Battery feasibility analysis tests the economic logic of adding energy storage (BESS) to existing or planned solar power through an hourly production–consumption profile. After May 1, 2026, the period of "using the network as a free battery" in hourly settlement has ended; While the excess energy produced at noon goes to the grid with a low PTF, it is purchased at a high tariff during peak hours in the evening. Storage Solar Energy solves this hourly discrepancy at the facility, increasing the self-consumption rate and storing the energy that would be lost free of charge in case of exceeding the 2× chargeable limit.
Why is storage solar power on the agenda?
As detailed in our BESS After Hourly Settlement guide, in a typical industry profile, there is a serious gap between the unit cost of purchasing from the grid and the excess solar sales revenue. The payback period of solar power without storage may extend to 12–18 months. The rationale for battery investment should not be “arbitrage sale to the market” — the payment mechanism for energy delivered from storage to the grid is limited by regulation in the unlicensed segment — but “reducing expensive purchases from the grid” and “increasing self-consumption”. Our Battery Feasibility Analysis tool tests this scenario with hourly simulation.
720 hours/month
Hourly equalization
Profile compatibility is critical
peak shaving
BESS main value
Peak clock substitution
grant energy
2× limit protection
Keep excess production on site
How to do battery feasibility analysis?
The form on the /battery-feasibility page uses the same consumption models as the SPP feasibility form (Mode 1 annual summary, Mode 2 monthly+daytime %, Mode 3 hourly Excel). The switchboard location is selected from the map; Installed power (kWp), tariff, power plant type (5.1h/5.1c) and consumption profile are entered. On the battery side, capacity (kWh), charge/discharge C-rate, investment amount (TL) and charging strategy are defined: only solar charging (solar_only) or grid charging options are available. The analysis result can be downloaded as PDF and Word.
Form entries — battery parameters
| Parameter | What does it do? | Typical value |
|---|---|---|
| Capacity (kWh) | Stored energy ceiling | According to daily excess production |
| Charging C-rate | Max charging power per hour | 0.5C common |
| Discharge C-rate | Max discharge power per hour | 0.5C common |
| Investment (TL) | CAPEX — reimbursement account | Quote/EPC price |
| Charging strategy | Güneş only vs grid | solar_only priority |
| Hourly consumption (Mode 3) | Settlement simulation | OSOS export |
The role of the battery in hourly settlement
In hourly settlement, each hour's production is matched only by that hour's consumption. The battery produces value through three mechanisms: (1) Load shifting — shifting excess production at noon to the evening shift; increases the offset rate. (2) Peak shaving — reducing grid draw during peak hours; Reduces high unit cost purchasing. (3) 2× limit protection — prevents the loss of free YEKDEM by keeping excess production approaching the paid ceiling in the warehouse. The financial spread table in our Hourly Settlement 2026 guide shows the difference between the no-storage vs. with-storage scenario.
Storage Solar Energy regulation notes
The end-2025 regulations clarified the separate monitoring of energy stored in the YEKTOB account and integrated storage price categories for RES/SPP with storage. Integrated storage in unlicensed production facilities should be evaluated together with the technical specifications and EPİAŞ LUM records. During the feasibility phase, regulation compliance should also include the costs of connection to CAPEX and fire/transformer capacity.
Checklist on ROI calculation
- Hourly consumption-production overlap rate (% current offset)
- Net network purchase during peak hours (kWh and TL/year)
- Average daily excess production vs battery capacity (kWh)
- Round-trip efficiency loss (85–90% band typical)
- 2× limit projection — free loss without storage (kWh)
- Battery CAPEX and warranty cycle (years)
- Additional cost/revenue balance if grid charging allowed
Solar feasibility + battery: together or separately?
Optional battery areas are also available in the SPP feasibility form for new SPP investments — a SPP+BESS scenario can be produced in a single report. If a battery is added to the solar power plant in the existing operation, the Battery Feasibility Analysis tool is more focused; current kWp and actual OSOS profile are loaded with Mode 3. In both cases, demand management in our Contract Power and Peak Load guide provides cross-checking on battery sizing.
Who should have a battery feasibility assessment?
- Industry with heavy production at noon and heavy consumption in the evening/night profile
- High kWp rooftop solar power approaching or exceeding the 2× limit
- Commercial premises and OIZ tenants with high peak tariff differences
- Storage-free solar energy investors with extended ROI after hourly settlement
- Facilities experiencing demand penalties and contract power exceedance (peak shaving)
Conclusion
Battery feasibility analysis asks whether solar energy investment still makes sense without storage during the hourly offset period. gives a numerical answer to the question. The correct input is the hourly consumption profile and realistic CAPEX; BESS ROI cannot be calculated with kWp × yield alone. The ENOPTIMAL Battery Feasibility Analysis tool runs this simulation for free; After commissioning, the SPP production monitoring module verifies the projection with real inverter and OSOS data. The new investment scenario is detailed in our SPP feasibility report guide, and the limit and revenue model are detailed in our unlicensed SPP energy sales guide.