Section 1 — Project Basics

Country required

Technology

Renewable Capacity (MW)

Capacity Factor (%) editable

Default: 18% solar / 35% wind

Offtake Structure

Merchant (no PPA)

Full cannibalisation exposure

Fixed-price PPA

Cannibalisation defence = €0

Section 2 — BESS Sizing

Auto-size BESS for my project

Tool recommends MW/MWh based on technology and capture rate

I want to size it myself

Enter BESS power and duration below

Battery Chemistry pre-fills CAPEX & RTE

LFP — Dominant utility-scale choice. Best cycle life, thermally safe. €350/kWh · 85% RTE · 6,000 cycle life.

BESS CAPEX (€/kWh)

BNEF Q4 2025 European reference

BESS OPEX (€/kWh/yr)

Round-trip Efficiency (%)

Cycles/day cap

Conservative: 1.0 / High-utilisation: 1.5–2.0

WACC (%)

Project Lifetime

25 yr renewable / 10 yr BESS warranty

BESS replaced once at year 12 at 50% of original CAPEX (cost decline assumption). BESS capacity degrades 2%/yr (NREL 2024).

BESS WACC premium (bps)

Added to renewable WACC for BESS portion. Default: +200 bps (2pp).

Include ancillary revenue estimate (€15-30/kW/yr)

Conservative estimate for FCR/aFRR. NOT included in NPV by default.

10 credits per screen (€50) · results in ~10 sec