Monday’s devastating blackout in Spain is raising questions about the country’s massive reliance on solar and wind power for electricity — and whether the new power sources may have played a role. Spain’s socialist government has faced increasing pressure to explain what went wrong on Monday,

New details are emerging, which is why a large-scale blackout occurred in Spain, which lasted more than 10 hours and hit millions of Spaniards. The statements of the operator of the country's energy system differ from the original version of

Some media outlets have speculated that Spain’s April 28 blackout may have been caused by a disconnected solar plant, but DNV grid analyst Andrea Mansoldo tells pv magazine that it was likely due to a combination of grid weakness and low-frequency oscillations.