Iberian blackout sheds light on grid fragility
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As Spain, Portugal and the European Commission continue to investigate the blackout that shook the power grid across parts of the Iberian Peninsula, the energy sector is reflecting on the different elements that contributed to the power outage. One not-so-minor element is the grid itself.
Monday’s blackout that affected the power systems of Spain, Portugal, and parts of France left the sector agog.
Now, experts are trying to figure out how it could have been avoided, mitigated or prevented. In large part, it comes down to how the power grid is set up.
Power outage experts have ruled out renewables as the cause, and according to Juliet Phillips, energy campaigner at Berlin-based non-profit Beyond Fossil Fuels, power system failures are overwhelmingly rooted in grid weaknesses.
Said Phillips in a statement: “Grid system operators need to be given a climate mandate to invest and plan for the renewables-based energy system of the future.
“This requires a rapid scale up of energy storage, interconnectors and other sources of flexibility. They need to be empowered to implement these solutions, particularly as we face the prospect of more frequent extreme weather events.”
More on the blackout:
Power being restored to Portugal and Spain as focus turns to cause of outage
Spain and Portugal recover from massive power outage
Interconnections
As mentioned by Phillips, one significant pain point that has come into stark relief from the blackout is the Iberian peninsula’s structural isolation and how interconnection, although providing immense relief, requires more attention.
According to grid tech company VIOTAS in a release, interconnectors facilitate electricity flow across borders to where it is most needed, preventing the forced curtailment of variable renewable power.
The Iberian grid is connected to France via Spain’s 2.8GW electricity interconnector and via interconnection with Morrocco with combined 1.4GW capacity.
The support of this interconnection, as well as the black start ability of hydro power plants, enabled system operators to restore power, but the question remains of how much relief more interconnection may have provided.
Getting interconnectors running, however, is not a simple task.
According to Bruegel, one significant element to this comes down to distributing benefits between countries, meaning these types of projects tend to get delayed or not developed at all. Bruegel cites the Spain-France interconnector, which took six years to secure an agreement on cost sharing.
Additionally, according to AleaSoft, the geographical condition of the Iberian territory makes grid connection with the rest of the European continent a more complicated issue than it could be between two territories that share many kilometres of border.
The importance of interconnection is clearly on the radar though, as Spain and France are working on a new electricity link through the Bay of Biscay, which is expected to nearly double the interconnection capacity between the two countries – increasing interconnection capacity from 2,800MW to 5,000MW.
Commenting to Smart Energy International was grid tech company Gridraven’s CEO Georg Rute: “The big picture is clear.
“As we have moved to a solar/wind-based system, the pace of the change has taken grid operators by surprise. In 2018, there was one Summer in Estonia where solar suddenly met all of summer load, and that was a complete surprise.
“That change has happened so fast and we haven’t built enough interconnectors to move the energy to where it’s needed…If there had been more interconnection between just Spain and France, and I’m speculating now, maybe that cascading effect wouldn’t have happened.”
Grid monitoring
Rute, who for four years was head of the smart grid unit with Estonian TSO Elering, also points to inaccurate line ratings as a potential contributing factor to the grid failure.
Said Rute in a Linkedin post: “With accurate line ratings based on forecasted weather conditions the outcome might just have been different.
“No blackout is identical to the last. But the underlying mechanism is almost always the same: critical components overload and each failure adds stress to the next until the system collapses.
“Inaccurate line ratings can be a contributing factor to the failure. Traditional static ratings of transmission lines do not account for real-time environmental conditions. On hot days with little to no wind, lines can overheat, leading to sagging and potential faults which may then contribute to the cascade.”
According to Rute, with tech like DLR (dynamic line rating) operators would be able to anticipate and plan for such risks.
Indeed, grid enhancing tech like DLR has been gaining interest for some time, with Red Electrica earlier this year installing DLR on line in the Balearic Islands, which were not affected as they are independent of the mainland’s power system.
Inertia and storage
Another possible contributor was a lack of inertia for the power system.
According to VIOTAS, for scenarios such as the Iberian blackout, spinning inertia from conventional generators (for example, coal, gas or nuclear) would help to momentarily stabilise the grid while other generators adjust output to rebalance supply and demand.
According to Reuters, the relatively small share of nuclear and fossil fuel generation in Spain’s power mix translates into a lack of inertia. A long-term solution to this would be to invest heavily in battery capacity to store electricity, as well as technologies for synchronising the grid that are critical to maintaining the 50 Hz frequency.
Storage was also referenced by Phillips, who states how the power outage demonstrated the benefits of distributed, autonomous renewable clean energy systems.
Phillips cites the University of Almería, which remained open thanks to on-site solar and battery storage, while households across Spain and Portugal used EV batteries to bridge local power supply gaps.
