In their ongo­ing inves­ti­ga­tion into what caused California’s rolling black­outs in August, the state’s elec­tri­cal grid oper­a­tor and util­ity reg­u­la­tors have focused pri­mar­ily on struc­tural issues like cli­mate change-​​driven heat and the tran­si­tion to renew­able energy sources.

But two months after the his­toric event, offi­cials still haven’t come up with a defin­i­tive set of answers.

“We’re still try­ing to do a lot of work to under­stand the data we have,” Del­phine Hou, direc­tor of reg­u­la­tory affairs for the Cal­i­for­nia Inde­pen­dent Sys­tem Oper­a­tor (CAISO), said dur­ing a pub­lic stakeholder’s call last week.

The rolling black­outs, the state’s first in almost two decades, thrust more than 800,000 Cal­i­for­ni­ans into the dark dur­ing an intense heat­wave on Aug. 14 and 15, when oper­a­tors directed util­i­ties to shut down power to pre­vent the grid from being over­whelmed. But some energy experts say key ques­tions about the sequence of events that led to the black­outs have gone unan­swered or unacknowledged.

For exam­ple, CAISO’s pub­lic sum­maries — includ­ing a 108-​​page Oct. 6 pre­lim­i­nary analy­sis com­piled jointly with the state’s Pub­lic Util­i­ties Com­mis­sion and Energy Com­mis­sion — makes no men­tion of an out­age that occurred at Ormond Beach Unit 1 in Oxnard, a nat­ural gas plant with a whop­ping 741-​​megawatt gen­er­at­ing capac­ity. The plant went offline for main­te­nance just 8 min­utes before CAISO declared a Stage 3 emer­gency on Aug. 14, notes energy expert Bill Pow­ers, the head of Pow­ers Engi­neer­ing in San Diego. He says the record of that inci­dent is buried in a spread­sheet.

Instead, CAISO’s time­line focuses on a plant in Blythe, a city in River­side County, where an out­age that same after­noon had been resolved for more than 40 min­utes by the time CAISO called for rolling blackouts.

“The ISO’s mes­sag­ing in the imme­di­ate wake of these black­outs was non­trans­par­ent and much of it appears to be incor­rect,” Pow­ers said. “Ormond Beach is the ele­phant in the room. Why is that ele­phant invis­i­ble? Why are we talk­ing about Blythe Energy Cen­ter which had noth­ing to do with the blackout?”

There are also lin­ger­ing ques­tions about CAISO’s account­ing of events on Aug. 15, when the liai­son between CAISO and Panoche Energy Cen­ter, a power plant near Fresno, issued what CAISO calls an “erro­neous dispatch.”

That liai­son, known as a sched­ul­ing coor­di­na­tor, told the power plant to ramp down out­put as demand was peak­ing. A CAISO out­age report issued on Sept. 11 omits that PG&E was the sched­ul­ing coor­di­na­tor, and that its per­son­nel made the erro­neous dispatch.

The San Fran­cisco Chron­i­cle and KQED reported last month on PG&E’s role, which is also left out of the Oct. 6 analysis.

PG&E’s action — which resulted in 248 megawatts of power com­ing off the state’s grid — took place 3 min­utes before CAISO declared a Stage 2 emer­gency, denot­ing it was no longer able to pro­vide expected energy require­ments. The Stage 3 dec­la­ra­tion — sig­nal­ing that shut­offs were immi­nent — fol­lowed 12 min­utes later.

PG&E says the ramp-​​down lasted less than half an hour, and that it cor­rected the error imme­di­ately upon iden­ti­fy­ing it.

“PG&E does not know if the error resulted in rotat­ing out­ages,” said com­pany spokesman James Noonan.

The util­ity did not respond to KQED’s ques­tions about whether it took action to pre­vent sim­i­lar inci­dents from hap­pen­ing again, or if any com­pany per­son­nel were disciplined.

“Peo­ple make mis­takes. That’s why well-​​run orga­ni­za­tions have checks and bal­ances to dis­cover those mis­takes before they cause harm,” said Steve Weiss­man, a lec­turer at the UC Berke­ley Gold­man School of Pub­lic Policy.

“In the past, PG&E has run into prob­lems because it has not tended to main­tain those kinds of qual­ity con­trol processes,” he said. “If PG&E had sys­tems in place to catch those mis­takes, why did they miss this one?”

For the last sev­eral weeks, CAISO has declined KQED’s requests to review record­ings of ver­bal com­mu­ni­ca­tions between PG&E and CAISO, which could shed light on whether CAISO was aware of the error in real time.

In a state­ment, PG&E said the util­ity informed CAISO of the full details of the inci­dent three days later.

The issue of how quickly CAISO can see — and react to — what the state’s many power resources are pro­duc­ing, mat­ters sig­nif­i­cantly as Cal­i­for­nia tran­si­tions away from fos­sil fuels to more renew­able energy sources, accord­ing to Daniel Kam­men, direc­tor of UC Berkeley’s Renew­able and Appro­pri­ate Energy Lab­o­ra­tory (RAEL).

“We need a sys­tem with bet­ter data feed­back and more real-​​time updates so CAISO can make the right deci­sions,” Kam­men said. “We need to know pre­cisely what’s hap­pen­ing. Tech­nol­ogy makes that very pos­si­ble today.”

While Kam­men hasn’t stud­ied what hap­pened at the Ormond Beach plant, he says the tim­ing of the rolling black­outs looks “com­pletely tied” to that lack of capac­ity. In his view, energy stor­age is crit­i­cal to ensur­ing reli­a­bil­ity dur­ing the grow­ing shift to renewables.

“They sim­ply don’t know what resources they have avail­able to them. We’ve had 10 years of plan­ning to try and fix that,” Kam­men added. “That’s CAISO’s job. If they don’t have the capac­ity, they should ask the governor’s office and the [pub­lic util­i­ties com­mis­sion] for what­ever they need to get there.”

CAISO offi­cials have high­lighted prob­lems with the com­plex energy mar­ket it oper­ates. In that mar­ket, much of the state’s power is booked just a day in advance. A prac­tice called “con­ver­gence bid­ding” — which involves trad­ing vir­tual power — is intended to smooth the gap between the day-​​ahead and real-​​time markets.

“We were not set up cor­rectly,” Hou said on last week’s call. “So the real-​​time mar­ket had to work extra hard to untan­gle what was set up a day ahead.”

Accord­ing to the Oct. 6 analy­sis of the black­outs, sched­ul­ing coor­di­na­tors “under-​​scheduled” or didn’t line up enough power ahead of time, mean­ing the mar­ket didn’t “reflect the actual need on the sys­tem.” That, in turn, sig­naled that “more [energy] exports were ulti­mately supportable.”

In other words, says for­mer CPUC Pres­i­dent Loretta Lynch, Cal­i­for­nia was export­ing power up until CAISO called for rolling black­outs. “They were serv­ing the energy traders over the Cal­i­for­nia econ­omy,” Lynch said.

CAISO con­tends that the region-​​wide August heat storm made import oppor­tu­ni­ties scarce. On last week’s call, when asked why it did not con­sider cur­tail­ing exports dur­ing the two-​​day black­out, an offi­cial asked for patience.

“We need to put into per­spec­tive how the tim­ing of this hap­pened. We started tak­ing action as we unrav­eled these lay­ers,” said Guillermo Bautista Alderete, CAISO’s direc­tor of mar­ket analy­sis and fore­cast­ing. “We have to first ana­lyze what hap­pened. Then under­stand what hap­pened. Then look at our next oppor­tu­nity to effec­tu­ate change.”

In the last week, CAISO has announced the depar­tures of two top exec­u­tives: Vice Pres­i­dent of Oper­a­tions Eric Schmitt and Vice Pres­i­dent of Tech­nol­ogy Petar Ris­tanovic. A CAISO spokesper­son said both men had been con­sid­er­ing retire­ment for some time, and that their deci­sions were unre­lated to this summer’s outages.

In the com­ing weeks, experts will be look­ing for signs of a par­a­digm shift in how the state ensures it can pro­vide reli­able power to Californians.

“How do we keep the lights on in a world in which a grow­ing share of gen­er­a­tion capac­ity sup­plies power when the sun is shin­ing and the wind is blow­ing?” asked Frank Wolak, an eco­nom­ics pro­fes­sor at Stan­ford, who chaired CAISO’s Mar­ket Sur­veil­lance Com­mit­tee from 1998–2011.