Our model battery generated PLN 39.7k in December from DA + IDC optimization. This result is close to December 2024 (PLN 49.1k), but 20% lower year over year.

After two full years of data, we can now talk about clear seasonality in BESS revenues

• Best period: May to September – consistently high earnings (over PLN 75k/month)
• Noticeable declines: in Q4 and in January–February
• Market signal: seasonality correlates with PV generation, but also with higher volatility in the DA and ID markets in the warmer months

December closes out a weaker Q4 - average monthly revenues in Q4 2025 were PLN 55.9k, i.e., 23% lower than in Q3.

Tell us what you think!

💬 Will this pattern hold in 2026? Or will the growing supply of energy storage and flexible gas-fired sources change the seasonality dynamics? Let me know in the comments!

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December 2025 – in line with the seasonal trend

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