Overview of the Energy System

Dr. James Doss-Gollin

Thu., Sep. 5

Announcements

  1. If you’re interested in attending the study abroad orientation on 9/11 at noon, please email Dr. Bedient by the end of the week.
  2. This is a big class. Please consider coming to office hours! (Freshmen: the sophomores have already figured this out)

Climate Change and \(\text{CO}_2\)

Today

  1. Climate Change and \(\text{CO}_2\)

  2. Emissions and Energy Use

  3. Energy Sources

  4. Electricity Systems

  5. Wrapup

Global CO2 emissions over time at Mauna Loa Observatory, Hawaii

Emissions: rate of change

  • Temperature depends on atmospheric concentration (“climate sensitivity”)
  • Emissions are the rate at which greenhouse gases are added to the atmosphere
  • Greenhouse gases leave the atmosphere through biological (e.g., photosynthesis) and physical (e.g., equilibrium with the ocean) processes
  • Imbalance when emissions exceed sinks

Climate sensitivity

Climate sensitivity is the equilibrium change in global temperature for a doubling of \(\text{CO}_2\) concentrations.

  • With no feedback effects at all, about \(1^\circ\) C
    • Both positive and negative feedbacks
  • Doubling CO2 leads to \(\approx 3^\circ\) C of warming (“climate sensitivity”)
    • But values between 1.5 and 4.5 C are plausible

CO2 emissions over time

Emissions and Energy Use

Today

  1. Climate Change and \(\text{CO}_2\)

  2. Emissions and Energy Use

  3. Energy Sources

  4. Electricity Systems

  5. Wrapup

Energy Sources

Today

  1. Climate Change and \(\text{CO}_2\)

  2. Emissions and Energy Use

  3. Energy Sources

  4. Electricity Systems

  5. Wrapup

Pre-industrial energy sources

  • Wood
  • Other biomass
  • Animal power
  • Small windmills

Origin of fossil fuels

Gas

Oil

  1. Plants and animals die and sink to the bottom of the sea
  2. The plant and animal layer gets covered with mud
  3. Over time, more sediment exerts pressure, compressing the dead plants and animals into oil
  4. Oil moves up through porous rocks and eventually forms a reservoir
  1. Anaerobic decomposition of microorganisms (e.g., phytoplankton and zooplankton) under anoxic conditions
  2. Over geologically long duration, high levels of heat and pressure caused the organic matter to chemically alter into liquid and gaseous hydrocarbons

Origin of fossil fuels (cont.)

Coal

  1. Vegetation was gradually compressed as they get buried under soil, rising the temperature and pressure
  2. The plant matter was protected from biodegradation and oxidation, usually by mud or acidic water, and the dead vegetation was slowly converted, by carbonization, to coal

Global coal reserves

Global oil reserves

Nuclear

  • Fission: Splitting atom nuclei releases energy
  • Heat from fission boils water to create steam
  • Steam drives turbines to generate electricity
  • Low carbon
  • Modern systems generally safe, but high upfront costs

Hydro

  • Uses flowing water to generate electricity
  • Water stored in dams or from rivers turns turbines
  • Provides reliable baseload power
  • Low carbon emissions
  • Can impact local ecosystems and communities

Solar

200MW solar farm in Wingate, TX
  • Converts sunlight directly into electricity
  • Photovoltaic cells or concentrated solar power
  • Zero emissions during operation but requires land
  • Rapidly decreasing costs
  • Intermittent, requires energy storage solutions

Wind

  • Harnesses wind energy to generate electricity
  • Wind turbines convert kinetic energy to electrical
  • Clean, renewable energy source
  • Increasingly cost-competitive
  • Variable output, dependent on wind conditions

Brazos Wind Ranch, TX

Overview of energy system

Electricity Systems

Today

  1. Climate Change and \(\text{CO}_2\)

  2. Emissions and Energy Use

  3. Energy Sources

  4. Electricity Systems

  5. Wrapup

Electrification: Key to Mitigation

  • Electrification is crucial for climate change mitigation
  • Renewable electricity can replace fossil fuels in many sectors
  • Enables use of clean energy sources across the economy
  • Transportation: Electric vehicles
  • Heating: Heat pumps
  • Industry: Electric furnaces and processes

Triple renewable capacity

Global renewables power capacity in the Net Zero Emissions by 2050 Scenario, 2022 and 2030

Where do these estimates come from?

Example: IEA’s Net-Zero by 2050 Roadmap.

  1. Scenario Development : Multiple global policy and socioeconomic storylines
  2. Energy System Modeling : Detailed analysis of energy production, consumption, and technologies
  3. Integrated Assessment Models (IAMs) : Economic and emissions impacts of scenarios
  4. Climate Models : Temperature projections based on emissions scenarios
  5. Technology Pathways : Analysis of technology development and deployment

Note

Note: Most models have limited feedback from climate to economics/policy

Some definitions

  • Primary energy: Total energy content of fuel before conversion
  • Final energy: Energy delivered to end-users
  • Efficiency in conversion and use is crucial
  • Renewables replace the work done by fossil fuels, not total primary energy
  • Higher efficiency of electric systems means less primary energy needed
  • Example: Electric vehicles vs. internal combustion engines

Carbon intensity of electricity

Renewable energy price declines

  • Solar PV module prices declined exponentially
  • Learning rate for solar PV modules: 20.2%
  • Price declined from $106 to $0.38 per watt (99.6% decrease)

Learning curves in renewable energy

  • Solar electricity prices follow learning curves
  • Learning rate for solar electricity: 36%
  • Wind power also shows strong learning effects

Which is which: NY, TX, and VT?

Electricity demand variability

Electricity demand is not constant

Extreme weather impacts on the grid

Extreme temperatures drive rare peaks in electricity demand

Wrapup

Today

  1. Climate Change and \(\text{CO}_2\)

  2. Emissions and Energy Use

  3. Energy Sources

  4. Electricity Systems

  5. Wrapup

Questions

On Canvas (here), please share at least one thing you’d like to learn more about

Project 1

See here for details