Europe’s move to 15-minute power trading can boost battery arbitrage revenues by ~14% and lift ROI by 3%. Here’s how AI-optimised BESS can capture that value.
Most European battery projects are underwriting on razor-thin margins, then trying to survive 20 years in markets that change every six months. A 3% uplift in return on investment doesn’t sound dramatic on paper—but across a multi‑MW portfolio, it’s the difference between “nice pilot” and “this asset class scales”.
That’s why the shift to 15‑minute trading and settlement in European power markets matters so much for battery storage, and why it sits squarely in the heart of the green technology story we’re telling in this series: smarter software, smarter markets, and smarter assets working together to decarbonise the grid.
The latest Rystad Energy analysis shows that simply moving from hourly to 15‑minute trading intervals can lift arbitrage revenues by around 14% on average, and increase long‑term project ROI by roughly 3% over 20 years. For a grid‑scale BESS, that’s real money—and it’s a structural change, not a one‑off subsidy.
In this post, I’ll break down what’s changing, how much value is actually on the table, where AI and optimisation software come in, and what developers, investors and corporates should do about it now.
Why 15-Minute Trading Is Such a Big Deal for Batteries
The core impact of 15‑minute trading is simple: more granular prices mean more chances for flexible assets to earn money.
European day‑ahead markets like EPEX SPOT traditionally cleared in 24 hourly blocks. Since late September, they’ve opened up bidding in 96 quarter‑hour intervals per day. Intraday markets already moved to 15‑minute granularity earlier in the year.
For batteries, that changes three things:
-
More arbitrage windows
Instead of buying cheap power at, say, 01:00–02:00 and selling 18:00–19:00, a BESS can now target sharp price spikes within those hours—like 18:15–18:30—where volatility is highest. -
Better alignment with renewables
Solar and wind don’t ramp in neat hourly steps. They vary minute‑by‑minute. Shorter settlement windows let markets “see” those variations and price them. Batteries that react fast can monetise the swings. -
More value for flexibility, less for inflexible plants
Slow‑ramping thermal units struggle to respond to quarter‑hour volatility. Batteries, demand response and smart EV charging thrive in it. The market design quietly shifts value toward green flexibility assets.
The result, according to Rystad’s work: arbitrage profits in some European countries could rise 15%–25%, with an average uplift around 14% when moving from hourly to 15‑minute trading.
This matters because green technology doesn’t scale on “coolness”—it scales on bankability. A 3% ROI uplift, driven by structure rather than subsidies, is exactly the kind of signal institutional capital pays attention to.
Where the Money Is: Country-Level Winners and Laggards
Not every market benefits equally from 15‑minute settlement. The uplift depends on how volatile prices already are—and what’s driving that volatility.
High-volatility, high-upside markets
In countries with less flexible generation and high shares of variable renewables, prices can swing sharply within an hour. Think: clouds over a solar‑heavy system, or sudden wind output drops.
Rystad’s examples:
- Austria
- More than 25% increase in potential arbitrage earnings with 15‑minute trading.
- Under optimistic assumptions (perfect foresight, one full cycle per day), a BESS could earn about US$107/MWh from pure arbitrage.
These are exactly the kinds of markets where well‑optimised batteries become core grid assets, not “nice‑to‑have” support.
More flexible systems, smaller gains
In markets with abundant flexible generation—typically hydropower and quick‑ramping gas—prices are smoother. There’s less intra‑hour volatility to capture.
- Portugal
- Expected arbitrage uplift around 3%, far below the continental average.
- Estimated arbitrage revenue around US$89/MWh under current conditions.
Norway, with dominant hydro, sits in a similar category: great for clean baseload and ancillary services, but less of an intra‑hour arbitrage playground.
What this means for strategy
If you’re developing or investing in BESS right now:
- Location choice matters even more. Don’t just look at average prices; study intra‑day volatility distributions and how they shift with renewables build‑out.
- Revenue stack design changes. In high‑volatility markets, arbitrage becomes a bigger share of the stack; in flexible systems, you may still lean harder on capacity and ancillary services.
- AI‑driven optimisation becomes non‑optional. The more intervals and volatility you have, the more value there is—if you can actually capture it.
Lessons from Australia’s 5-Minute Settlement
If you want a preview of where Europe is headed, Australia already ran the experiment.
In 2021, the country’s National Electricity Market (NEM) shifted from a 30‑minute to a 5‑minute settlement framework. That’s 288 intervals per day—three times more granular than Europe’s new 15‑minute design.
Rystad highlights two key results:
- In New South Wales, yearly arbitrage revenues for batteries have increased by around 20% since 5‑minute settlement was introduced.
- In Victoria, arbitrage revenues for 1‑hour strategies rose by about 15%.
Sepehr Soltani from Rystad puts it bluntly:
“Finer time intervals have consistently increased arbitrage profits.”
There’s a second, equally important lesson from Australia: humans can’t trade this manually anymore.
Sahand Karimi, CEO of BESS optimisation specialist OptiGrid, points out that in a 5‑minute world you simply don’t have the time to sit, assess, and click your way through volatility events. By the time a human trader reacts, the window’s already closed.
Profitable participation in such granular markets requires:
- Automated forecasting of prices, demand, and renewable output.
- Scenario‑based bidding that places volume across multiple markets (day‑ahead, intraday, balancing) simultaneously.
- Real‑time response to events—price spikes, constraint changes, unit trips—within minutes.
The reality: AI and advanced optimisation software aren’t add‑ons anymore; they’re the engine of revenue. This is where the green technology theme really shows up: clean hardware only reaches its potential when paired with intelligent control.
How 15-Minute Markets Change Battery Business Models
The shift to 15‑minute trading doesn’t just tweak revenues. It nudges the whole battery business model toward more active, software‑driven operation.
1. From static to dynamic revenue stacking
With more granular pricing, a BESS can:
- Arbitrage day‑ahead price differences at 15‑minute resolution.
- Chase intraday volatility as forecast errors in wind/solar are corrected.
- Provide fast frequency and balancing services when prices spike.
This naturally leads to dynamic revenue stacking, where the asset constantly re‑optimises between:
- Arbitrage
- Reserve and balancing markets
- Capacity and reliability schemes
- Corporate PPAs or tolling agreements
One good example is the 20MW/40MWh project in Germany under a tolling agreement between Shell‑owned Next Kraftwerke and ju:niz Energy. In a 15‑minute world, these kinds of structured deals increasingly depend on the optimisation stack: how you dispatch the battery across multiple products is as important as the hardware itself.
2. More upside, but more risk concentration
Shorter intervals magnify both:
- Upside from volatility
- Risk of missing or mis‑positioning around price spikes
Day‑ahead arbitrage values also have to be adjusted for real‑world factors:
- Efficiency losses through round‑trips
- BESS availability and degradation constraints
- Market liquidity in specific intervals
- Hedging strategies that may cap exposure to extreme prices
Investors should be honest about this: chasing every spike can destroy batteries quickly and create ugly tail risks. The smart approach is risk‑aware optimisation—moderate cycling, robust hedging, and revenue floors, combined with algorithmic capture of high‑value periods.
3. Software and AI as value multipliers
In a 24‑interval world, you could get away with heuristic or even spreadsheet‑driven strategies. In a 96‑interval (or 288‑interval) world, you’re leaving double‑digit value on the table without proper tooling.
Effective BESS optimisation in 15‑minute markets typically includes:
- Machine learning forecasts for prices, renewables, load and congestion.
- Stochastic optimisation that runs thousands of future scenarios and picks dispatch plans that maximise expected value given risk constraints.
- Automated bidding agents plugged into market APIs, executing strategies continuously rather than in day‑ahead “set and forget” mode.
This is exactly where AI and green technology intersect: the physical asset cuts emissions by storing and shifting clean energy; the AI layer makes that asset profitable enough to scale.
Practical Moves for Developers, Investors and Corporates
Here’s how different players can use 15‑minute trading to their advantage.
For BESS developers
- Rebuild your financial models. Use 15‑minute historical price series, not hourly, and stress‑test arbitrage under long‑term assumptions (for example, Rystad’s US$60/MWh average instead of today’s US$150/MWh).
- Design for smart dispatch. Size inverters, EMS and communication so the asset can respond quickly to quarter‑hour intervals and grid signals.
- Plan for software from day one. Treat the optimiser like a core system, not a late procurement item. Contracts that share upside with optimisation providers can align incentives.
For investors
- Underwrite the optimiser, not just the asset. Two 50MW batteries in the same node can have very different cashflows depending on their optimisation algorithms, data quality and risk policies.
- Ask for realistic, risk‑adjusted cases. Look beyond perfect‑foresight backtests. Demand sensitivity analyses for efficiency losses, limit constraints, and declining volatility.
- Recognise the structural uplift. A roughly 3% ROI improvement over 20 years from market design is fundamentally different from a temporary policy subsidy. Price that into your view of the asset class.
For corporates and energy buyers
- Think beyond static PPAs. Structuring tolling arrangements or flexible offtake deals around optimised batteries can lower your energy cost while improving grid flexibility.
- Use storage to manage volatility exposure. As prices become more granular and spiky, co‑located or contracted storage becomes a natural hedge.
- Align with your net‑zero strategy. Batteries earning money by smoothing renewables volatility are doing double duty: supporting your decarbonisation goals and protecting your energy budget.
The Bigger Picture: AI, Markets and the Next Phase of Green Tech
Zooming out, 15‑minute power markets in Europe are part of a bigger pattern we keep seeing across this green technology series:
- Hardware (solar, wind, batteries, EVs) is already cheap and scalable.
- The constraint is intelligence: how we orchestrate millions of distributed assets across time and space.
- Market design is catching up—by valuing flexibility in higher resolution and rewarding fast, smart responses.
As more European countries adopt 15‑minute settlement—and potentially move to even finer resolutions over time—the share of value created by AI, forecasting and optimisation will only grow.
For storage specifically, here’s the bottom line:
In a 96‑interval day, batteries that are optimised by AI will consistently outperform those that aren’t—and over a 20‑year life, that gap compounds into a material ROI difference.
If you’re building or financing energy storage in Europe right now, the question isn’t whether 15‑minute trading matters. It’s how quickly you can redesign your strategy, your models and your tech stack around it.
Those who treat this as a core part of their business model—not a regulatory footnote—will be the ones still standing when we look back at this moment as the point where flexible, AI‑enabled storage became a cornerstone of Europe’s clean energy system.