Energy storage resources combined with wind or solar generators offer the ability to “firm” the output of variable resources, increasing their resource adequacy value and offering operational benefits, PJM’s Andrew Levitt told the Federal Energy Regulatory Commission on July 23.
Levitt, Senior Market Design Specialist, testified at a FERC technical conference convened to discuss operational and market issues raised by a growing interest in hybrid resources. These facilities consist of more than one generation type at the same point of interconnection. In the current industry climate, the majority are solar generation paired with battery energy storage.
Levitt participated in the Market Design/Operation for Hybrid Resources panel, along with Michael DeSocio of NYISO; Ted Ko of Stem Inc.; Rachel McMahon of Sunrun Inc.; Gabe Murtaugh of California ISO; and Mike Tabrizi of DNV GL.
Hybrid resources are able to participate in the PJM energy, capacity and ancillary services markets under current rules, Levitt noted. But because of the increasing interest, PJM is working with stakeholders to clarify the status quo for hybrid market participation and operational requirements, as well as to consider certain enhancements to further opportunities for hybrid resources to participate in markets.
More than 13,000 MW of hybrid resources are currently in the PJM interconnection queue, which has been successfully processing combined resources for years, Levitt said. Most of these new resources represent solar-storage combinations.
Within PJM’s footprint, a number of wind and battery resources and solar and battery resources are located at the same site, but some of the market and operational considerations are simpler because the two components do not act in coordination with each other.
The stakeholder process concerning hybrids will start in August with a new subcommittee – the DER and Inverter-based Resources Subcommittee (DIRS).
Hybrid resources offer many potential benefits, Levitt said, including:
- The combination mitigates some of the local operational issues associated with fluctuating output of variable energy resources.
- By allowing variable resources to provide a steadier stream of energy, hybrids offer owners the option to maintain or increase their resource adequacy value as the resource mix changes and their capacity value is impacted.
- They provide resource owners the flexibility to produce more power during times of higher economic and reliability value (that is, during times of higher locational marginal prices), and also the flexibility to provide ancillary services such as operating reserves.
In addition to the new subcommittee, capability rules for hybrids in the capacity market are currently being pursued as part of discussions being held at the Capacity Capability Senior Task Force. These would enhance the status quo rules.