Pioneering NREL Analysis Empowers Los Angeles in Its Pursuit of 100% Renewables

Los Angeles is a famously sprawling metropolis, spanning from the sparkling Pacific Ocean on its west to the rugged San Gabriel and Santa Ana mountains and San Joaquin Hills on its east.

LA's power system is equally expansive: the Los Angeles Department of Water and Power (LADWP) is the nation's largest municipal utility, serving more than 4 million residents over 465 square miles, with more than 3,600 miles of transmission lines to move electricity into the city and more than 10,400 miles of distribution lines to deliver power to customers.

LADWP's footprint extends beyond the city itself, with transmission lines stretching across much of the western United States to tap into valuable energy resources in the Pacific Northwest, Rocky Mountains, and Desert Southwest.

To find equitable and economic local solutions to the climate crisis, the City of Los Angeles has set ambitious goals to transform LA's electricity supply, aiming for a 100% renewable energy power system by 2045, along with a push to electrify the buildings and transportation sectors.

Over the course of 2016 and 2017, the Los Angeles City Council passed a series of motions directing LADWP to develop and implement research partnerships with the U.S. Department of Energy (DOE), local universities, and stakeholders to study the feasibility and investment pathways of reaching these goals, along with implications for jobs, electricity rates, the environment, and environmental justice. The charge led them to the experts at DOE's National Renewable Energy Laboratory (NREL).

Ambitious Clean-Energy Goals Require Ambitious Analysis

Even in LA's sunny sprawl, achieving a 100% renewable power supply is not as simple as building lots of solar panels. LADWP's power system is unique, so navigating possible paths forward presented an analytical undertaking of unprecedented scale and complexity.

So, in 2017, LADWP sought out NREL—the nation's only federal laboratory dedicated to renewable energy research, with a bold vision for transforming the energy system through science—to lead LA100: the Los Angeles 100% Renewable Energy Study.

"LA100 is one of NREL’s most momentous achievements in fulfilling our mission to transfer knowledge and innovations to address the nation's energy and environmental goals," said NREL Director Dr. Martin Keller. "The study offers invaluable insight into how the United States can achieve national-scale goals for a 100% carbon-free power sector."

"LA100 is a first-of-its-kind objective, rigorous, highly detailed, and science-based study to analyze potential pathways the LA community can take to achieve a 100% clean energy future," said Dr. Jaquelin Cochran, manager of NREL's grid systems analysis group and principal investigator of the LA100 study. "It taps into and builds on NREL's decades of experience studying high-renewable power systems at a variety of scales, from our foundational Renewable Electricity Futures Study to the Eastern Renewable Generation Integration Study, and beyond—while leveraging input from a diverse set of stakeholders."

Modeling Power Systems in Unprecedented Detail

NREL offered uniquely technology-neutral, holistic, and best-in-class capabilities to help Los Angeles navigate its clean energy transition—and joined forces with partners from the University of Southern California, Colorado State University, and Kearns & West to tap into additional expertise.

Leveraging the power of NREL's Eagle supercomputer, LA100 tapped into diverse capabilities across NREL's research programs, including detailed electricity demand modeling, power system investments and operations analysis, economic impact analysis, distribution grid modeling, and life-cycle greenhouse gas (GHG) emissions analysis, among others.

There is no single model that can perform all the analysis required for the LA100 study's large temporal, geographic, and sectoral scope. NREL analysts developed a new approach, with multiple steps and feedback loops—and more than a dozen individual tools or models of various types, including NREL's Distributed Generation Market Demand model, Resource Planning Model, and Renewable Energy Potential geospatial modeling tool.

"We had to push our existing tool sets to new levels of sophistication, as there has never been a 100% renewable energy study of a U.S. utility system the size of LADWP that considers all of these elements," said Dr. Paul Denholm, NREL principal analyst and technical lead for the LA100 study.

The results illuminate possible pathways to achieve a 100% renewable electricity supply while electrifying buildings and vehicles—and, importantly, maintaining LADWP's current high degree of reliability.

"Keeping the lights on was a foundational part of this study, as we recognize the critical role of a reliable power grid, especially in a future with more electrified consumer products, like cars," Denholm said. "A 100% renewable grid cannot compromise on reliability—particularly when electricity is playing a greater role in heating, cooking, and transportation. So our study uniquely examined the impact of climate change on demand for electricity, and the vulnerability of the grid to increased occurrence of climate-change-driven natural disasters that might shut down parts of the transmission networks."

Results also highlight economic and environmental impacts and show opportunities for disadvantaged communities to be a part of the solution. This map does not show results but highlights that approximately half of LA's census tracts are designated as disadvantaged communities.

"The study provides a deeper understanding of the challenges and trade-offs in achieving a 100% renewable power grid, as opposed to identifying specific costs, technologies, or project sites," Cochran said. "We know that a renewable grid can be a reliable grid, and that science can equip the community to make informed decisions about which pathways to a renewable, reliable grid best reflect their values."

And LA100 was not just about running models and analyzing data.

Every step of the research was guided by the LA100 Advisory Group, which was established in 2017 to help inform the study's scope and ensure it answered the questions that matter most to the community. The Advisory Group comprised local neighborhood councils, industry, key customers, academia, city government, and more—so it reflected the distinct perspectives and feedback necessary for an economic and equitable local energy transition in LA. Quarterly meetings with the Advisory Group tailored the research to constituents' needs and concerns—pioneering a more holistic approach to energy analysis that centers the community in the conversation.

Possible Pathways to 100%: The LA100 Scenarios

NREL worked with the LA100 Advisory Group to frame the sets of questions addressed in the study, including:

• As more Angelenos adopt energy technologies like electric vehicles and air conditioning, how might that change total demand for electricity throughout LA?
• What could LA's future grid look like? Does reaching 100% mean big changes locally—like building new transmission lines or power plants?
• How can LA make sure that the new system is reliable under extreme events like fires and heat waves?
• What about impacts on jobs, the local economy, air quality, public health, and environmental justice?
• And what might all of this cost?

"To help address these questions, we design scenarios that help us explore different options for how LA might achieve its clean energy future," Denholm said. "Each scenario has the same end goal—100% renewable energy—but how the goal is achieved varies across the scenarios."

The scenarios vary in terms of the speed of the energy transition—whether LA reaches its clean energy target in 2045 per the City Council motions, or a decade sooner—along with different assumptions about the definition of 100% renewable energy, which technologies can be used, how many customers adopt rooftop solar systems, and LADWP's ability to build new transmission lines.

Projections for future customer electricity demand—moderate, high, and stress—were applied to the scenarios to help evaluate how customer choices influence the evolution of the power system. For example, how could LA's overall demand for electricity change if customers make their windows more efficient, switch to electric appliances, or buy electric cars?

"It's important to remember that scenarios are not prescriptions or predictions—LADWP will not choose one scenario as its marching orders," Cochran said. "Instead, the scenarios help illuminate how making different decisions could impact LA's future in a variety of ways—from costs, to environmental concerns, to the local economy."

What NREL Found

Looking across the study scenarios, the LA100 analysis reveals key insights about what a high-renewable-energy future could look like in LA—and beyond.

1. On the road to achieving 100% renewables by 2045, all LA100 scenarios include significant deployment of renewable and zero-carbon energy by 2035, accounting for 84%–100% of energy and a decline of 76%–100% GHG emissions from power plant operations in 2035 compared to 2020, depending on the scenario. Each of the scenarios builds new wind, solar, batteries, and transmission, coupled with operational practices that make more efficient use of these investments.
   
   
2. By 2045, electricity demand (both annual consumption and peak demand) is likely to grow. High levels of energy efficiency can offset this growth in the buildings sector due to a hotter climate, population growth, and electrification. It is the electrification of the transportation sector that primarily propels overall growth in electricity demand.
   
   
3. Also by 2045, with the incentives evaluated in the study, customers are likely to drive significant growth in rooftop solar: 3,000–4,000 megawatts (MW), including up to a third of customers in existing single-family homes. LADWP might also deploy an additional 300–1,000 MW of non-rooftop solar in the Los Angeles Basin. The distribution grid can manage this growth in local solar—along with the projected growth in electricity demand. While almost all parts of the distribution grid will need some upgrades, the LA100 study estimates that, after correcting deferred maintenance on the existing system, a modest number of equipment upgrades would be sufficient to manage growth in demand and local solar. These distribution upgrade costs represent a small fraction of the total cost of the clean energy transition.
   
   
4. Electrification of vehicles and buildings leads to substantial improvements in air quality and associated benefits to public health—widespread across both disadvantaged and non-disadvantaged communities. LA100's results indicate that realizing these health benefits is principally a matter of achieving high energy efficiency and electrification, independent of any particular renewable energy pathway for the power sector.
   
   
5. Also regardless of the pathway, economic impacts to the city of the 100% renewable energy transition are projected to be small relative to the overall size of LA's economy—so while the transition could create thousands of clean energy jobs annually, the clean energy investments alone are not anticipated to notably impact LA’s economy overall.

Diving deeper, the LA100 modeling results show several key trends across all the scenarios studied.

The analysis also revealed several differences between the scenarios in terms of potential costs and benefits.

Comparison of scenarios across select metrics analyzed in LA100

How Other Communities Can Follow LA's Lead

Many other deep-decarbonization and high-renewable-energy studies identify a significant role for solar, wind, and batteries to get most of the way to a 100% renewable future. The LA100 study's findings are consistent—and emphasize that cities across the nation can get started now (through renewable procurement, permitting, siting, and workforce training) while they work through longer-term, location-specific options for the final 10%–20% of the solution.

"Regardless of location, undertaking a power system transition of this scale benefits from complex analysis to provide deep insights for electrification, clean mobility, and power-sector decarbonization, coupled with implications for environmental justice, air quality, and economics," Cochran said. "To that end, the LA100 study charts a methodology that can be used to replicate, build upon, and scale up this type of analysis for other questions and jurisdictions."

NREL's new Accelerating Clean Energy (ACE) initiative aims to help accomplish just that by turning local clean-energy movements into national momentum. ACE brings together key components—technology and technology integration expertise, local community experience, and infrastructure investors—to provide insights, data-driven action plans, and implementation support for achieving local energy initiatives.

ACE builds on the accomplishments of jurisdictions that have tapped into NREL's objective, cross-sectoral experience and analysis to inform key decisions—allowing more of them to tap into LA100-level capabilities to reach their goals.

Get the Full Findings

Read the LA100 executive summary to explore more high-level conclusions from NREL's extensive modeling, research, and stakeholder engagement.

Dig into the study findings on the LA100 website, which includes options to view results by scenario or topic, along with an interactive data viewer. It also includes links to download each chapter of the full report, which contain additional detail, including a complete list of study assumptions and data sources.