BESS · Feasibility & grid-scale storage · Turkey
Battery Energy Storage (BESS) Advisory
Oztoprak Energy provides independent BESS advisory covering feasibility studies, optimum MW/MWh capacity sizing, battery integration with HEPP and solar plants, revenue optimization, and technical due diligence — for investors and plant owners evaluating storage additions to existing generation assets in Turkey.
Technical Scope
BESS Feasibility and Optimum Capacity Sizing
Technical and economic feasibility assessment before a battery investment decision. Sizing considers MW (power) and MWh (energy capacity) together, aiming for the capacity range that best supports investment returns rather than the largest possible battery.
BESS Technical Due Diligence
Pre-investment review of battery storage projects — cell chemistry selection, degradation modelling, PCS efficiency, BMS capability, fire protection, and site integration risk.
Grid Compliance Review
Assessment of BESS grid connection requirements under TEİAŞ rules — FRT capability, protection coordination, reactive power mode, black start readiness, and frequency response.
EPC Scope and Performance Guarantee Review
Independent review of BESS EPC contracts — RTE efficiency guarantees, degradation allowance, availability warranties, FAT/SAT procedures, and commissioning test criteria.
BESS from an Investment Perspective
A battery energy storage system (BESS) stores electricity and releases it later, which can change how a generation asset earns revenue and manages grid constraints. Whether that is worthwhile depends on the specific plant, its connection, its production profile and the market conditions it operates in. For an investor the useful question is therefore not whether to install a battery, but under which technical and economic assumptions a given size makes sense, and what must be verified before committing capital.
Our Engineering Evaluation Framework
Each BESS engagement is built around the topics below. They describe what is reviewed, not typical results: capacities, efficiencies, costs and returns are determined project by project from the plant's own data and current supplier documentation.
Power-to-energy ratio and storage duration
MW and MWh are sized together. Storage duration (hours at rated power) is a design variable derived from the plant's production profile, grid limits and the intended use of the battery, not a fixed value.
PCS selection
Power rating, reactive power capability, grid-code compliance, efficiency across the operating range, thermal derating, and AC- versus DC-coupling for the specific plant.
Battery container configuration
DC block sizing, cooling and thermal management, fire protection, layout and access, and conformity with the applicable standards and permitting requirements.
Transformer and grid connection
Connection point and voltage level, transformer sizing, protection coordination and the effect of the battery on fault levels at the point of connection.
Short-circuit and grid constraints
Short-circuit contribution, fault ride-through behaviour, export and import limits and the operator's technical requirements, checked before capacity is fixed.
Degradation and augmentation
Capacity fade assumptions taken from supplier data and tested against the planned cycling regime, with an augmentation or replacement strategy reflected in the model.
Round-trip efficiency and availability
Efficiency is only comparable when the measurement boundary is defined (for example at the point of connection, including auxiliaries). Availability definitions and exclusions are reviewed in the contract.
CAPEX and OPEX assessment
Cost items (battery, PCS, balance of plant, EPC, grid connection, O&M, augmentation, insurance) are compared on a like-for-like basis using current quotations, never generic benchmarks.
Technical specification and bid evaluation
Specification drafting and technical comparison of EPC and vendor offers: scope gaps, interfaces, performance guarantees, test procedures (FAT/SAT), warranty exclusions and liability terms.
Optimum MWh Sizing Approach
A plant's historical production data and market price data can be analyzed to compare different BESS capacity scenarios — for example, illustrative candidates such as 5 MWh, 10 MWh, 15 MWh or 20 MWh. This is not a fixed methodology or a mandatory step size applied to every project; the optimization resolution can vary depending on the project's characteristics, data availability, and objectives. The goal is not to select the largest possible battery, but to identify the BESS size that best supports investment returns.
MW ≠ MWh
MW describes power — how fast the battery can charge or discharge. MWh describes energy capacity — how much energy it can store. A sound BESS sizing exercise treats these as two separate, jointly optimized parameters, alongside efficiency, degradation, SoC/DoD limits, and cycle life.
HEPP + BESS Integration
For hydropower plants, BESS integration is evaluated against the plant's own production variability and the value of shifting output to higher-price hours, within the plant's operating and connection constraints.
HEPP production profile and hydrological variability
Hourly production vs. market price alignment
Charging in low-price hours, discharging in higher-value hours
Plant operating constraints and connection capacity limits
Turbine/generator operating characteristics alongside BESS response
BESS power-to-energy (MW/MWh) ratio optimization
Cycle optimization and degradation impact on long-term revenue
Solar + BESS Integration
For solar plants, BESS is typically evaluated in relation to the production curve, curtailment exposure, and the opportunity to shift solar output into higher-value hours.
Solar production curve and peak-shifting potential
Curtailment assessment and energy-shifting opportunity
Connection capacity and co-location constraints
BESS sizing relative to installed solar capacity
Charge/discharge strategy optimization
Investment return analysis for the combined GES+BESS asset
HEPP+BESS is one of our main commercial priorities, but BESS advisory is not limited to hydropower — solar and other generation assets are evaluated on the same basis.
BESS Revenue Optimization
Equipment cost alone is not a sufficient basis for a BESS investment decision. Where suitable, the evaluation model can be described as follows:
This process does not produce a guaranteed revenue figure or a guaranteed return rate. It compares scenarios so that a capacity decision can be made on an informed basis.
Project-Specific Analysis and Optimization Approach
Proje özelinde geliştirilen analiz ve optimizasyon modelleri ile farklı BESS güç ve enerji kapasitesi senaryoları karşılaştırılabilir. This is a project-specific advisory approach, not a ready-made commercial software product.
Model inputs
Production time series
Electricity price time series
MW and MWh candidates
Round-trip efficiency
SoC limits and DoD
Cycle constraints and degradation
CAPEX and OPEX
Outputs
Suitable capacity scenarios
Estimated energy-shifting volume
Indicative revenue impact
Cycling behavior
Battery utilization rate
Investment return indicators
BESS Pre-Feasibility Study
Potential scope — the actual scope of an engagement is shaped by the project's specific needs, not applied identically to every project:
- 1
Data collection
- 2
Production profile analysis
- 3
Market price analysis
- 4
Identification of technical constraints
- 5
MW / MWh scenarios
- 6
Charge/discharge simulation
- 7
Degradation impact
- 8
Revenue analysis
- 9
CAPEX / OPEX assessment
- 10
Financial scenario analysis
- 11
Recommended BESS capacity range
- 12
Technical and economic summary report
Technical topics we cover
Lithium-ion chemistry selection: LFP vs NMC for utility-scale storage
BESS degradation modelling and capacity warranty evaluation
Power Conversion System (PCS) grid interface and harmonic compliance
Battery Management System (BMS) protection and communication protocols
TEİAŞ grid code compliance for large BESS facilities
BESS co-location with solar — control strategy and grid connection impact
Fire suppression system adequacy and IEC 62933 compliance
Revenue stacking strategies: frequency regulation, arbitrage, capacity
BESS lender's engineer scope for project finance
Operational KPI framework and O&M contract adequacy
Related services
Market context — Turkey BESS
Turkey's BESS market is being shaped by YEKA storage tenders, ancillary service market reforms, and co-location requirements for large renewable plants. TEİAŞ grid code requirements for battery storage are still developing — projects procured today will need to meet evolving compliance obligations through their operating life.
A BESS addition's potential effect on a plant's revenue profile and economic value can be assessed on a scenario basis, project by project — this is not a guaranteed increase in plant value.
Ready to identify what is limiting your plant's performance?
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