The massive issue I have with these sources is their reliability. Scotland can produce 98% from wind because they can sell the excess or buy when in deficit from their neighbours who modulate their coal/gas plants. If all its neighbours switch to similar methods, I don't see how we can have reliability on a wide scale.

Usual fluctuations (eg. no photovoltaic by night, more wind in the afternoon) can be planned for, but local events such as big clouds or no wind are frequent but have a great impact on