North America’s largest power grid and its stakeholders need to ensure “adequate” electricity supply from thermal power plants, which include natural gas- and coal-fired units, until a substitute is deployed at scale, according to initial results of a study by grid operator PJM Interconnection.

PJM power gen mix

“As the generation mix continues to rapidly evolve in PJM, we must be ready to maintain the reliable, cost-effective delivery of electricity at all times,” said CEO Manu Asthana.

PJM, which serves 65 million people across 13 states and the District of Columbia, said it must work with stakeholders to “ensure that the market structure provides the right incentives to maintain…reliability services” from thermal power generators. 

The conclusion represents one initial finding from the “Energy Transition in PJM: Frameworks for Analysis” paper. PJM said the paper reflects its “five-year strategy…built on three pillars – enabling state and federal decarbonization policies, planning for the grid of the future, and fostering innovation.” 

According to PJM, the grid operator is engaged in a “multiphase, multiyear effort to study the potential impacts of an evolving resource mix, including the acceleration of renewable resources.”

PJM “synthesized the diverse set of state policies within its footprint into three scenarios.” The three scenarios assume varying degrees of annual increases in energy served by renewable generation: 10%, 22% and 50%. The grid operator pointed out the scenarios reveal up to 70% carbon-free generation when combined with nuclear generation.

“Currently, renewables represent approximately 6% of the annual energy, a total of over 40% carbon-free when combined with nuclear’s contribution to the energy mix in 2020,” PJM stated.

80% Natural Gas-Fired Capacity 

The grid operator had 184,396 MW of installed capacity within its electrical territory at the end of 2020, according to PJM. Natural gas-fired capacity made up more than 43% (80,115 MW) of that total. Coal commanded the second-largest share at 27.5% (50,689 MW), followed by nuclear at slightly under 18% (32,640 MW), with oil at about 5% (8,629 MW) and hydro at 4.5% (8,275 MW). Wind, solar, and waste made up more than 2% (4,048 MW combined).

PJM plans to add more than 3,400 MW of gas-fired capacity in 2022. The grid operator’s all-time record for single-day power use was 165,563 MW in 2006.  

In addition to underscoring the need for a market structure that supports ongoing thermal generation reliability, the study highlighted four other “key focus areas for PJM’s stakeholder community” to examine in future study phases, PJM said.

PJM said the additional themes include finding new approaches to correctly calculate generators’ capacity contribution as variable resources expand; elevating the role of operational flexibility to account for variable resource uncertainty; finding opportunities to expand regional transmission and deploy storage and grid-enhancing technologies; and setting appropriate performance, cybersecurity, and reliability standards for distributed energy resources as they penetrate the grid.  

“This study represents an important step in understanding how PJM can best work to facilitate the energy transition and make the grid of the future possible,” said Asthana.