Blackouts and renewables, the “danger” of photovoltaics: «Here's why Sardinia is also at risk»

Could the blackout in Spain, Portugal, and part of France also affect Italy? What risk are we exposed to? And how much did the share of renewable energy produced have an impact? Alfonso Damiano, professor of electrical and electronic engineering at the University of Cagliari, clarified the situation of the networks and security systems to Radiolina. What does it mean, as declared by the Spanish authorities, that the problem occurred in two events? First a "strong oscillation in the flow of energy" and then a "very significant loss of generation"?

According to Damiano, "the photovoltaic systems, "seeing" the disturbance on the grid, reacted by protecting themselves. Therefore, to prevent the interface devices between the systems and the grid from being damaged, they disconnected production. The drop in power was not followed by an increase, but by the multiplication of disconnections. With a cascade effect on the grid".

Is there a “renewable risk” then? Photovoltaic in particular? Damiano clarifies that «production from renewables must be made available for the grid, switching from direct to alternating. Therefore, devices are needed that, technically, ''condition the power''.

They are very sensitive and expensive: therefore, when they ''see'' a disturbance they protect their converter and disconnect. It is required by the regulations».

The central issue is the situation of the grid, which “chases” its adaptation at a speed much lower than the acceleration of renewables. Damiano recalls that the development of the national grid has occurred over decades. «It was designed to receive energy from programmable sources, namely fossil fuels. Now the dynamics of renewable energy injection are not comparable. A slow system, what we have, against the speed of renewables. The effect is what we have seen».