Ukraine’s power grid reached a major milestone this week, resuming electricity exports to Europe following months of missile and drone attacks by Russia.
From Oct. 2022 to Feb. 2023 Russia launched almost 200 missiles and 46 drones at the nation’s power grid, according to Volodymyr Kudrytskyi, CEO of Ukraine's national power company and transmission operator, Ukrenergo.
Kudrytskyi on Tuesday remotely addressed the MIT Energy Forum. During those four months, he said Ukraine lost approximately 10 GW of generation and 43% of its high voltage transmission network was destroyed. The operator was forced to impose rolling blackouts, keeping up to 12 million people without power at any given time.
“There was no large thermal or hydro power plant in Ukraine that was not either damaged or destroyed,” Kudrytskyi said.
Despite the destruction, the country on Tuesday resumed energy exports to Moldova and is expected to begin exporting to Poland on Wednesday. How did the embattled nation’s electric grid survive the Russian attacks, and are there lessons for grid operators in the United States?
“When we finish this war, we will be happy to share our know-how with different countries,” Kudrytskyi said.
Preparing for the invasion
Russia invaded Ukraine on Feb. 24, 2022, but preparations had been in the works for years to separate the two nation’s electric grids, Kudrytskyi said.
Efforts to synchronize Ukraine's grid with Europe's began in 2017, and there was about a year of more work needed for the transition when Russia invaded. Those efforts were accelerated and Ukraine connected to the EU grid in March 2022, allowing the country to maintain service to some customers even as Russian attacks disabled other parts of its system.
Also important, ahead of the invasion the grid operator built up a supply of replacement equipment and “secretly prepared a reserve control room two weeks before the invasion,” Kudrytskyi said.
Anticipating the invasion, the grid operator “worked out, together with distribution system operators, emergency schemes for power to be supplied to every region of Ukraine. We imagined different scenarios of disconnections of different power lines and shelling of different substations, to model how we would deliver power to a specific region in a situation when some transmission elements would be off,” he said.
Sandbags were used to shore up critical substations, he said.
“We had to cover the most critical elements of our substations with engineering defenses,” he said, including autotransformers, relay protection equipment and other assets.
Despite physical defenses, Russian strikes damaged or destroyed scores of substations and power plants, forcing the grid operator to improvise.
“We invented a technique that allowed us to secure and preserve the system balance even in the course of these attacks,” Kudrytskyi said. Experts say this could include islanding procedures that prevent a grid collapse.
Last November, Russian attacks successfully destabilized the Ukranian grid, disconnecting it from the EU. In the wake of that attack, the grid operator developed a procedure “that allows us to maintain the balance of the power grid and prevents it from falling apart,” he said.
The technique “proved to be very efficient,” Kudrytskyi said, though he declined to elaborate. “We survived probably eight or nine attacks after November, and there were no instances when our system was unstable,” he said.
“I suspect they have developed islanding procedures where the grid can be (or has been) separated into a number of independent islands,” Kevin Perry, formerly the director of critical infrastructure protection at Southwest Power Pool, said in an email.
Perry said the key to islanding a portion of the grid is to have sufficient generation to meet the load in each segment, with load shedding that maintains the balance. “Each island, separated from the rest of the grid, cannot influence what happens outside of the island, hence any disruption will be contained and limited to just the affected island,” he said.
Ukraine’s grid workers also had to adapt, said Kudrytskyi, with a goal of restoring power three to four times as fast as in the past.
If a transformer might have taken two to three months to install before the invasion, “we managed to do it sometimes in one week, sometimes in three, four days, depending on the scale of destruction,” Kudrytskyi said. Ukrenergo had hundreds of people working in frontline regions with a dedicated stock of materials, and working closely with regional power administrations and distribution system operators, he said.
Sometime in February the Russians “seemed to exhaust their heavy missile fleet” that had been targeting Ukraine’s energy infrastructure, said Kudrytskyi, “And the good news is that this infrastructure, this power system, survived and is still operating.”
Kudrytskyi is optimistic about the future of Ukraine’s power system. The grid modernization work, even for a nation under siege, looks similar to other parts of the world.
”We have plans to phase out coal-fired generation in the next five to 10 years, and to replace it with clean, sustainable, but also efficient sources of power,” he said. “And I'm sure that after our victory, we will not be alone in this process.”
Ukraine will also lean on its nuclear fleet to reduce carbon emissions, he said.
From a security perspective, “we are now finalizing the design of protected substations,” Kudrytskyi said, and could be the first in the world to implement new defenses.
Perry said he is “intrigued” by Ukrenergo claims to have devised a way to protect substations from physical attacks, including missiles. “I am envisioning them enclosing the equipment in some sort of blast-hardened structure, or burying the equipment underground,” he said. “Either way, they will have to overcome the heat dissipation challenges.”
It remains unclear whether any new techniques would be applicable in North America, he said. The U.S. has faced a rise in physical attacks on its energy infrastructure, and federal regulators are mulling tighter security rules.
There were almost 1,700 physical grid security incidents reported in 2022, according to the North American Electric Reliability Corp., up 10.5% from 2021, though only a fraction cause outages or other grid impacts. Most of the incidents are categorized as gunfire, ballistic damage, intrusion or tampering and vandalism.
Kudrytskyi stressed the importance of stockpiling equipment, particularly high voltage transformers.
In North America, there is an industry-led initiative to stockpile long-lead-time transmission equipment led by Grid Assurance. In December, officials said the time to procure equipment has grown to 20 to 39 months from 16 to 20 months the year before. Meanwhile costs have risen 20% to 50%.
”We did not manage to find a lot” of high voltage transformers, Kudrytskyi said. “It’s obvious no one is ready. ... Transmission system operators all around the world should think about creating a strategic stock of this equipment, autotransforms, relay protection terminals [and] some other critical elements of the substations which will possibly be targets.”