What kind of control over voltage & frequency can these “green power” sources provide? These are vital in any major power sources for a nation. I never went to college; graduated from high school & I understand this, so why do we depend on college educated “geniuses” to figure this out?
The traditional power generators are based on turbine engines. Steam turbines for nuclear, coal and oil-fired generators. Gas turbines for natural gas generators. These generators have rotational generators where the rotational speed and generator winding count determine the frequency output (50 cycles per second in Europe and many other places, 60 for the USA). The torque into the generator determines the power put into the grid. The generator will sync to the frequency of the grid and if more power than demand is put into the grid than the generator will "slip" it's phase slightly ahead of the grid (360 degrees is one cycle). If the generator is falling behind in supplying power to the grid then the phase will slip backward. The control of the grid depends on matching power supply and demand. The phase slip is how you know if you are supplying too much torque or too little.
The cited sources stated that the frequency was falling below 50 cycles per second (Hz) and that the European grid connection to Spain and Portugal was disconnected. That indicates that the power put into the grid from Spain and Portugal solar and wind and traditional generation was not enough to meet demand and that the European grid could not supply enough power to make up the difference. This inability to supply the power caused the European generators to have pole slips and the thing that happens when the phase slips too much is that the frequency slows down and if the phase slips more than (I think it may be 90 degrees, but it could be 180 degrees) then the generator starts "skipping poles" which is the grid power slamming the generator through a partial rotation to get back in phase which is a violent event which can destroy the generator. If the European grid was being dragged down then at a certain point it will disconnect from the branch draining power to avoid damage to generators. The solar and wind generators produce direct current (DC) which must use inverters to change to alternating current (AC) power and match the grid frequency. I am not sure how the green energy power input is regulated, but as long as it is not too large a percentage then the traditional generators could regulate everything. It looks to me like there was not enough traditional generation capacity in the European grid to make up for the shortfall in Spain and Portugal. This is exactly what the skeptics have been saying would happen.