In the GW range batteries aren’t a great storage solution. At that point you’re basically sitting on a bomb with that much chemical energy storage. Before you get into all the losses from having to temperature stabilize the system. The most efficient/preferred solution is an artificial reservoir. Pump water uphill when you have excess power, run the generator when you need power.
Dams also aren’t permanent structures. There’s been a growing concern for awhile now about dams being managed by financial entities. Because local governments couldn’t/wouldn’t run them after their expected lifespan ran out in the 80s/90s they were seen as a reliable investment. Especially if you cut costs. On a dam basically the only costs to cut are maintenance.
Dams being decommissioned instead of failing is a better strategy.
Disney hoped the clause would be enforceable. At least part of the reason Disney settled out of court was because they didn’t want to challenge that assumption.
You can put whatever clauses you want in a contract. The law still trumps those contracts if it ever comes to enforceability.