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.