By William Opalka

New York won’t need to build too many new power plants for a while.

Demand served by the grid will remain essentially flat over the next decade, staying at about 160,000 GWh annually, according a new report by NYISO.

“Power Trends 2015” says energy efficiency and distributed energy resources will cut peak demand growth on New York’s bulk power system by more than 2,700 MW in 2025 (up from less than 500 MW now), while reducing annual energy usage by more than 14,000 GWh (from about 2,000 GWh). Based on current projections, about 8% of the projected demand of 174,000 GWh will be satisfied by efficiency and DER.

“Changing energy technologies have altered the conventional assumptions about economies of scale. Development of diverse smaller scale power supplies, including solar photovoltaics (PV) that are increasingly affordable to customers, have further challenged traditional models of centralized generation,” the report said.

“We can’t take a ‘one-size-fits-all’ approach to shaping the grid of the future. We need to bolster the strength and stability of the centralized grid while we foster the flexibility and resilience offered by distributed energy resources,” NYISO CEO Stephen G. Whitley said.

Distributed generation — solar PV and other behind-the-meter systems — is central to the Reforming the Energy Vision proceeding before the New York Public Service Commission that will transform the state’s energy landscape. (See New York PSC Bars Utility Ownership of Distributed Energy Resources.)

The report said that since the New York wholesale market started more than 15 years ago, more than 11,600 MW in new generation has been added, with more than 80% of that in the Hudson Valley, New York City and Long Island.

As a result, after years of shrinking, the state’s power surplus — capacity in excess of the state’s reliability requirements — grew to 2,300 MW in 2015, up from 1,900 MW last year. Demand response programs continue at about 1,100 MW.

NYISO credits the creation of a new capacity zone in the Lower Hudson Valley as incenting about 1,000 MW of generation resources returning to the market. (See New Yorkers Upset over NYISO Capacity Zone.)

“Capacity costs in New York are expected to be approximately $400 million lower in the coming year due to the increase in supply driven by the creation of the new zone,” the report said.

Natural gas price spikes during the winter of 2014 pushed average wholesale electric energy prices to $69.30/MWh last year, up from $59.13 in 2013.