Leaders of Mexico’s state power utility Comisión Federal de Electricidad (CFE) on Tuesday blamed renewable energy and a brush fire for a massive Dec. 28 power outage that took 8,696 MW of electricity offline, causing about one-third of the country to lose power. 

Bartlett

Spokesman Luis Bravo Navarro said that while it’s normal for small sections of transmission lines to fail due to force majeure causes, the blackout in Mexico was more widespread due to an “excess of intermittent generation.”

Bravo said that Mexico’s intermittent generation capacity, presumably a reference to wind and solar farms, is expected to double in the near future, based on the projects that have been approved by the Comisión Reguladora de Energía (CRE), which oversees permitting and regulations in the power sector. He claimed this will increase reliability risks across the national system. 

Non-hydropower renewables currently account for 4% of Mexico’s primary energy supply, per BP plc’s 2020 Statistical Review of Energy, while natural gas supplies 42%.

System operator Centro Nacional de Control de Energía (Cenace), Bravo said, “is obligated by law to limit in each node the maximum capacity to generate, to ensure reliability. This will mean for private generators reducing their annual production.”

Gadex consultancy co-founder Eduardo Prud’homme told NGI’s Mexico GPI there likely is no legal basis for this assertion.

“One problem could be that there is a lack of ancillary services,” Prud’homme said, explaining that Cenace has stopped bidding processes to procure these services. 

Ancillary services “help balance the transmission system as it moves electricity from generating sources to retail customers,” according to the PJM regional transmission organization in the United States.

CFE General Director Manuel Bartlett Díaz has been among the loudest voices in President Andrés Manuel López Obrador’s government against the 2013-2014 constitutional energy reform, which opened the door for private sector companies to compete directly with CFE in the power generation segment.

López Obrador has suspended auctions for new generation and transmission capacity in order to fulfill his mandate of “rescuing” CFE and national oil company Petróleos Mexicanos (Pemex).

His government, through energy ministry Sener, also has sought to unilaterally modify power sector rules to give priority to CFE in the dispatch order, even if private generators are able to produce power more cheaply.

Bravo went on to say that the Pidiregas financing scheme, a public-private financing mechanism for energy infrastructure projects that predates the energy reform, “has left CFE indebted for $50 billion” for investments in power plants, transmission lines, substations and natural gas pipelines.

He said that, “in Mexico, neither the federal government, large industry, small and medium industry, the commercial sector, nor domestic users, can continue subsidizing private investors.”

In addition to being Mexico’s largest power generator, CFE holds monopoly positions in the transmission and distribution segments.

Noé Peña Silva, director of CFE’s transmission unit, said that smoke from a brush fire in Tamaulipas state ionized the air, generating an electrical arc that diverted electricity from the transmission system to the ground. 

Carlos Morales Mar, head of operations for CFE, said that renewable generators were unable to respond to “oscillation” in the system as a result. 

CFE said that its power stations, including combined-cycle power plants, conventional thermal power stations, hydroelectric dams and geothermal plants, stabilized the system following the outage.

Bartlett dismissed accusations that CFE has failed to invest sufficiently in strengthening its transmission grid, instead blaming the “indiscriminate” awarding of renewable energy projects for the outage.

Prud’homme said that under normal circumstances, CRE would commission an independent investigation in order to determine the cause of the power outage and if necessary, levy a fine on the transmission operator, in this case CFE. 

However, he said, this is unlikely to happen due to the politicization of CRE under López Obrador as a tool to protect the interests of CFE and Pemex.