Distributed Energy Resources

NREL report outlines possible paths for the evolving power sector

Wind farms will likely be the largest source of electricity by 2050 in the U.S., while natural gas-fired power plants will provide the most capacity of all generating resources, according to a report from the National Renewable Energy Laboratory.

The report, "2019 Standard Scenarios Report: A U.S. Electricity Sector Outlook,” aims to capture a range of possible future power systems considering various factors that affect the power sector.

NREL said it expects that policymakers and others can use the annual study to understand key drivers, important implications and decision points that can contribute to more informed investment and policy decisions.

The study examines 36 scenarios that include different levels of demand growth, fuel prices and technology prices as well as other factors.

Under a “mid-case scenario” total generation grows steadily over time, mainly through new natural gas combined cycle power plants, photovoltaic facilities and wind farms, according to NREL, the Department of Energy's primary national laboratory for renewable energy and energy efficiency research and development.

Driven by assumed lifetime retirements, coal and nuclear capacity declines over time, resulting in less generation from those resources, NREL said. In the late 2040s, wind and solar generation increase more rapidly, partly to replace a surge in coal-fired and nuclear plant retirements, according to the research lab.

Under the mid-case scenario, by 2030 renewables produce 28 percent of U.S. power production, fossil-fueled plants produce 57 percent of the electricity and nuclear plants account for 15 percent of power production, according to the report.

By mid-century, power production shares for renewables, fossil-fueled plants and nuclear facilities are 60 percent, 33 percent and 7 percent, respectively.

In the mid-case scenario, the fleet-wide coal capacity factor dips to 50 percent by 2050, down from 54 percent last year, NREL said.

Fleet-wide natural gas combined cycle capacity factors fall slowly as the units provide increasing amounts of flexibility to respond to renewable energy variability, falling to a fleet-wide capacity factor of 34 percent in 2050 from 58 percent last year, according to NREL.

NREL found that the regional distribution of power plants will likely remain unchanged, with the largest generation levels occurring in states with the greatest electricity consumption, such as California, Florida and Texas.

However, proportionally larger future renewable deployment is found in states like Nebraska and New Mexico that have high-quality wind and solar resources or policies supporting high levels of renewables, according to the research lab.

Battery storage could displace a significant amount of natural gas-fired combustion turbines as battery costs continue to decline so that the technology becomes the most common type of “peaker plant” in most scenarios, NREL said.

NREL highlighted three key themes from its report.

First, the research lab found that the modeled revenue received by technologies through delivering grid services changes over time and across scenarios as the grid mix evolves.

In 2030, most technologies get most of their revenue from providing energy, with natural gas combustion turbines being the only exception, NREL said. The research lab found that by 2050, the fraction of revenue from providing energy has declined for all technologies and has largely been displaced by revenue in providing planning reserves.

Second, even at high variable renewable energy penetration levels, resource adequacy requirements are largely supplied by non-variable technologies, according to NREL.

Third, NREL found that regional generation mixes continue to change through 2050, driven mainly by technology costs, state policies and resource quality.

NREL is holding a webinar on January 9 to discuss the report. Additional details on the webinar are available here.