Why wouldn't the State build power stations? As I said earlier the State can get funds cheaper and for longer terms than private companies. It does not have to pay dividends to shareholders and profits can be directed back into the core business - electricity generation.
I have not been, and never will be, a Labour supporter, but I am not against nationalisation, and I am not alone.
And why would the bad practices of the past come back? The laws to prevent them are already in place. Are you saying that Labour, under Corbyn, would repeal those laws? There is not one jot of evidence to say so.