[moooo99]

> 1. They could export the surplus. No?

Yes, and that is in fact done. However, there it is still a bad deal with negative electricity prices.

> Isn't cheaper electeicity a good thing for the manufacuring industry?

It technically is, but its not as simple as that. Industrial manufacturing is a relatively steady load, which means the consumption is constant. The lowest prices do not matter all that much, the average price does. And that average price is relatively high here, even for industrial consumers.