Change is afoot in the Western Interconnect.

With more than 38 balancing authorities spread out across a sprawling landscape, the West has long-resisted organizing into regional markets like those in the East. But the need to integrate renewable energy and meet other reliability challenges is prompting a revived interest.

Already in place is the California ISO's Energy Imbalance Market. Launched in November 2014, the market is automatically balancing supply and demand on five-minute intervals between the California ISO and Berkshire Hathaway Energy utilities NV Energy and PacifiCorp. Grid authorities estimate the market has already saved market participants tens of millions of dollars, with more to come as new participants join.

There could be bigger changes ahead. While the EIM only impacts the relatively small amount of energy traded in real time, the California ISO and PacifiCorp in April 2015 laid out a plan to explore making the multi-state utility a full member of the RTO. Such a move could produce billions of dollars in savings, according to a study commissioned by the utility and the grid operator and enable the development of renewable energy across the West.

But not all are excited about the idea. Expanding the California ISO beyond California would mean giving other officials in other states a say in its operations and policies, and opens up a web of questions about how the grid would meet different states' needs.