While this is really encouraging, its important to realise that during March Portugal still needed to generate or import some thermal power to meet demand during some periods.

Because they can export power outside the county borders they can over produce to make this up. Over the month the net renewable generation met the net demand. I think this highlights the challenges we still face to move to a genuine 100% renewable system, the point at which storage moves below the close to and below the long run cost of keeping a thermal generator will be when this gets really exciting.

A good simple summary here: https://insights.globalspec.com/article/8465/portugal-s-renewable-power-generation-exceeded-total-consumption-in-march