Investing in BESS in Ukraine: how to test the project and its financial model
Test a Ukrainian BESS investment against usable capacity, grid rights, market access, realistic dispatch, losses, degradation and lifecycle funding needs.
Jurisdiction: Ukraine. Sources reviewed . Periodic review required. Next scheduled editorial review: . Material rule changes require earlier review.
A battery project is investable only if its technical limits, grid rights, market access and operating plan support the same revenue model. A spreadsheet listing several possible income streams is not enough.
A battery energy storage system, or BESS, buys or receives electricity, stores it and releases it later. Its value depends on when it can operate, how much energy it can deliver and the costs and obligations attached to that operation.
Start with the usable system
Power in megawatts (MW) tells you how fast the battery can charge or discharge. Energy capacity in megawatt-hours (MWh) tells you how much it can store or deliver under a stated measurement basis.
Ask whether the quoted MWh is nominal cell capacity or usable energy at the delivery point. Confirm the starting state of health, operating temperature, permitted depth of discharge, auxiliary consumption and warranty limits. State of health describes the battery’s condition relative to its specified starting performance.
A nominal 20 MW / 40 MWh system suggests two hours at full power by simple division. It does not establish two hours of net export under every operating condition. The equipment rating, usable energy and connection limit may each constrain delivery.
Check the legal and grid configuration together
Article 30-1 of the Electricity Market Law addresses storage operators, licensing, permitted grid flows and separate commercial metering. The text checked on 25 September 2026 expressly refers to licensing where installed storage power on one metering site exceeds 5 MW. It also distinguishes installed power from the capacity requested or permitted at the grid connection.
Do not turn that threshold into a blanket statement that every smaller or co-located installation is free of regulatory requirements. Establish the operator’s role, applicable exception, current licensing conditions and actual metering configuration. A generation licence should not be assumed to resolve every storage activity.
For a co-located battery, identify who owns the electricity at each stage, which meter measures it, and which contract governs its sale. Test combined solar and battery operation against the shared import and export limits.
Prove each revenue stream separately
Table — scroll horizontally if needed
| Proposed income | Evidence needed | Main question |
|---|---|---|
| Buying low and selling high | Interval prices, feasible dispatch and all purchase and sale costs | Is the spread still positive after losses and charges? |
| Balancing services | Applicable participation arrangements, technical capability and settlement terms | Can the project deliver the required response? |
| Ancillary services | Evidence of required qualification and the actual award or contract, where relevant | Is revenue contracted, available for competition, or only assumed? |
| Customer services | A defined customer benefit and enforceable payment terms | Who pays, and for which measured service? |
Legal permission to participate is not evidence that a specific battery is qualified, has won a contract or will be dispatched. Until those steps are supported, model the revenue at its actual stage of certainty.
Do not sell the same capacity twice in the model
If capacity is reserved to provide a service, it may not be available for unrestricted energy trading at the same time. Reserved upward and downward response can also require energy headroom in the battery.
Build a dispatch schedule at the time resolution relevant to the market and contracts. Track charging, discharging, reserved capacity, stored energy, outages and limits. Revenue streams can be combined only where the actual rules and operating constraints allow it.
The model should also test imperfect price forecasts. A backtest that selects the cheapest and most expensive intervals after seeing the entire price series overstates what an operator knew when making decisions.
Check the margin after losses
Consider an invented single-cycle example. The battery purchases 10 MWh at €60/MWh, costing €600. At an assumed 85% round-trip efficiency, it delivers 8.5 MWh. Selling at €120/MWh earns €1,020, leaving €420 before all other charges and costs.
The example uses euros only for readability, excludes value-added tax and is not a Ukrainian market price forecast. It leaves out network and market charges, service-provider fees, imbalance costs, degradation, fixed operating costs and tax. A €60/MWh headline spread is therefore not a €600 net profit on that cycle.
Have the applicable network-charge treatment checked for the project’s configuration and period. The retrieved Article 30-1 contains transitional wording on charges. A single generic charging assumption should not be copied into every BESS model.
Fund the whole operating life
Allow for degradation, augmentation or replacement, maintenance, software and control services, insurance, site costs and end-of-life obligations. Augmentation means adding capacity to restore or maintain performance as the original batteries age.
Test the manufacturer’s warranty against the proposed use. Compare throughput, cycles, temperature and availability commitments. A warranty limited by operating conditions may not support an aggressive revenue schedule.
Run downside cases for delayed connection, lower spreads, reduced service income, worse efficiency, lower availability and earlier augmentation. Include the cash needed for collateral, payment timing and construction overruns. A high projected return does not solve a funding shortfall.
Financial-model diligence: inputs to challenge
Ask for one auditable model with an assumptions register, dispatch calculation, income reconciliation, capital schedule and financing waterfall. Trace each material input to a source and date. Keep formula changes visible; a seller's output-only spreadsheet cannot show whether constraints were applied consistently.
Table — scroll horizontally if needed
| Input | Evidence / test | Downside to run |
|---|---|---|
| Usable power and energy | Measurement boundary, operating range and year-specific capacity | Lower retention and service duration |
| Grid | Separate import/export, shared headroom and completed scope | Reduced import and delayed energisation |
| Revenue | Award/contract status, settlement formula and dispatch compatibility | Remove unawarded service revenue |
| Prices | Interval series, forecast methodology and feasible bidding | Weaker spreads and imperfect forecasting |
| Costs | Charging, losses, network treatment, BRP/aggregator, imbalance and fixed operations | Higher costs and collateral |
| Lifecycle | Throughput limits, availability, augmentation scope and funding | Earlier intervention and downtime |
| Cash and financing | Collections, tax assumptions, debt service and equity timing | Payment delay and peak cash deficit |
Check units, sign conventions, real/nominal prices, inflation, currency and tax treatment consistently. Reconcile monthly results to the annual cash flow; test that changing an input changes dispatch where appropriate, not only the reported return. Do not assume a promised service and an unconstrained trading case can coexist.
Record which assumptions have been reviewed by a specialist and the scope of that work. The model is a forecast; its result is not a generic Ukrainian BESS IRR or a recommendation to invest.
Your next step
State the BESS configuration, grid limits and revenue evidence you require. Share your investment criteria with Tillerstone to focus the search on projects you can assess meaningfully.
Legal sources checked through Mitralex on 25 September 2026. The numerical example is synthetic. Detailed licensing, service-qualification and charging treatment must be confirmed for the individual project and period.