CAISO’s Cluster 16 application window this October was the first time developers could add new projects to the queue since 2023.

​The preliminary results hold 226 requests, totaling 88 GW by rated power capacity, or 62.6 GW at the point of interconnection (POI). Energy storage features in 90% of requested rated power capacity across standalone and co-located projects.

Key takeaways

• Cluster 16 is storage-led. Standalone BESS (29.5 GW) and solar + storage (48.4 GW) make up most of the request list.
• Fewer, smaller applications. Cluster 16's 88 GW is 75% below Cluster 15's 347 GW in 2023, as merchant BESS revenues track 64% lower than three years ago.
• Batteries continue to aim for resource adequacy. 98% of standalone BESS capacity requests full capacity deliverability. No standalone solar does.
• New transmission is pulling capacity out of state. Nevada, Arizona and New Mexico host 13.1 GW, 20% of the cluster.

Cluster 16 received far fewer projects amidst low wholesale market revenues

Cluster 16’s total 88 GW intake by rated power is 75% lower than Cluster 15 initial intake of 347 GW.

This sharp drop in applications reflects a market where wholesale merchant revenue can no longer support investment decisions without greater certainty.

Merchant revenues for CAISO batteries averaged $6.67/kW-month in 2023. So far in 2026, they average $2.40/kW-month, 64% below 2023.

This merchant revenue environment appears to have resulted in fewer developers willing to take the risk to invest in new projects.