Enron is the poster child of how opening the energy grid to an unregulated free market makes it ripe for price rigging and manipulation. Enron was famous for trading strategies like "Fat Boy" and "Death Star" where they would do things like submit fake energy schedules to create the illusion of congestion on transmission rights they own to collect payments for relieving the congestion the next day, which wasn't actually going to happen. Energy markets need regulations and oversight to prevent bad actors from ripping off utilities, which ultimately get passed on to ratepayers via higher rates.