Power grid operators need flexible and dispatchable resources, especially when grids are under extreme stress or emergency conditions. The worse the conditions, the greater the need for flexible resources. 

There’s no energy resource that’s more flexible or dispatchable than batteries. They can respond in sub-seconds and fulfill a variety of grid needs. 

So why on earth is ERCOT trying to slow down battery deployment?

Last month, the ERCOT Board unanimously approved a protocol revision request (ERCOT’s version of a rule change) requiring batteries to maintain a state of charge at all times. Batteries, of course, are meant to be depleted and recharged; ERCOT’s rule would force them to always have more juice, even in dangerous conditions — times when Texans desperately need it.

“ERCOT is trying to make batteries look like and act like coal plants,” Commissioner Glotfelty wrote in a memo that injected some common sense into the discussions of ERCOT’s protocol revision request (known as NPRR 1186). 

Commissioner Glotfelty suggested to ERCOT CEO Pablo Vegas back in August that the proposal would increase costs for consumers and create reliability problems; he suggested ERCOT to go “back to the drawing board” on the proposal and to “not pass it at the next Board meeting.” ERCOT ignored that advice — the politically appointed board unanimously passed a protocol revision that somewhat eased the heavy handed regulation of batteries but would still force batteries to hoard electricity when Texans need it. 

And so, three months later, the PUC was again left to express its displeasure with a regulation that would discourage investment in a dispatchable power source that Texas desperately needs…

It was a white knuckle night in the ERCOT control room. On Thursday, August 17th, reserves on the ERCOT grid dropped below 3,000 megawatts — less than 4% of the total system demand at that point — and got close to the 2,300 megawatts that would require ERCOT to declare emergency conditions.

The same night, industrial-size batteries put 1,800 megawatts of power — more than double the previous record — onto the grid when reserves reached their lowest point. Without batteries, ERCOT probably would’ve declared an emergency that night. We were very close to the edge.

The same thing happened four times over the next week or so: storage put between 1,100 and 1,325 megawatts of power onto the grid between 7:15 - 8:30 p.m., right as reserves reached their nadir on August 20, 23, 24, 25, and 29 — all days when ERCOT issued conservation calls.

These hot summer nights show the vital role that storage should play on the grid, filling the gaps in those moments when demand threatens to overtake supply. The amount of storage on the grid has mushroomed in recent years — and much, much more is on the way.

So is ERCOT opposing its expansion in a key ancillary service market?