We split the review into five phases of the project life cycle and four cross-cutting modules (budget, investment case, ownership, subsidies). Every output has a consistent structure and a clear traffic light.
Two depth levels
You choose the depth based on the decision stage. Quick check (Light DD) is a fast red/green check for go/no-go — it contains only the Quick check, Critical findings and a snapshot of the investment recommendation and rights. Full DD goes into all phases and modules: each phase has introduction → narrative → Checklist table → Critical findings → Quick check.
🟢 compliant🟡 conditional🔴 critical finding⚪ out of scope
Five phases
The whole project life cycle — phases 0–5, milestones, the LV vs. MV/HV timeline and the buyer's entry points — is on one process map on the page
How we do it. What follows here is a description of the individual phases of the review.
PHASE 1
Pre-development and feasibility study
Project viability before a major investment.
Project and site definition · subsoil (geotechnics, corrosivity) · environment and biodiversity (Natura 2000) · permitting (competent authority: 22/35 kV → municipal building office, 110 kV → regional building office, 220/400 kV transmission → the specialised authority) · archaeology and UXO · land and stakeholders · grid connection (connection point, voltage level, reserved capacity, RfG category, connection agreement, EMS limit, metering point ID) · costs and schedule.
PHASE 2
Contracting
Technical-commercial review of contracts.
EPC (scope, guarantees, risk allocation) · O&M (≥ 98 % availability) · supply (supplier bankability, IEC / UL 9540A certification, FAT) · PPA (price, volume, profile).
PHASE 3
Financing and bankability
Risk quantification and compliance with EU regulation.
Risk register (FMEA → RPN) · sensitivity (P50 / P75 / P90) · merchant vs. contracted revenue · governance and cybersecurity (CSRD, NIS2).
PHASE 4
Construction and commissioning
Quality of execution.
QA/QC (ITP, hidden defects) · commissioning and as-built · LV/MV interface.
PHASE 5
Operation and maintenance
Performance over the asset lifetime.
KPIs (availability, yield, efficiency) · degradation and FMEA · firmware and cybersecurity. Optionally revamping, brownfield acquisition, decommissioning.
Four modules
M1 · Budget and schedule
A CAPEX cost benchmark (solar €/Wp, BESS €/kWh, PCS €/kW, EPC/BOP, Devex €/MW) against the market; schedule from building permit through connection approval and final inspection to CoD.
M2 · Investment case (DCF)
Price structure (Devex / Capex / Opex / financing) → NPV, IRR (leveraged and unleveraged), simple payback, DSCR, the maximum justifiable purchase price.
M3 · Ownership and maturity
Rights to land, the substation and the cable route; Share vs. Asset transaction structure; stakeholder map; maturity stage Early / RTB / NTP / CoD.
M4 · Subsidies
Modernisation Fund / RES+ (SFŽP), OP TAK — eligibility and impact on economics.
Revenue stack — how the battery earns
A business case doesn't rest on a single revenue. We review the whole stack: reservation of balancing services (capacity held for ČEPS), activation (delivered balancing energy), arbitrage on the day-ahead market (buy low / sell high), intraday trading and distribution-fee savings (ITS) for behind-the-meter projects. The share of each stream varies by topology (behind-the-meter vs. in-front-of-meter) and is key to payback resilience.
Distribution fees (ITS) — LV / MV / MV
For behind-the-meter projects distribution charges are a direct saving (part of the revenue stack); for utility projects they are a significant cost. They are governed by the annual annual ERÚ price bulletins (separate decisions for LV and MV/MV). The regulated component consists of the price for distribution, system services, non-network infrastructure (EDC + OTE + ERÚ) and a contribution to renewable support levy.
- POZE = CZK 0/MWh from 1 Jan 2026. The government moved the funding of supported sources fully onto the state (previously CZK 495/MWh for households) — a significant drop in the regulated component, which we include in the model.
- MV / MV: a reserved-capacity charge (CZK/MW/month) + a network-use charge (CZK/MWh). The system charges the lower of T1/T2; a Pmax discount by round-trip efficiency (MV threshold 0.60 / 0.75; RTE ≥ 0.75 → Pmax = 0).
- LV: breaker-linked components (CZK/A/month) + CZK/MWh by distribution tariff.
- Transformation losses (metering on the secondary side): max 2 % MV, 4 % MV.
- From 1 Jan 2027 a new tariff structure (NTS) for MV/MV — key for BESS. It abolishes the reserved-capacity charge and replaces it with a two-part fixed fee: a reserved-input charge (not charged until now) + a maximum-drawn-power charge (the highest 15-minute peak in the month). The centre of gravity of payments shifts from MWh to input and peaks → a direct incentive for storage and peak-shaving. Relief for batteries: A MV BESS with site efficiency ≥ 75 % gets a 100 % discount on the maximum-drawn-power component. LV is not yet affected (pilot 2028, wider rollout from 2030).
The platform pulls concrete values from ERÚ price bulletins per DSO (ČEZ D, EG.D, PRE, LDS) — we don't infer from memory.
Community energy and sharing
Electricity sharing (Lex OZE II, from 1 Jan 2024; Lex OZE III added customer protection, storage and aggregation) changes the business case especially for homes, companies and municipalities. Electricity generated in one place can be consumed elsewhere — virtually, via the distribution grid. There are two routes:
| Regime | Members (EAN) | Territory | Registration |
|---|
| Active customer | up to 11 | all of Czechia | EDC only (free) |
| Energy community | up to 1,000 | until 1 Jul 2026 max. 3 adjacent ORP districts | EDC + ERÚ (non-profit entity) |
- An economic impact we must not overlook: with sharing via the distribution grid the supply is billed taking sharing into account, but you still pay the distribution-grid service (the regulated per-MWh component) even for shared electricity. So the saving arises on the energy component, not on distribution.
- Technical condition: interval (AMM) metering at all consumption points — installed free by the DSO after EDC registration.
- Sharing group: allocation key (static, iteration only up to 50 EAN); up to 5 generating EAN per consumption EAN, priorities 1–5; each EAN in one group only.
- Link to subsidies: from 2025, joining sharing is a condition for a higher NZÚ PV subsidy (up to CZK 140,000 vs. CZK 100,000).
- Outlook: full EDC operation in H2 2026 opens storage, flexibility and aggregation — further battery monetisation.
Principles we hold
- Scenarios, not a single number. We always present economics in low / base / high variants — the market is volatile and a single value misleads.
- DSCR < 1.2 = sub-threshold. Minimum annual debt-service coverage below 1.2 is always flagged as sub-threshold (not bankable without restructuring).
- Breakeven is computed from the full DCF, not from an indicative sensitivity — so the verdict often stands or falls on the annual average arbitrage spread, not a seasonal sample.
- We distinguish contracted vs. recommended and Share vs. Asset deal — risk and price look different.
- Market data from source. Reservation prices (ČEPS/ALPACA), activation (PICASSO/MARI), day-ahead (OTE) and CAPEX are taken from real data, not from memory.
The methodology is the basis for the automatically generated outputs (one-pager, Quick check (Light DD), Full DD) and for the human review of acquisitions. The outputs carry the label “bessaudit.com by Sun.Energy Holding s.r.o.” and do not constitute legal, investment or tax advice.
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