AleaSoft Energy Forecasting, May 13, 2025. The transition to a 100% renewable electricity system also involves rethinking the technical foundations that have underpinned its stability for decades. One of these pillars is the system inertia, traditionally provided by synchronous generators. In a system dominated by renewable technologies, this inertia disappears, posing a challenge for maintaining grid stability. In this new context, technologies such as batteries with grid‑forming inverters emerge as a solution to provide virtual inertia and reinforce the resilience of the electricity system.
In recent years, an unprecedented energy revolution has taken place. The massive penetration of renewable technologies has completely changed the map of electricity generation in Europe. But there is something that is hardly mentioned outside the more technical environment, and which will be key to ensure that this new model does not end up in unstable chaos: the inertia of the electricity system.
Until recently, inertia was naturally guaranteed by the synchronous generators of thermal, nuclear or hydroelectric power plants. Their large rotating masses acted as shock absorbers that smoothed out any disturbances. It was an invisible but vital superpower: it helped to keep the frequency of the system stable in the face of any sudden variation.
But renewable technologies do not rotate. Or, at least, they do not naturally provide inertia. Solar and wind farms are coupled to the grid via electronic inverters. This means that, in a 100% renewable system, we lose one of the elements that has contributed most to avoiding blackouts over the last 100 years.
In addition, the traditional inertia model has a structural limitation: it requires the masses to be in motion beforehand, which implies start‑up time, fuel consumption and operating costs, even if they are not actively generating energy. It is a heavy, inefficient and polluting system.
In contrast, batteries equipped with advanced power electronics, such as grid‑forming inverters, offer a radically different solution: they can inject power instantaneously, provide virtual inertia, stabilise the grid and, all this, without emissions and with a much more efficient investment. They do not need to be spinning: their response is digital, clean, and in real time.
In the coming years, the focus cannot be solely on the price or the amount of energy generated. It will be essential to focus on the system stability, its responsiveness and resilience to disturbances. Because in an electricity system dominated by renewable technologies, the real risk will not be the lack of sun or wind, but the lack of inertia that guarantees its equilibrium.
The good news is that, although the future will not have spinning masses, it will have digital solutions capable of reacting in milliseconds. A new paradigm, lighter, cleaner and much faster.
AleaSoft Energy Forecasting’s analysis on the prospects for energy markets in Europe and batteries
On Thursday, May 22, AleaSoft Energy Forecasting will hold the 55th edition of its monthly webinar series. This time, in addition to the usual analysis on the evolution and prospects of European energy markets, the webinar will focus on batteries. Topics such as the importance of demand forecasts and the secondary band, the benefits according to the degree of battery use, their financial optimisation and the regulatory framework for energy storage, including subsidies and capacity payments, will be discussed. Javier Adiego Orera, CEO and co‑founder of 7C Energy, will be the guest speaker.
In the second part of the webinar in Spanish, there will be an analysis table with the participation of Kiko Maza, Managing Director at WeMake Consultores, and Luis Atienza Serna, former Minister of the Spanish Government and former President of Red Eléctrica. The analysis table will also address aspects such as hybridisation with wind energy, ancillary services and transmission and distribution grids.
Source: AleaSoft Energy Forecasting.
