It is a lot cheaper to build transmission lines compared to providing storage. In the future the vast majority of electricity will come from wind and solar. If

It is a lot cheaper to build transmission lines compared to providing storage. In the future the vast majority of electricity will come from wind and solar. If production does not match consumption then it is almost always the best option to move the electricity somewhere else. (That said: Of course storage will be needed, but only if there are no better options to balance the grid otherwise.)