California BESS Operators Left $98 Million Behind. Here’s What the Bidding Data Shows.
July 20, 2026
A new analysis from Gridmatic puts a hard number on something battery storage operators have long suspected: poor bidding strategy is costing real money. According to their findings, BESS assets operating in California's grid left approximately $98 million in revenue unrealized due to suboptimal participation in energy and ancillary service markets. That's not a rounding error. It's a structural problem worth understanding before you commission your next asset.
The Gap Between Installed Capacity and Captured Value
California has added significant battery storage capacity over the past several years. The hardware is there. The grid needs it. But owning a BESS and extracting maximum value from a BESS are two different things, and the Gridmatic analysis makes that gap visible in dollar terms.
The core issue is market participation. California's CAISO operates multiple revenue streams simultaneously: the day-ahead energy market, the real-time market, and ancillary services like frequency regulation and spinning reserves. Each market has its own pricing dynamics, timing windows, and dispatch requirements. A battery that's optimized for one stream is often leaving value uncaptured in the others.
Suboptimal bidding doesn't mean incompetent operation. It often means the bidding logic hasn't kept pace with how market conditions are evolving. Price spreads shift. Ancillary service demand fluctuates with grid conditions and weather. A static or rules-based bidding approach that worked well twelve months ago may underperform significantly today.
For C&I organizations that own or co-invest in battery assets, this matters beyond the revenue line. If your BESS is structured with a revenue-sharing component or if battery ROI projections depend on market participation income, a persistent bidding gap erodes the financial case that justified the investment in the first place.
Ancillary Services Are Where the Money Gets Left Behind
The Gridmatic analysis points specifically to ancillary service markets as a primary source of missed revenue. This tracks with how CAISO pricing actually behaves. Ancillary service prices can spike sharply and briefly, particularly during periods of grid stress. A battery positioned to respond earns significantly more than one that's committed elsewhere or bidding conservatively.
The challenge is that capturing ancillary service value requires your dispatch logic to anticipate those windows, not just react to them. Day-ahead bidding decisions lock in positions before real-time prices are known. If your system is consistently bidding into energy arbitrage when ancillary service compensation would have been higher, you're making a rational-looking decision with incomplete information.
This is where machine learning-based optimization, like the approach Gridmatic uses, starts to outperform rule-based dispatch systems. The models can weigh probabilistic outcomes across multiple market products simultaneously and adjust bid positions as new information becomes available. That's harder to replicate with a fixed bidding schedule.
For asset owners evaluating their current operational approach, the right question isn't whether your battery is operating. It's whether the entity managing your dispatch has the tools and market data to compete effectively across all available revenue streams, not just the most straightforward ones.
What This Means for BESS Procurement and Contracting
If you're in the planning stages of a battery storage project, the Gridmatic findings should shape how you evaluate operational partners and structure your agreements.
First, don't treat dispatch optimization as a secondary consideration. The hardware decision gets most of the attention during procurement, but long-term asset performance depends heavily on how the battery is bid into the market. An operator with a sophisticated optimization platform will, over time, outperform one relying on manual or rules-based bidding, often by a meaningful margin.
Second, ask direct questions about ancillary service participation. Can your proposed operator bid into BAMUSA (Balanced Ancillary Market Unit for Storage Assets) and other ancillary products? Do they have a track record in CAISO markets specifically? How do they handle the trade-off between energy arbitrage and ancillary service commitments?
Third, build performance accountability into your contract structure. Revenue capture benchmarks, reporting on market participation by product type, and regular strategy reviews are reasonable terms to request. A capable operator won't resist this kind of transparency.
The $98 million figure in the Gridmatic analysis is an industry-wide number, but it's made up of individual asset shortfalls. Some operators are capturing value efficiently. Others aren't. The difference is strategy, not hardware.
Planning Around Market Participation From the Start
The broader lesson from this analysis is that BESS value optimization isn't a post-commissioning problem. It starts during project development.
When BioStar works with clients on battery storage projects, we factor market participation strategy into the financial modeling from the beginning. What revenue streams are realistically accessible given the asset's configuration, location, and interconnection? What operational partner is best positioned to maximize capture in that specific market? How do projected revenues hold up under conservative assumptions about bidding performance?
These aren't abstract questions. They determine whether the project pencils out and whether it continues to deliver against its financial case over a ten-year operating life.
California's storage market is deep and active, which means the upside from optimized bidding is real. But that same depth means competition for ancillary service revenue is stiff and getting stiffer as more capacity comes online. Assets that aren't actively optimized will fall further behind, not just hold steady.
If you're evaluating a BESS project in California or reassessing the performance of an existing asset, start by understanding where your dispatch strategy stands relative to what the market is actually offering. The gap the Gridmatic analysis identified isn't inevitable. It's a planning and operational problem, and those can be solved.
Reach out to the BioStar team to talk through how market participation strategy fits into your storage project from day one.