Variable Generators

Over the past few years, most newly added generating capacity has come in the form of weather-dependent variable generators that use grid-following converters. These devices take the DC power from generally PV solar and wind turbine farms and convert them into AC. They use a phase-locked loop (PLL) to synchronize with the grid frequency, to match this AC frequency and the current voltage.

Unfortunately, these devices do not have the ability to absorb or generate reactive power, and instead blindly follow the current grid frequency and voltage, even if said grid was going through reactive power-induced oscillations. Thus instead of damping these oscillations and any voltage swings, these converters serve to amplify these issues. During the 2025 Iberian Peninsula blackout, this was identified as one of the primary causes by the Spanish TSO.

Ultimately AC power grids depend on solid reactive power management, which is why the European group of TSOs (ENTSO-E) already recommended in 2020 that grid-following converters should get replaced with grid-forming converters. These feature the ability absorb and generate reactive power through the addition of features like energy storage and are overall significantly more useful and robust when it comes to AC grid management.

https://hackaday.com/2025/06/30/the-2025-iberian-peninsula-blackout-from-solar-wobbles-to-cascade-failures/

Spain struck by phone and internet blackout – just four weeks after nationwide electricity outage
https://www.lbc.co.uk/world-news/all-major-mobile-networks-emergency-service-lines-down-spain/

All mobile phone networks have gone down across Spain, just four weeks after the country suffered nationwide blackouts.

All leading providers in Spain, including Movistar, Orange, Vodafone, Digimobil, and O2, are suffering from the outage.

Customers are unable to make calls, receive texts or use their mobile data as a result of the blackout, which started at around 5 am according to the website DownDetector.

It has spread through most of the country, with problems reported in all major cities including Madrid, Malaga, Barcelona, Valencia, Murcia, Seville, and Bilbao.

People across the country are reporting no signal, total blackout and internet issues.

People have been calling out their providers on social media because of the outage.

What the blackout in Spain, Portugal says about renewables
Holly Young
The recent power outage in Spain and Portugal has raised questions about the stability of solar and wind power. It also reignited the debate around the phasing out of nuclear energy.
https://www.dw.com/en/spain-portugal-blackout-renewables-wind-solar-energy-grid-v2/a-72606531

Are renewables to blame for the blackout?

Spain is one of the leaders in Europe’s green energy transition and has ambitious targets for renewables to provide 81% of its electricity by 2030. Last year they accounted for a record 56% of the country’s electricity and solar capacity grew at almost twice the European rate.

Shortly before the blackout, renewables accounted for around 70% of Spain’s electricity production, mostly from solar.

This has been used by members of the opposition party and nuclear advocates to suggest that overreliance on renewables was at fault — which both the country’s grid operator Red Electrica de Espana and Prime Minister Pedro Sanchez have disputed. Nuclear currently provides around 20% of the country’s electricity.

While solar and wind are dependent on weather, nuclear can provide a relatively continuous baseload power. However, Sanchez has said there is no evidence more nuclear capacity would have prevented April 28th’s events.

Using the event to speculate against solar is more politically motivated than factually-based, said Rutger Schlatmann, head of solar energy at Helmholtz Zentrum, an energy research center in Berlin.

Schlatmann points to the fact that the high percentage of renewables in the grid was nothing unique. “This has happened many times before.”

Earlier last month, Spain managed to cover 100% of electricity demand on a weekday with renewables alone.

Schlatmann added that countries like Germany also have experienced a high percentage of electricity from renewables while remaining one of the most stable power systems in the world.

How to improve grid stability?

Experts suggest the Spanish blackout highlights grid stability issues more than problems with renewable energy sources.

“It’s mainly that the system has not adapted on the grid scale enough yet to the massive change towards these renewable sources,” said Schlatmann, adding many electricity grids still reflect the demands of a fossil fuel system.

The grid is often described as the most complex system ever devised by humans — encompassing an intricate network of generators, transmission and distribution lines that all need to be kept in balance to function.

Nuclear, coal and gas power plants have huge steel generators that provide large rotating mass — often referred to as inertia

— that can maintain stability if there are fluctuations in the grid.

While removing these from our power grid changes the way a system behaves, it is now possible to replace their stabilizing function, explains Robert Pietzcker, senior scientist at the Potsdam Institute for Climate Impact Research. “You can do virtual inertia, like with these inverters that have grid-forming capabilities.”

Inverters with grid forming capabilities help create a type of “synthetic inertia” and stabilize fluctuations in the electricity system.

The technology to create synthetic inertia — which involves electrical storage and improved control systems — are already available on a commercial scale but aren’t yet implemented on a national or European scale, said Schlatmann.

Other solutions that can also provide stability are flywheels, with the largest in the world today built in Ireland. Flywheels use cylindrical rotors that accelerate at a high speed, storing kinetic energy that can be used quickly when needed.

Better battery storage and increasing flexibility in grid systems is important, said Stefan Thomas, head of energy, transport and climate policy at the Wuppertal Institute in Germany. “More connections to neighboring countries that can help to keep the system in synchronization around the 50 Hertz.” Maintaining a stable 50 Hertz frequency is essential to the stability of Europe’s electricity grid.

He highlights Germany as an example of a country with good connections to other countries and a high degree of stability.

Things such as electric vehicles — which can store power and then feed it back into the grid when needed — could also help provide flexibility, added Thomas.

For regions like northern Europe, that may experience periods of little wind and sun, backup capacity, which could be provided by sources such as hydrogen turbines, may be necessary, said Pietzcker.

Investments into renewables going strong, but more needed for grids

Electric vehicles, chips, AI and air conditioning are helping to fuel a rapid growth in electricity demand.

The technological solutions for a low carbon and stable grid are now available, said Pietzcker. “With today’s understanding of systems, you can design stable systems that will be as resilient based on renewables.”

While grid stability is holding back the roll out of renewables in Europe a little, he says in the EU the commission is strongly pushing for more interconnectedness.

The amount of investment in grids globally needs to double by 2030 to over $600 billion (€532 billion) a year, according to the International Energy Agency. The annual investment into grids has stayed almost the same since 2010, while investments into renewables have nearly doubled.

Major mobile network suffers massive outage in Spain weeks after electricity blackout
It comes weeks after blackouts caused chaos in the Iberian peninsula
https://www.independent.co.uk/news/world/europe/phone-network-down-spain-emergency-services-b2754269.html?utm_medium=Social&utm_source=Facebook&fbclid=IwZXh0bgNhZW0CMTEAAR6JHwbnn-0bW-R2jtjXCTuBNbvajjVrebi6VMaIiIhy7b1gjVXUeTVQscbQPA_aem_aThNjtI9rIdM0H3I_s5siQ#Echobox=1747735996

A nationwide phone network has shut down in Spain just weeks after blackouts brought chaos and heavy financial damage to the country.

Emergency services in a number of regions had to provide new telephone numbers for those in need, after phone lines collapsed following network upgrades by Telefonica.

Landline telephones were the worst affected but all voice services by Telefonica appear to have been affected to some extent, according to reports in Spanish media.

A Telefónica spokesperson said: “We have done some network upgrade work which has affected some companies’ fixed communication services (voice and internet).