July 13, 2026
Day-ahead optimization
Published by
Olaf Ketelaars
Covolt Netherlands
A battery system is only truly valuable if it charges and discharges at the right time—not just any time, but precisely when conditions are most favorable. That’s exactly what day-ahead optimization does: every day, Covolt calculates the optimal charging and discharging schedule for your battery based on tomorrow’s energy prices.
What is day-ahead optimization?
The day-ahead market is the energy market where electricity is traded for delivery the following day. Every afternoon, the EPEX exchange publishes the prices per quarter-hour for the following day. These prices vary widely: they are low at night and during the day when there is plenty of solar energy; at peak times, they can be significantly higher.
Day-ahead optimization takes advantage of these price differences: charge the battery when electricity is cheap, and discharge it when electricity is expensive.
How does it work in practice?
Retrieve price data
Covolt connects daily to the official EPEX MATS API to retrieve the current day-ahead prices. As soon as the prices for the following day are known, the optimization algorithm gets to work.
Calculate the optimal charging schedule
The algorithm calculates which charging and discharging times yield the highest return, taking into account:
- The price curve for the following day
- The energy profile and consumption pattern of your connection
- Transmission costs; for connections with high transmission rates, it may be more cost-effective to strategically spread out battery cycles
- The maximum number of daily cycles for your battery
- The connection limits for your location
Control via the Covolt Control Box
The calculated schedule is automatically executed on-site via the Covolt Control Box.
What are the benefits?
Day-ahead optimization generates returns by arbitraging daily fluctuations in electricity prices. In addition to direct revenue, the strategy can also reduce transmission costs by smoothing out consumption peaks. We also store any solar power generated in the battery to discharge it when prices are high.
Day-Ahead Trading vs. Imbalance Trading
| Day-ahead optimization | Imbalance trading | |
| Pricing Basis | EPEX day-ahead (announced the day before) | Imbalance Price (Real-Time) |
| Predictability | High | Lower |
| Risk | Low | Higher |
| Suitable for | Stable, predictable optimization | Actively Responding to Volatility |
What can Covolt do for you?
- Covolt automatically retrieves the current EPEX day-ahead prices every day.
- The algorithm calculates the ideal charging and discharging schedule for your battery.
- The Covolt Control Box automatically executes the schedule on-site.
- Covolt takes your energy profile, transportation costs, and connection limits into account.
- Through the Covolt myHorizon app, you can view the day-ahead strategy and the revenue generated.
Learn more?
Would you like to know what Covolt can do for your assets? Contact us or schedule a no-obligation consultation.
Find out what else we cando for you
Together with you, we determine the required combination of services that fit your specific needs and goals. Regardless of whether you are, for example, an agriculturist or a large property manager.
