Energy Storage

Storage could replace as much as 500 MW of peakers: report

Energy storage could replace as much as 500 MW of peaking capacity in New York, according to a new report from the state’s Department of Public Service (DPS).

The report, issued July 1, conducted a unit-by-unit analysis of the operational and emissions data of about 4,500 MW of peaking power plants across the state, but “almost entirely” concentrated in New York City, Long Island and in the Lower Hudson Valley. The analysis used data from 2013 because it was the peak demand year for the New York Independent System Operator.

The study found that at least 275 MW, or about 6%, of the state’s peaking fleet are candidates for replacement with 6-hour storage facilities sized to the 2013 peak output. If the storage duration is stretched to eight hours, about 500 MW of peakers would be candidates for replacement.

If the capacity of the energy storage facilities is oversized, the numbers are even larger. Sizing storage facilities at 125% of peak output, for instance, would result in 224 MW of replacement candidates at the 4-hour duration level, the report found. For 6-hour and 8-hour duration energy storage facilities, the replacement potential rises to 467 MW and 1,607 MW, respectively. The report’s authors added, however, that oversizing an energy storage facility presents tradeoffs between costs and duration.

The authors also noted that the study did not look at charging constraints associated with multiple concurrent peaking plant replacements and warned that it might not be possible to realize all the energy storage potential identified in the study because of potential charging capacity constraints.

The study, The Potential for Energy Storage to Repower or Replace Peaking Units in New York State, examined two potentials “paths” for replacing or repowering peaking plants.

The first analyzed the unit-by-unit data to determine the potential to replace or repower peakers with energy storage or energy storage paired with solar power. The second examined the ability of energy storage or energy storage paired with solar power to bring peaking plants potentially affected by the state’s proposed regulations concerning Ozone Season Nitrogen Oxide (NOx) Emission Limits for Simple Cycle and Regenerative Combustion Turbines into compliance.

There is about 4,500 MW of capacity in New York that are potentially subject to the NOx rule, although certain units installed after 1990 may not be impacted as they already have emission controls.

On the second path analysis, the report found that 864 MW of capacity could be hybridized with 4-hour energy storage to meet the pending NOx rules, while 1,125 MW and 1,407 MW could be hybridized using 6-hour and 8-hour storage facilities, respectively. If energy storage is paired with solar power, the capacity with the potential for hybridization increases to 1,550 MW for 4-hour storage, 1,804 MW for 6-hour storage, and 2,352 MW for 8-hour storage.

The study was conducted as a result of a recommendation of the Energy Storage Deployment Order issued by the Public Service Commission in December 2018 that established a goal to have 1,500 MW of energy storage in place by 2025 and 3,000 MW of storage in place by 2030.

The DPS study also says that a “more detailed and thorough benefitcost analysis would need to be performed to understand the true economic viability of the replacement and/or hybridization options presented in this analysis.”

But overall, the study says, the findings suggest there is an opportunity to consider replacing or hybridizing “a substantial portion of the peaking units” subject to the proposed NOx rule with a fleet of storage resources paired with solar power.

NREL study focused on replacement of peakers with storage

A study released by the National Renewable Energy Laboratory in June found that a “substantial portion” of peaking capacity in the United States could be replaced by energy storage facilities.

The capacity of the national peaking power fleet is about 261 GW and about 150 GW of that capacity is likely to retire over the next 20 years, NREL estimated. That could lead to the potential for about 28 GW of 4-hour battery storage that could serve as peaking capacity, NREL said.