I once worked for a co-operative, and it was by far the most poorly run company I have ever worked for or with. The control of the company was so far removed from shareholder control that the management was basically only accountable to their creditors (i.e. banks). The company had every corporate pathology you could imagine and then some. It was orders of magnitude worse than a Fortune 500 dinosaur I also worked for.

The cooperative was performing poor profit-wise while middle management lined their pockets. If it was not a cooperative, their share price would have been in the gutter, and someone would have bought up enough shares for cheap to fire the leadership and replace it with people who are competent, and then benefited from the increasing share price of having the company ran competently.

There were quite a few small energy co-operatives in the UK, mainly set up by municipalities.

When wholesale energy prices spiked last year, followed by a cap being applied to the prices that they could charge, they weren't hedged and several ended up going bankrupt.