This page provides daily CAISO battery storage dispatch data, ancillary services procurement, and LMP prices. Data updates automatically each morning.
OpenNash energy consulting: We build automated market intelligence pipelines, storage dispatch analytics, and custom energy data workflows. See AI consulting.
What is CAISO?
The California Independent System Operator (CAISO) manages the electricity grid serving 80% of California. As a nonprofit, CAISO doesn't own generators or transmission lines - it operates the wholesale electricity market where power is bought and sold.
CAISO runs two markets:
- Day-ahead market: Opens 7 days early, closes at 10am the day before. Generators bid to supply power for each hour of the next day.
- Real-time market: Balances supply and demand every 5 minutes based on actual conditions.
The storage data below shows how California's battery fleet participates in these markets. Learn more at CAISO Market Operations.
Quick Stats (2026-01-22)
| Metric | Value |
|---|---|
| Peak Discharge | 5,074 MW |
| Peak Charge | 8,892 MW |
| Charging Intervals | 65.3% |
| Discharging Intervals | 34.7% |
| Top AS Product | Regulation Mileage Down (67,035 MW) |
| Highest Price Hub | NP15 ($42.49/MWh avg) |
| Data Source | CAISO via gridstatus |
Storage Dispatch by Hour
Battery storage output by hour. Positive values indicate discharging (supplying power to grid). Negative values indicate charging (consuming power from grid).
| Hour | Total (MW) | Standalone (MW) | Hybrid (MW) | Status |
|---|---|---|---|---|
| 00:00 | -718 | -716 | -2 | Charging |
| 01:00 | -1,070 | -1,053 | -22 | Charging |
| 02:00 | -1,386 | -1,356 | -30 | Charging |
| 03:00 | -1,823 | -1,685 | -140 | Charging |
| 04:00 | -1,056 | -1,028 | -20 | Charging |
| 05:00 | -87 | -76 | +2 | Charging |
| 06:00 | +2,398 | +2,341 | +78 | Discharging |
| 07:00 | +2,954 | +2,861 | +76 | Discharging |
| 08:00 | +292 | +425 | -153 | Discharging |
| 09:00 | -1,449 | -1,271 | -187 | Charging |
| 10:00 | -4,644 | -4,099 | -563 | Charging |
| 11:00 | -6,919 | -6,210 | -726 | Charging |
| 12:00 | -8,080 | -7,509 | -578 | Charging |
| 13:00 | -8,135 | -7,490 | -630 | Charging |
| 14:00 | -5,092 | -4,653 | -419 | Charging |
| 15:00 | -1,102 | -905 | -151 | Charging |
| 16:00 | +1,638 | +1,454 | +196 | Discharging |
| 17:00 | +4,558 | +4,187 | +384 | Discharging |
| 18:00 | +4,337 | +3,940 | +389 | Discharging |
| 19:00 | +3,657 | +3,417 | +232 | Discharging |
Day-Ahead LMP Prices
Locational Marginal Prices at CAISO trading hubs. NP15 = Northern California, SP15 = Southern California, ZP26 = Central California.
| Hub | Avg ($/MWh) | Peak ($/MWh) | Min ($/MWh) |
|---|---|---|---|
| NP15 | $42.49 | $49.64 | $36.86 |
| SP15 | $41.81 | $48.25 | $36.75 |
| ZP26 | $42.28 | $48.95 | $36.33 |
How LMP Pricing Works
Locational Marginal Price (LMP) represents the cost to deliver one additional megawatt of electricity to a specific location. LMPs have three components:
- Energy cost: The price of generating power
- Congestion cost: Added when transmission lines are constrained
- Losses: Energy lost during transmission
Why do NP15, SP15, and ZP26 prices differ? Transmission constraints. When lines between Northern and Southern California are congested, local generators must fill the gap - often at higher cost.
Battery operators arbitrage these price differences: charge when LMP is low (midday solar), discharge when LMP is high (evening peak). Learn more: How Locational Marginal Pricing Markets Work.
Ancillary Services Procurement
Day-ahead ancillary services procurement for CAISO. Batteries are major providers of regulation and reserves.
| Product | Total (MW) | Total Cost ($) |
|---|---|---|
| Regulation Down | 21,187 | $23,124 |
| Non-Spinning Reserves | 21,015 | $17,431 |
| Regulation Up | 20,328 | $27,530 |
| Spinning Reserves | 16,717 | $12,729 |
Ancillary Services Explained
Ancillary services keep the grid stable by balancing supply and demand in real-time. CAISO procures four products:
| Service | Response Time | What It Does |
|---|---|---|
| Regulation Up | Seconds | Increases output to raise grid frequency |
| Regulation Down | Seconds | Decreases output to lower grid frequency |
| Spinning Reserves | 10 minutes | Backup power already synchronized to grid |
| Non-Spinning Reserves | 10 minutes | Backup power that can start within 10 min |
Batteries dominate these markets because they respond faster than gas plants. A battery can go from charging to discharging in milliseconds - gas turbines need minutes to ramp. Learn more: CAISO Ancillary Services Guide.
Understanding the Data
Storage Dispatch Patterns
California's battery fleet follows a predictable daily cycle:
- Morning (6am-10am): Batteries may charge or discharge depending on solar ramp
- Midday (10am-3pm): Heavy charging during solar peak when prices are lowest
- Evening (4pm-9pm): Heavy discharging during demand peak when prices are highest
- Night (9pm-6am): Mixed behavior, often charging on low off-peak prices
The Duck Curve: Why This Pattern Exists
California's storage dispatch pattern reflects the famous "duck curve" - a graph that shows net electricity demand throughout the day. The curve got its name because it resembles a duck:
- The belly (10am-3pm): Solar generation floods the grid, pushing net demand to its lowest. Batteries charge during this window, often when prices go negative.
- The neck (4pm-7pm): Solar drops off just as people come home and turn on air conditioning. Demand ramps up 10-15 GW in just 3 hours.
- The head (7pm-9pm): Peak demand hits after sunset. Batteries discharge at full capacity to meet this need.
Today's data shows this pattern - look at the Status column in the hourly table to see the duck curve in action. Learn more: EIA Duck Curve Explanation.
Why This Matters
- Developers: Peak discharge hours indicate revenue potential for new projects
- Traders: Charge/discharge patterns correlate with price spreads
- Operators: AS procurement shows ancillary revenue opportunities
- Analysts: Track the growing role of storage in grid operations
Methodology
Data is fetched daily from CAISO via the gridstatus open-source library:
- Storage: Real-time 5-minute intervals from CAISO Outlook
- LMP: Day-ahead hourly prices from OASIS API
- AS: Day-ahead procurement from OASIS API
Timestamps are Pacific Time (PT). Data typically updates by 6am PT.
OpenNash energy consulting: We build automated market intelligence pipelines, storage dispatch analytics, and custom energy data workflows. See AI consulting.