maximize absorption of sunlight in winter and keep interior cool in the summer.

    • Derived from the sun.

Solar Energy Collection

  • Active solar energy collection

    • Use devices to focus, move, or store solar energy.

      • Photovoltaic cells (PV).

      • Concentrated solar power technique (CSP).

    • Advantages: no fuel use, quiet, no emission of GHG.

Spatial Distribution of Solar Radiation in U.S. (kWh/m²/year)

  • Varies significantly across different regions.

Wind Energy

  • Harnessed with the use of wind turbines.

  • Off-shore wind farms harness more wind power than land-based farms.

  • Produces no emissions.

  • Example: Wind Turbine

Global Wind Energy Production

  • Major Producers:

    • China: 37%

    • Germany: 16%

    • United States: 8%

    • India: 5%

    • Spain: 4%

    • Rest of World: 30%

  • Trend of U.S. Price of Electricity from Wind (cents/kWh) and Global Wind Power Capacity (gigawatts).

  • Price decrease over time.

  • Production increased over time.

U.S. Wind Generating Capacity, 2022 (Megawatts)

  • Texas has highest wind power capacity: 37,422 MW.

  • Followed by Iowa: 12,427.7 MW

  • Oklahoma: 11,991.9 MW

  • Kansas: 8,244.7 MW

  • California: 7,037.2 MW.

Geothermal Energy

Geothermal energy rises from beneath Earth’s surface and can be harnessed directly through geysers or drilling wells to capture heated ground water and steam, used for heating buildings or driving industrial activities. Examples include geysers at the surface and Earth’s internal structure, with geothermal power plants utilizing this energy.

  • Energy that rises from beneath Earth’s surface.

  • Can be harnessed directly on Earth’s surface through geysers or drilling wells to capture heated ground water and steam.

  • Used for heating buildings or driving industrial activities.

  • Examples: Geysers at the surface and Earth’s internal structure.

Geothermal Power Plants

  • Geothermal power plants:

    • Use heat from Earth's interior to produce steam, which drives turbines to generate electricity.

    • Located in areas with high geothermal gradients, typically near tectonic plate boundaries, volcanic hotspots, or regions with geothermal reservoirs close to the surface.

Ocean Energy Sources

  • Harnessed through kinetic energy of ocean water or temperature of water.

  • Can be harnessed in the following ways:

    • Tidal energy: derived from movement of water during different tides.

Ocean Thermal Energy Conversion (OTEC)

  • Experimental stage.

  • Utilizes temperature differences in ocean water.

    • Warm Seawater (26°C) at the surface.

    • Cold Seawater (5°C) at 1000m depth.

Hydrogen

  • Can be produced from water or other matter.

  • An energy carrier.

  • Can be used to power fuel cells and generate electricity or other types of usable energy.

  • Example: Hydrogen fuel cell.

Summary

  • Sustainable energy involves the practice of energy efficiency and use of renewable energy.

  • Renewable energy has very little negative impacts on the environment.