New York is set to join the ranks of a small but growing number of pioneering states that are setting targets for energy storage as wind, solar and other renewable energies supply increasing amounts of power to their electric grids.

So far, only a few states have laws demanding that utilities meet targets for energy storage—including California, Oregon, Massachusetts and Nevada—and their targets vary. Massachusetts drew criticism today when it announced its first targets, which energy experts considered well below what will be needed.

New York’s legislature has now passed a bill that would join those states by asking its Public Service Commission to set targets for energy storage in New York by as early as January of next year.

“Anyone in the business knows storage is critical to making intermittent energy a reality. Because of this, New York has got to take a leadership role,” said Westchester Assemblywoman Amy Paulin, who co-sponsored the bill. She said she was confident that Gov. Andrew Cuomo would sign it.

Under Cuomo, New York moved to significantly upgrade its green energy ambitions. In 2015, the state set goals of having 50 percent of electricity generated by carbon-free renewables by 2030. The challenge from renewables like wind and solar is, of course, that their generation is variable and, therefore, storage is crucial to maintaining continuity of energy flow.

There are several ways to store energy from intermittent generators like wind and solar and save it for later use. Some are already widely deployed, like pumping water behind hydroelectric dams; others are coming on fast, like banks of modern batteries. As wind and solar grow, the competition between storage technologies is expected to grow brisker.

Like legislation in other states, the New York State bill gives regulators a great deal of flexibility to set targets for both the amount and type of storage. The only criteria is that it be the best available and most cost-effective technology. The objectives are clearly to create more reliability in the system to support zero-carbon energy sources.

California and Oregon currently set the standards for energy storage in their states.  California has directed its utilities to build 1.35 gigawatts of energy storage—toward which they have already made substantial progress including opening the largest lithium ion storage facility in the United States. Nevada is writing its standards now. Additionally, Maryland offers an energy storage tax credit to encourage adding more storage.

The Massachusetts Department of Energy Resources just announced its energy storage goals, but only required utilities to have 200 megawatt-hours of energy storage by 2020. That was very disappointing to many energy experts who had hoped they might set a new high bar.

Tim Fox, vice president of Clearview Energy Partners, a research firm for institutional investors and corporate strategist, was one of those who had been expecting more. “We consider 200 megawatt-hours to be a comparatively modest target in relation to expectations,” he said. “The 200 would represent considerably less than one percent of the state’s total annual electricity consumption projected in 2020.”

Paulin said the legislature in New York didn’t set hard targets in part because energy storage technology is still very much evolving, but she said she and her colleagues were clearly sending the message that they hoped New York’s regulators would be ambitious. “We want to push them as far as they can go,” she said.