(Bloomberg) -- Texas lawmakers are grilling power executives, regulators and others for a second day about why the state’s energy system failed last week. So far the hearings have led to plenty of finger-pointing but few clear answers about how to prevent a similar crisis in the future.Executives from Calpine Corp., Vistra Corp. and NRG Energy Inc. blamed natural gas-supply shortages, grid disturbances and a lack of communication from the grid operator known as Ercot. Ercot, meanwhile, said it simply followed the rules and direction set by the state’s Public Utility Commission which, in turn, said it lacked authority to tell Ercot what to do.“This is the largest trainwreck in the history of deregulated electricity,” Republican Senator Brandon Creighton said Thursday.Executives from the electricity retailer Griddy Energy LLC will face questions about customers who have received bills for thousands of dollars. The company’s unique business model sells power based on the wholesale market prices, which skyrocketed when supplies on the grid fell short. And shale driller Diamondback Energy Inc. will be asked about how production and transportation were affected by the storm.The historic outage left more than four million homes and businesses without heat, light and water during a deep winter freeze, causing as much as $129 billion in economic losses. Some electricity providers wracked up huge losses, fueling a possible credit crisis, oil and gas producers saw their output halted and the impact to individual companies is only starting to emerge. Dozens of people died.Highlights From Day One:Texas’s energy regulator said power outages, not ice, were the main reason oil and gas production halted during crisis.Calpine, Vistra and NRG said natural gas shortages affected their ability to operate. The companies also said plants were forced offline after the flow of electricity on the grid -- called frequency -- plunged. That contradicts the version of events presented by Ercot.The CEOs of Vistra and NRG said that their companies wouldn’t pass on to customers the high energy prices from the event.Ercot anticipated that blackouts were possible four to five days beforehand. Calpine’s CEO, however, said it wasn’t warned that a grid emergency was possible.All times Eastern.Power Retailers Complain of Exorbitant Energy Charges (2:08 p.m.)Tom Hancock, the chief executive officer of utility Garland Power & Light, told lawmakers the cost of their ancillary services last week equaled 28 years of ancillary service costs based on last year’s total.Ancillary services help the grid operator maintain reliability on the system, including by infusing the grid with quick bursts of energy that stabilize the flow of electricity.Several retail electricity providers, including Young Energy LLC and Spark Energy Inc., Texas have disputed the costs of those services during last week’s energy crisis, and are seeking emergency relief from the Public Utility Commission. Freepoint Commodities LLC has also appealed to the commission, saying they intend to challenge Ercot’s ancillary service charges and are concerned the grid operator lacks the liquidity to return any successfully disputed payments.Ercot Loses 7th Board Member as Hearings Continue (1:25 p.m.):Texas’s grid operator Ercot lost a seventh board member Friday with the resignation of Clifton Karnei, who represented electric cooperatives. An Ercot spokesperson confirmed the resignation.The board’s chair and vice chair were among other members who resigned earlier this week in the wake of the energy crisis.Utility Says Ercot Hasn’t Paid It in Three Days (12:59 p.m.)The Lower Colorado River Authority, a public utility, has waited for payment from Texas’s grid operator for three days, according to President Phil Wilson. The power provider usually gets paid everyday, he said.The grid operator known as Ercot is currently trying to manage defaults by certain market participants in the wake of the crisis to ensure that generators are paid, officials said during a board meeting Wednesday.Wilson said high energy prices and generation issues during the grid emergency also affected the company’s revenues. “We lost money at the end of the day,” he said, adding that he hopes the utility will end the year “relatively unscathed.”Regulator Didn’t Know Gas Could be Classified ‘Critical Infrastructure’ (11:00 a.m.)The head of Texas’s energy regulator said she, in the lead-up to the blackouts, didn’t know natural gas facilities could be considered “critical infrastructure” spared from outages. “I didn’t know that was an opportunity,” Texas Railroad Commission Chair Christi Craddick told lawmakers during a house hearing Friday.Oncor Chief Executive Officer Allen Nye, speaking in a simultaneous senate hearing, said only 35 gas facilities were on his critical infrastructure list going into the event. The power distributor, which was responsible for implementing the blackouts ordered by the grid operator, added 168 facilities after receiving calls from the Railroad Commission and gas suppliers.‘Enormous’ Financial Obligations May Lead to Power Bankruptcies (12 a.m.)With sky-high wholesale power prices in place for days, power retailers and cooperatives in Texas racked up an “enormous amount of obligations” to generators, the state’s main grid operator said.Combined payments owed to generators hit $10 billion one day during the blackouts and $9.5 billion another, Ercot Chief Executive Officer Bill Magness said in a hearing at the state House of Representatives. Participants and cooperatives that owe those bills may have trouble paying and some may file for bankruptcy, he said.Another problem on the horizon is if some retailers aren’t able to pay, it’s unclear how the debt will be paid to the generators, Magness said. The agency is currently trying to determine how many won’t be able to pay so it can come up with an answer, he said.“We’re running into a big issue on the financial side because magnitude of money owed is enormous,” Magness said. “If a generator doesn’t get paid, we may lose generation on system, then that becomes an operational problem.”READ ALSO: Texas Cities Fret as Power Bills Mount in Wake of BlackoutsTexas’ $9,000 Power Price Cap ‘Didn’t Work,’ Regulator Says (11 p.m.)Texas’ $9,000-per-megawatt-hour maximum power price didn’t work during recent blackouts, Public Utility Commission Chairwoman DeAnn Walker said during a state House of Representatives hearing.The rate was set to entice generators to produce more power or for customers to consume less when reserves get low, and it has worked well during summer peaks, mostly because big industrial customers don’t want to pay the stiff bill, Walker said.During the power outages, the PUC ordered Ercot to keep the price at the cap to try to maximize generation, and prices were at or above that level for seven straight days, yet millions were still in the dark for days.“It didn’t work, and we have to fix that,” Walker said. “It’s a very complicated issue and I don’t have any ideas right now, but we need to work together to figure that out.”For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.