Why doesn’t Texas have a Capacity Market?

April 10, 2019

When the Electric Reliability Council of Texas (ERCOT) established Texas’ deregulated energy market in 1999, it had several very Texan ideals in mind.

For starters, the market’s architects sought good old-fashioned economic competition to keep electricity prices stable and the state’s grid reliable.

They also settled on another battle-tested Texan value concerning its energy market: They wanted to be completely different from New York…and California, New England, and PJM for that matter.

And so it came to be that Texas would establish an energy-only market without a forward capacity market. In doing so, ERCOT became the only deregulated energy market in the US that is NOT overseen by the Federal Energy Regulatory Commission (FERC).

In the two-plus decades since ERCOT’s formation, naysayers in and out of Texas have been watching the Lone Star State with skeptical eyes, waiting for the perfect storm when a lack of forward-procured capacity proves fatal to grid stability.

Every time the reckoning seems imminent (as it did in the Summer of 2018) the ERCOT market holds strong, bending at times but never breaking. Now, many former naysayers around the US are wondering if perhaps instead of messing with Texas, other deregulated energy markets should be learning from the Lone Star State.

That Texas doesn’t have a forward capacity market is one of the market’s signature design features.

Consider a market like the Pennsylvania-Jersey-Maryland (PJM) Interconnection. To keep its grid reliable, PJM maintains a forward capacity market (the largest in the world) whereby the capacity needed to meet peak-demand is procured three years in advance of its delivery day.

Using this model, PJM procured a comfortable reserve of about 21% above its reserve target in its latest capacity auction. The onus of paying for this surplus of capacity falls to ratepayers in the market, who pay for PJM’s reserve margin with higher capacity prices/demand charges.   

The ERCOT market, in contrast, aims to keep costs incurred by its ratepayers at a minimum by avoiding what they see as an unnecessary surplus of capacity.  

Instead of a capacity market, ERCOT maintains a capacity reserve margin, calculated by subtracting the projected peak demand on the grid from the total capacity generation available in Texas.

ERCOT’s target reserve margin hovers around 13.75%, lower than PJM’s 15.8%–considerably cheaper for Texan ratepayers, too.  

Back to the original question of why doesn’t ERCOT have a capacity market. The answer is simple and decidedly Texan: Economics. Economics. Economics. (and a little desire to be different).

The Summer of 2018: ERCOT’s Proving Ground

For years, skeptics have watched the ERCOT grid, wondering when the right set of circumstances would finally expose Texas’s lack of capacity market for its inability to maintain grid reliability.

Last summer, it looked like the skeptics would finally have their day.

A shrinking reserve margin, record-setting peak demand, and a near-record heat wave pushed the ERCOT grid to its limits, but the grid held.  

In September 2018, the Public Utility Commission (PUC) of Texas issued a 45-page Review of Summer 2018 ERCOT Performance, officially summarizing how the grid functioned against daunting conditions.

That the lights stayed on in Texas last summer boosts ERCOT’s belief that an energy-only market relying on economic competition as opposed to government mandate can maintain sufficient resources to keep the grid stable and avoid turning to emergency, out-of-market measures.   

Much of the energy industry has taken note, too.

The R Street Institute, a public policy research organization based in Washington D.C., noted “the Texas market is working, as consumers and producers find innovative ways to reduce costs and enhance service quality.”

Demand Side Management to the Rescue

The PUC’s performance review also noted the integral role demand-side and distributed energy resources (DERs) played in keeping ERCOT’s grid reliable during the Summer of 2018. There were no rolling outages or blackouts.   

Despite not experiencing a demand response event during this past summer, ERCOT’s ongoing investment in ancillary services and recent updates on how they are procured and dispatched have paid off.


This post was excerpted from the 2019 State of Demand-Side Energy Management in North America, a market-by-market analysis of the issues and trends the experts at CPower feel organizations like yours need to know to make better decisions about your energy use and spend.

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Published by

Mike Hourihan

Mike Hourihan is market development manager and analyst for the ERCOT and IESO markets. He is a long-time advocate for demand-side resources participation as a reliable low-cost alternative to traditional generation assets. He has extensive experience in analyzing and developing market rules in multiple energy markets across North America.

Mike Hourihan

Mike Hourihan is market development manager and analyst for the ERCOT and IESO markets. He is a long-time advocate for demand-side resources participation as a reliable low-cost alternative to traditional generation assets. He has extensive experience in analyzing and developing market rules in multiple energy markets across North America.