By Seaver Wang and Alex Trembath
Excerpt:
Following major power outages in Spain and Portugal—probably the largest blackout in Europe’s history—many are already rushing to exonerate Spain’s wind and solar generation from culpability. Many commentators have already consolidated around a unified stance: it is far too early to blame the blackouts on the renewables supplying two-thirds of the Iberian peninsula’s power at the time. And even if renewables are partly to blame, such grid risks are purportedly of little concern because grid-enhancing technologies are already poised to solve them. But while a total grid collapse at this scale will be multifactorial, it is a simple statement of fact to observe that most of Spain’s solar and wind capacity was wholly unequipped to weather grid fluctuations, possessing none of those shiny new supporting technologies.
Moreover, the parties most guilty of jumping to conclusions are the Spanish political leaders who have driven the expansion of renewable energy in the region. Both the Prime Minister and the Environment Minister summarily rejected any explanation for the blackout that implicated Spain’s solar and wind resources, which at the time of the outage were generating 59% and 12% of total electricity, respectively.
Now, this blackout is not the inevitable outcome of running an electricity system with substantial amounts of wind and solar power. But it is, frankly, exactly what one would expect from the type of energy transition attempted by the Spanish government: breakneck deployment of renewables, a failure to ensure enough spinning generator capacity to maintain stabilizing grid inertia despite widespread understandings of these risks and vocal warnings from grid operators, and underinvestment in grid capabilities that could compensate for renewable energy’s unique technical risks to reliability. It is a testament to the gravity of such risks that an outage has already occurred, two years prior to the start of Spain’s planned phaseout of nuclear energy.
Wind and solar power can contribute meaningfully to large, modern electric grids. But their benefits to the power system—modularity and low marginal costs—have to be balanced against their shortcomings—intermittency, large land area, and transmission requirements. Additionally, most solar and wind farms operating today use simpler equipment that are vulnerable to unexpected shifts in frequency and do not provide spinning or synthetic inertia that can compensate for grid frequency fluctuations. The Iberian outage emphasizes the non-negotiable importance of large-scale investments in grid-enhancing equipment and reliability that occur alongside—if not in advance of—significant penetration of wind and solar onto the power grid. As a 2021 IEA report put it, “to achieve a high share of renewables, the first step is to develop a new way for [inverters] to operate when they start dominating the system.” Spanish policymakers have clearly procrastinated on this first step.
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Running a power system mostly on wind and solar may be theoretically possible, but has yet to be demonstrated on any large grid in the world. Doing so would require a number of “grid-enhancing” solutions that are only just beginning to enter operational service at scale today. Installing “grid-forming” inverters that let solar, wind, and batteries regulate grid frequency and voltage strengthens the grid compared to currently common “grid-following” inverters that cannot adjust to grid fluctuations. A sufficiently large fleet of charged battery systems can also automatically release power in response to loss of generation from one or more power plants, maintaining grid frequency and the balance of supply and demand until reserve generators can come online. Ancillary supporting equipment such as synchronous condensers and static synchronous compensators can similarly provide necessary frequency support to correct for grid fluctuations. Engineers are also devoting increasing attention towards optimizing the parameter tolerances for grid-following inverters and other systems so assets don’t disconnect from the power grid unless truly necessary.
Such solutions involve added costs that renewables proponents have often minimized or entirely neglected to discuss. Spain, clearly, has yet to devote adequate effort to such measures.
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Both Spanish officials and some mainstream media coverage have been quick to dismiss any explanations that implicate wind and solar in the blackouts. “Reliance on renewables is not to blame,” wrote Reuters’ Ron Buosso. “Rather, the issue appears to be the management of renewables in the modern grid.” This dismisses the inherent risks that unaugmented wind and solar can pose to grid operation, and shifts accompanying blame away from the renewables sector and onto utilities and grid operators.
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For too long, climate and clean energy advocates have conditioned themselves to roll their eyes at any commentary suggesting that grid-following wind, solar, and storage cannot do literally everything, everywhere, at all times. Even basic and fundamentally true observations like “the sun doesn’t always shine and the wind doesn’t always blow” have drawn dismissive mockery from some climate hawks. That the Spanish grid collapsed under a bright sun just a half hour past midday fundamentally challenges platitudes that we have already solved the integration challenges of wind and solar power. It is not only okay to admit that wind and solar cannot do everything—it is precisely what this moment needs.
