Decision-making toolkit

Capital expenditure modelling

Capital cost built up from the design itself, not scaled off a benchmark. Change the foundation, the turbine or the water depth and watch the whole estimate move.

Overview

What CAPEX does

A deterministic, parameter-level model for wind farm construction. Covering seven clear chapters, every input is visible. There are no hidden sheets or locked formulas, ensuring complete transparency and traceability.

Variables such as soil profiles, turbine ratings, and array layouts are intrinsically linked. Adjust one parameter, and the model instantly recalculates steel tonnage, vessel requirements, and installation schedules, revealing the commercial impact of every engineering decision in real time.

Full parameterisation makes evaluating alternatives effortless. Duplicate, edit, and compare saved scenarios to transform static cost estimation into a dynamic, informed optioneering process.

Live · Demonstration project

£1,196m

Total capital cost, expected case

By componentOptimistic to pessimistic

Eleven components, and a range of £962m to £1,435m

Top features

What you get with CAPEX

  1. Assumptions in chapters

    Every input is a clearly labelled assumption with a unit, validation and an audit history. Easily track completion status and gain an instant overview of project scenarios.

  2. Scenario management

    Name a scenario, duplicate it, change parameters then run the costings. Compare scenarios and clearly track all changes, so the reasons for change live clearly in the project.

  3. Library-backed inputs

    Turbines, foundations, vessels, cable costs and contingency factors are selected from a shared library rather than typed. Technical specifications are from shared records and can be locked, so the model never disagrees with defined assumptions.

  4. Derived values, computed not copied

    Parameters that follow from others are marked as derived and recompute when their source changes. The interface shows you which is which, so nobody spends an afternoon overwriting a value the model was always going to recalculate.

  5. A change history you can defend

    Every edit is recorded — what changed, from what, by whom and when. When an estimate is challenged six months later, the answer is a record rather than a recollection.

  6. Board-ready results

    Cost breakdowns by category, package and year, exportable to Excel and PowerPoint — making board packs and reports always based on the model, rather than being retyped or pasted.

Illustrative examples

CAPEX in use

Drawn in the product's own interface, and every figure is real: they come from our live Demonstration project — a 288.75 MW floating wind farm in the central North Sea — and its Default Scenario, so anything shown here can be reproduced in front of you. No client or commercial data appears on this page.

Illustrative

The input form, as you would actually meet it

The Foundation and wind turbine chapter of the Default Scenario. Three navigation tiers — the project and scenario pickers across the top, the module rail down the left, the chapter bar above the form — and then the inputs: a grid of cells, each carrying where its value came from.

Project Demonstration project Scenario Default Scenario Project team
Foundation and wind turbine Environmental conditions Economic and general Wind farm T&I Wind loader Energy yield
DTA Suggest Role focus (all fields)

Foundation and wind turbine

19 of 19 fields answered

Foundation

Foundation Type * Semi-sub 3C

Custom source – Foundations

Share of Steel on Primary Mass * 0 %

Share of Concrete on Primary Mass * 100 %

FOU Fabricator * Europa

WTG

WTG Model * Generic Direct Drive 11.55MW

Custom source – Turbines (WTG) Was SGRE DD-220

Wind Farm Type * Floating

Rated Power * 11.55 MW

Custom source – Turbines (WTG)

Rated Wind Speed * 16 m/s

Custom source – Turbines (WTG) Was 10.60 m/s

Cut-in Wind Speed * 3 m/s

Custom source – Turbines (WTG)

Cut-out Wind Speed * 28 m/s

Custom source – Turbines (WTG) Was 25.00 m/s

Rotor Diameter * 236 m

Was 120.0 m Not set on Generic Direct Drive 11.55MW (add it)

Hub Height * 150 m

Was 90.0 m Not set on Generic Direct Drive 11.55MW (add it)

Max. NSS Tower Base Moment * 311,150 kNm

Custom source – Turbines (WTG)

WTG Fabricator * Europa

Custom source – Turbines (WTG)

Drivetrain * Direct Drive

Not set on Generic Direct Drive 11.55MW (add it)

Control * Pitch Regulation

Not set on Generic Direct Drive 11.55MW (add it)

IEC Class * 1B

Not set on Generic Direct Drive 11.55MW (add it)

WTG Mass * 1,800 t

Was 435.0 t Not set on Generic Direct Drive 11.55MW (add it)

Tower Mass * 1,500 t

Custom source – Turbines (WTG) Was 815.1 t

The bar down the left of a cell is its state, in a shape as well as a tint: violet for a value the shared library owns, teal for one this scenario has changed. "Was 120.0 m" is what the parameter held before the edit. "Not set on Generic Direct Drive 11.55MW (add it)" is the form saying the turbine record could own this field but does not — which is how an unmanaged input stops being a silent one.

Illustrative

Results lead with the width of the estimate

The CAPEX results page for the same scenario. Optimistic, expected, pessimistic and the range across them come before any breakdown, because the size of the estimate and how wide it is are what a reader is owed first. Below them, one band per component with the expected case ticked on it.

Project Demonstration project Scenario Default Scenario Project team
CAPEX OPEX AEP M&A Pre-FID WOMBAT

CAPEX Results

View a single scenario or compare up to 3 scenarios side-by-side.

Select scenarios

1 / 3
Default Scenario Base case
Wombat comparison Main component exchange in situ, not tow-to-shore
Scenario 3 15 MW Danish Hybrid 236 in place of the 11.55 MW machine

Default Scenario CAPEX Breakdown Analysis

Optimistic

£962m

Expected

£1,196m

Pessimistic

£1,435m

Range

£472m

Cost range by component

Optimistic to Pessimistic Expected

CAPEX by component, range across cases Floating substation £290m – £433m WTG supply £226m – £336m Floater hull £156m – £232m Onshore substation £139m – £208m Export cable system £60m – £90m Floater installation £33m – £50m Infield cabling £26m – £39m Mooring system £16m – £24m Corrosion protection £13m – £19m Equipment £2m – £3m Construction site £0.19m – £0.28m £0m£100m£200m£300m£400m
Component Optimistic Expected Pessimistic Share
Floating substation £290m £361m £433m 30.2%
WTG supply £226m £280m £336m 23.4%
Floater hull £156m £194m £232m 16.2%
Onshore substation £139m £173m £208m 14.5%
Export cable system £60m £75m £90m 6.3%
Floater installation £33m £41m £50m 3.5%
Infield cabling £26m £33m £39m 2.7%
Mooring system £16m £20m £24m 1.7%
Corrosion protection £13m £16m £19m 1.3%
Equipment £2m £3m £3m 0.2%
Construction site £0.19m £0.23m £0.28m 0.0%

Optimistic and pessimistic are the model's own other two cases, not a percentage applied to the expected one. A component whose cost is well understood has a narrow band and one that is not has a wide one — which is the reason the page leads with the range rather than a single number.

Illustrative

Twelve components, and what each one is worth

Below the range, the same estimate again as a card per component, with the total and its split in the middle. All three cases are on every card, because how uncertain a component is belongs beside what it costs.

Project Demonstration project Scenario Default Scenario Project team

Floating substation

Optimistic £290m
Expected £361m
Pessimistic £433m

WTG supply

Optimistic £226m
Expected £280m
Pessimistic £336m

Floater hull

Optimistic £156m
Expected £194m
Pessimistic £232m

Onshore substation

Optimistic £139m
Expected £173m
Pessimistic £208m

Export cable system

Optimistic £60m
Expected £75m
Pessimistic £90m

Floater installation

Optimistic £33m
Expected £41m
Pessimistic £50m

Total CAPEX

Optimistic £962m
Expected £1,196m
Pessimistic £1,435m
Capital cost split, expected case £1,196m Total, expected case

Cost breakdown

Parameters
Component Expected value Percentage
Floating substation £361m 30.2%
WTG supply £280m 23.4%
Floater hull £194m 16.2%
Onshore substation £173m 14.5%
Export cable system £75m 6.3%
Floater installation £41m 3.5%
Total £1,196m 100%

Infield cabling

Optimistic £26m
Expected £33m
Pessimistic £39m

Mooring system

Optimistic £16m
Expected £20m
Pessimistic £24m

Corrosion protection

Optimistic £13m
Expected £16m
Pessimistic £19m

Equipment

Optimistic £2m
Expected £3m
Pessimistic £3m

Construction site

Optimistic £0.19m
Expected £0.23m
Pessimistic £0.28m

Project currency set to GBP. Some data sources are USD and were converted at runtime at 0.7470 on 2026-09-20 — with the rate stamped on the result, so a figure quoted with differing exchange rates can be explained.

See it on your own project

Book a demo and we will walk through the module with your numbers, not ours.

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