Lecture 9 Energy and Power Systems Transition

Gang He

March 24, 2025

Sample analytic questions

• What are the drivers of energy transition?
  
• How should each country think/design/implement its energy transition?
  
• How to frame the role of different technologies in energy transition?
  
• How geo-politics, wars, and pandemic impact the energy in transiton?
  

Transition history

RE > coal: a milestone

U.S. power-sector half-way to zero

Soft path vs. hard path

Central, large scale, incresing supply/demand
Fossil, nuclear

Flexible, resilient, sustainable, and benign
Renewable energy, energy efficiency, matching in scale and quality to the end use need

Drivers of energy transition

• Demand
• Supply
• Climate change
• Environmental pollution
• Energy security
• Economics

100% reneables: a debate

100% renewables (wind, water, solar) for all purposes?

• Resources, technology, economic ready
  
• Huge benefits

100% renewable not viable/necesssary?

• Modeling errors
  
• Implausible assumptions
  
• Need better modeling

Energy transition is difficult, broad technology portfolio is needed

Changing perspectives of renewables

Energy Transition: The German Energiewende

• Fighting climate change
• Reducing energy imports
• Stimulating technology innovation and the green economy
• Reducing and eliminating the risks of nuclear power
• Energy security
• Strengthening local economies and providing social justice

Germany: role of nuclear?

Three operating plants, total capacity 4055MW, in 2022, scheduled to shut down by end of 2022, and were extended to 2024.

The U.S.: net zero America

U.S.: IRA

Denmark: Distributed generation (CHP and wind)

China: the scale and scope

China: phasing out coal

Phasing out coal yields huge (water savings, avoided pre-matual death, and health) co-benefits, however, need to address employment impact and welfare redistribution

Bazil: role of hydro and biofuel

Africa: the fogotten billion

Summary

• Diverse factors that drive energy transition
  
• Common and differentiated solutions to energy
  
• Leverage the advantages
  
• Addressing uncertainties: geopolitics, wars, pandemic, and more

Sample power system transition analytic questions

• How much solar and wind capacity need to be built?
  
• How cost delince of renewables and storage will change the capacity and generation mix of the power sector?
  
• How much new transmission capacity is needed to harvest the benefits of interconnection?
  
• Does CCS has role to play in the power sector decarbonization?
  

Power sector’s central role

Overarching strategy

• Electrification
  
• Decarbonization

Why power sector is special?

• Essential good
  
• Infrastructure
  
• Technology/network complexity: balance on real-time
  
• Supply/Demand inelasticity
  
  • Capital intensive
    
  • Investment takes time
    

U.S. electricity flow

U.S. transmission grid

Refresh the basics

• Energy and power
  
• kW, MW, GW, TW
  
• Heat rate and efficiency (Carnot, 1st, 2nd)
  
• Thermodynamics

Load factor and load curves

\(LF=\frac{Energy\ consumed}{Energy\ at\ peak\ demand}=\frac{Average\ power}{Peak\ power\ demand}\)

A low load factor means a “peaky” load shape

Supply curve and dispatch

Power system modeling family

Type	Production Cost (Unit Commitment and Dispatch)	Network Reliability (AC Power Flow, Dynamics)	Capacity Expansion
Generator Adequacy	Yes	No	Often
Flexibility Requirement	Yes	No	Somewhat
Transmission Adequacy	Partially	Yes	Typically No
Gen Contingencies	Somewhat	Yes	No
Transmission Contingencies	Somewhat	Yes	No
Frequency Stability	Somewhat	Yes	No
Voltage Stability, Voltage control	No	Yes	No
Examples	PROMOD, GE-Maps, PLEXOS, GridView	Positive sequence load flow (PSLF), power system simulator for engineering (PSSE)	NEMS, ReEDS, SWITCH, Grid-path, GenX, PyPSA, Haiku

Capacity expansion models

• Capacity expansion models simulate generation and transmission capacity investment, given assumptions about future electricity demand, fuel prices, technology cost and performance, and policy and regulation
  
• What mix of generators should we build to meet load?
  
• Does a policy affect cost of service regions and competitive regions in different ways?

Strength and limits

• Strength: Examine the impacts of power sector policies (or alternative technology/fuel trajectories) on the generation and capacity mix in the mid-to long-term
  
• Limits: Many do not have chronological unit commitment (i.e., every hour of the year chronologically); some use aggregate (model) plants for dispatch; transmission and power flow are a stylized representation (transport or DC)
  
• Example questions: Quantifying the impacts of environmental policies on generation and capacity? What are the cost implications of alternative pathways to a low greenhouse gas emissions future? How will alternative future prices of natural gas impact capacity investment? What is the change in consumption and expenditures? What are the efficiency and distributional effects of various policy designs?

SWITCH Model as an example

Typical output: capacity/generation mix

Typical output: transmission expansions

Unit committment and network reliability

• Unit Commitment Model: Simulate detailed (hourly to sub-hourly) operation of a given system; Assess resource adequacy and other aspects of reliability of a system; Analyze the impact of changes in the system (e.g., retirement/addition of capacity) on system operation; Assess transmission congestion and locational marginal prices; Describe the daily pattern of emissions
  
• Network Reliability Model: Detailed simulations of the transmission network including dynamic events that can occur in seconds (and cause big problems); these models aren’t run on a day to day basis –they are only run to examine significant changes to an existing system

Emerging trends

• Smart grid
  
• Distributed generation
  
• Renewable penetration
  
• Efficiency improvement
  
• Electrifying
  
• DR/DSM

Summary

• Power sector’s central role in decarbonization
  
• Capacity expansion model to analyze the optimized investment decisions
  
• Decisions in the real world is much more complicated
  
• Emerging trends in the power sector

References

Clack, Christopher T. M., Staffan A. Qvist, Jay Apt, Morgan Bazilian, Adam R. Brandt, Ken Caldeira, Steven J. Davis, et al. 2017. “Evaluation of a Proposal for Reliable Low-Cost Grid Power with 100% Wind, Water, and Solar.” Proceedings of the National Academy of Sciences, June, 201610381. https://doi.org/10.1073/pnas.1610381114.

Cui, Ryna Yiyun, Nathan Hultman, Diyang Cui, Haewon McJeon, Sha Yu, Morgan R Edwards, Arijit Sen, et al. 2021. “A Plant-by-Plant Strategy for High-Ambition Coal Power Phaseout in China.” Nature Communications 12 (1): 1–10. https://doi.org/10.1038/s41467-021-21786-0.

He, Gang, Jiang Lin, Froylan Sifuentes, Xu Liu, Nikit Abhyankar, and Amol Phadke. 2020. “Rapid Cost Decrease of Renewables and Storage Accelerates the Decarbonization of China’s Power System.” Nature Communications 11 (1): 2486. https://doi.org/10.1038/s41467-020-16184-x.

He, Gang, Jiang Lin, Ying Zhang, Wenhua Zhang, Guilherme Larangeira, Chao Zhang, Wei Peng, Manzhi Liu, and Fuqiang Yang. 2020. “Enabling a Rapid and Just Transition Away from Coal in China.” One Earth 3 (2): 187–94. https://doi.org/10.1016/j.oneear.2020.07.012.

Jacobson, Mark Z., Mark A. Delucchi, Mary A. Cameron, and Bethany A. Frew. 2015. “Low-Cost Solution to the Grid Reliability Problem with 100% Penetration of Intermittent Wind, Water, and Solar for All Purposes.” Proceedings of the National Academy of Sciences 112 (49): 15060–65. https://doi.org/10.1073/pnas.1510028112.

Johnston, Josiah, Rodrigo Henriquez-Auba, Benjamı́n Maluenda, and Matthias Fripp. 2019. “Switch 2.0: A Modern Platform for Planning High-Renewable Power Systems.” SoftwareX 10: 100251. https://doi.org/10.1016/j.softx.2019.100251.

Lovins, Amory B. 1976. “Energy Strategy: The Road Not Taken.” Foreign Affairs 55: 65. https://rmi.org/insight/energy-strategy-the-road-not-taken.

Masters, Gilbert M. 2013. Renewable and Efficient Electric Power Systems. John Wiley & Sons.

Mulugetta, Yacob, Youba Sokona, Philipp A Trotter, Samuel Fankhauser, Jessica Omukuti, Lucas Somavilla Croxatto, Bjarne Steffen, et al. 2022. “Africa Needs Context-Relevant Evidence to Shape Its Clean Energy Future.” Nature Energy, 1–8. https://doi.org/10.1038/s41560-022-01152-0.