[numitus]

Green power is working like a business of child of rich parent. The child may do the business, but in case of problem, then can alway ask his daddy(fossil fuel) to help. There is no sence to analize portugail or sweden seprarately, because they are a part of EU energy system and can infinitely get energy in case of lack of wind or solar.

For e.g. in germany 60% of energy is produced from renewable source, but there are weeks when it is only 10%. So you have to have coal or gas station to compensate it