Tennessee Valley Authority executives said the rolling blackouts it ordered local power companies and industrial electric users to implement early Saturday helped stave off broader issues and that the federal agency "fell short" in its effort not to interrupt power.

TVA CEO Jeff Lyash said the federal agency could have communicated better with its 153 local power companies and it is already analyzing why equipment failed after it invested hundreds of millions into reliability measures for extreme cold.

"It is TVA's very objective and that of our local power companies, each and every one of those 153 local power companies, never to interrupt your power. That's what we strive for. And occasionally we fall short of that. And, obviously, we fell short of that, in this case," Lyash said during a conference call with elected officials across its seven-state footprint.

The Commercial Appeal obtained access to the call. Lyash did not take questions from the elected officials on the call. Comments later made by Memphis Light, Gas and Water CEO Doug McGowen during a noon news conference offered a window into how the federal agency's evolving plans forced MLGW to adjust rapidly and turn out the lights for more people than expected.

"It is difficult to make a forecast when you have little notice about initiating the plan and even less notice about changing the plan," McGowen said.

TVA was not alone in instituting rolling blackouts. To its east, Duke Energy, which serves much of the Carolinas, instituted rolling blackouts Saturday as its grid struggled.

Energy Information Administration data showed that TVA imported a considerable amount of energy Friday from the Midcontinent Independent System Operator, a neighboring electric grid. The data lags and so it was not immediately clear what transpired Saturday.

TVA's net generation -- the amount of energy it generates fell about 7,000 megawatts short of demand around midday Friday. TVA was generating about 23,000 megawatts and needed more than 30,000.

CEO says blackouts preserved grid

Lyash said the decision to tell local power companies, including MLGW, to cut off power to up to 10% of its electric load was essential.

"The job that they did made a material difference and helped us preserve the reliability of this system," Lyash said.

He said the federal agency is already analyzing what went wrong.

"I would tell you all as leaders, we have already begun to scope our post-event critical assessment. I will tell you I think communications from TVA to local power companies, to local officials, industrial customers could have been better and there are gaps there," Lyash said.

He said the federal agency would analyze what investments are needed to avoid future problems.

"[TVA COO Don Moul] has already begun the assessment of the equipment and system performance. We have invested hundreds of millions of dollars and hardening this system and preparing it for events like this," Lyash said. "In some cases, the preparation wasn't effective. And so we clearly need to do more. We're going to assess the performance of this system. We're going to identify the investments that need to be made so that if we experience an event like this again, in the future, our assets perform better than they did this time."

TVA first told local power companies to cut 5% of the load, then told them 10%

Lyash acknowledged that the federal agency first told local power companies to cut 5% of their load early Saturday morning and then that went up to 10%. McGowen noted how quickly the situation changed Saturday and his comments perhaps portrayed some of the communication issues Lyash acknowledged.

"TVA had to take very aggressive and very rapid action so they could avoid a much more serious crisis across our area.... All of that happened in a very short period of time despite everyone's best forecast of the weather and best forecast of conditions," McGowen said.

That rapid-fire change in conditions posed issues for local power companies, McGowen said the change from 5% load to 10% load reduction happened in 10 minutes. The first alert went out at 5:06 a.m. and the second at 5:16 a.m.

"It's not an optimum condition but that's how things unfolded," McGowen said.

The need to shed 10% of its load made MLGW deviate from its planned cadence of blackouts, putting more people out of power and having the outages last longer. That prompted anger from MLGW customers, something that McGowen apologized twice for Saturday.

Part of the reason TVA had to shed so much electricity demand is that it had issues with the electricity supply. It lost natural gas plants and at least two coal plants went down. Lyash and Moul, the federal agency's COO, acknowledged there were also issues with third-party contracted plants that are supposed to provide extra supply.

"It created a very challenging situation," Lyash said.

Samuel Hardiman covers Memphis city government and politics for The Commercial Appeal. He can be reached by email at samuel.hardiman@commercialappeal.com or followed on Twitter at @samhardiman.

This article originally appeared on Memphis Commercial Appeal: TVA CEO Jeff Lyash said agency fell short during Tennessee, Memphis blackouts