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Capability · 08 / 09 · Decarbonisation

Maritime Decarbonisation

Pathways from fuel-burn baseline to net zero.

Lead time · 4–12 weeksFixed-fee, fixed-scopePrincipal-ledAuthor · Sérgio Ribeiro e Silva, PhDLast reviewed ·
✦ TL;DR

Maritime decarbonisation is the engineering work of moving a vessel or fleet from a measured fuel-burn baseline to a defensible net-zero pathway — battery, hybrid, LNG, methanol, ammonia, biofuel, or efficiency retrofit — under FuelEU Maritime, EU ETS Maritime, IMO 2023 GHG Strategy (MEPC.377(80)), and the Poseidon Principles. KDS Offshore, a 2016 spin-off of Instituto Superior Técnico (Lisbon), grounds every recommendation in CFD-quantified hydrodynamics, peer-reviewed voyage optimisation (IMDC 2024, ICCAS 2024), and well-to-wake lifecycle modelling.

Overview

What this service is

Maritime decarbonisation is no longer a strategic abstraction. FuelEU Maritime (Regulation (EU) 2023/1805), the EU ETS extension to shipping, the IMO 2023 GHG Strategy (MEPC.377(80)) — net-zero close to 2050, with a 20–30% absolute cut by 2030 and 70–80% by 2040 on a well-to-wake basis — and the Poseidon Principles all impose concrete, dated obligations on shipowners, operators, port authorities, and lenders. The question for the operator is no longer whether to decarbonise. It is which pathway closes on engineering, on schedule, and on CAPEX, and how that pathway is defended in front of the recognised organisation, the flag administration, and the financing bank.

KDS Offshore works the technical side end-to-end: operational emissions baselines well-to-wake against IMO DCS / CII methodology; alternative-fuel feasibility across battery, hybrid, LNG, methanol, ammonia, and second-generation biofuel; electrification and hybrid powertrain sizing; energy-efficiency retrofits (hull, propeller, appendages, waste-heat); shore-side power (OPS / cold-ironing) design; and operational optimisation — trim, speed, weather routing — through our published Ship Operation Optimisation System (SOOS). Every recommendation is grounded in CFD-quantified hydrodynamics, peer-reviewed methodology, and lifecycle GHG modelling. No generic ESG narrative.

Reference work includes the SEAPOWER 1500 — a 15 m fully electric pilot boat with a 664 kWh lithium-ion bank, sized by CFD pre-construction in 2025 — the OPS shore-power study for the Madeira port authority APRAM, delivered in partnership with Future Proman as the Green Ports Madeira programme (2023), and the "Belize I" catamaran remotorisation and capacity uplift for Nautiber (2023), delivered on schedule. Each engagement starts from a measured operational baseline and ends with a documented pathway the operator can defend to regulators and lenders.

The methodological backbone is published, not proprietary opacity. In 2024 the principal Sérgio Ribeiro e Silva and Miguel Bento Moreira (IST/CENTEC) presented the SOOS optimisation programme at the 15th International Marine Design Conference (IMDC 2024, Amsterdam, paper 832) and again at ICCAS 2024 (RINA, Genoa). On a 712 TEU geared containership in synthetic Atlantic conditions — a 23-knot westerly wind, a 2.14-knot westgoing current, a 1.25 m / 10 s regular west swell, and a 215 km leg — SOOS converged in under 100 epochs of Vectorized Simulated Annealing and reduced voyage fuel by 8–9% versus the great-circle direct route, holding the saving even with an obstacle (island, marine corridor) inserted in the search space. Combined with the principal's 25+ years of hydrodynamic research at IST and 364+ Google Scholar citations, the technical track record is auditable, not promotional.

The KDS frame: physics first, optimisation second, narrative last. CAPEX, OPEX, GHG, technology readiness, and refuelling availability are scored side by side for the candidate pathways — the operator gets a comparison matrix and a written recommendation, not a vendor pitch. When a pathway does not close on the numbers, we say so in the feasibility, not after the steel is being cut.

See our methods →

Outcomes

Numbers we expect to defend

100%
electric propulsion delivered
SEAPOWER 1500 — 15 m pilot boat, 664 kWh lithium-ion, sized by CFD pre-construction (SeaPower, 2025)
8–9%
voyage fuel saved on Atlantic case
712 TEU geared containership, SOOS programme — peer-reviewed IMDC 2024 + ICCAS 2024
<100 epochs
optimisation convergence
Vectorized Simulated Annealing inside the SOOS stack — operator-grade real-time response
OPS
shore-power design for Madeira port authority
Green Ports Madeira / APRAM via Future Proman (2023)
6 pathways
compared per fleet study
battery, hybrid, LNG, methanol, ammonia, biofuel — scored on CAPEX, OPEX, GHG, TRL, refuelling availability
30%
IMO 2030 GHG reduction target (well-to-wake)
MEPC.377(80) — the floor for the operational pathway we engineer toward
Deliverables

What you get

01
Operational emissions baseline (well-to-wake) — DCS / CII / MRV compliant
02
Decarbonisation pathway comparison matrix (battery / hybrid / LNG / methanol / ammonia / biofuel / efficiency retrofit)
03
Alternative-fuel feasibility study with refuelling-availability map
04
Electrification & hybrid powertrain sizing (battery, genset, fuel cell)
05
Energy-efficiency retrofit specification (hull, propeller, appendages, waste-heat)
06
OPS / shore-side power design for port authorities and operators
07
Optimal renewable energy mix calculation for ports
08
CFD-quantified resistance & propulsion curves over the operational envelope
09
Voyage optimisation deployment (SOOS — trim, speed, weather routing)
10
FuelEU Maritime / IMO 2050 / EU ETS / CII compliance assessment
11
Lifecycle GHG model with CAPEX / OPEX envelope and break-even analysis
12
Technical annexes for Poseidon-Principles / Sea Cargo Charter disclosure
Fit

When this is the right call

✓ When to use
  • A FuelEU Maritime, EU ETS Maritime, or CII compliance gap that needs a technical answer with auditable methodology — not a glossy ESG report.
  • A fleet renewal or remotorisation decision where battery, hybrid, methanol, ammonia, and biofuel are all candidates and the operator needs a defensible comparison matrix.
  • A port authority or charterer demand for shore-side power (OPS / cold-ironing), alternative-fuel readiness, or measured well-to-wake reporting.
  • A lender, recognised organisation, or off-taker requesting a defensible technical annex for green-finance, Poseidon Principles, or Sea Cargo Charter disclosure.
  • An existing-ship EEXI verification needing a CFD-validated calm-water resistance curve and Holtrop-Mennen sanity check.
  • A CII rating downgrade (D or E) requiring a remedial plan with operational + retrofit measures scored against the regulatory clock.
  • A vessel due for routine drydock where the operator wants to bundle an efficiency retrofit (hull cleaning regime, propeller optimisation, appendage redesign) onto the existing scope.
✗ When not to use
  • A pure ESG-marketing brief without an operational baseline (we are engineers, not communications consultants).
  • A duty cycle where the operator has not yet measured or estimated fuel consumption — start with a one-week onboard logging effort first.
  • A request to "pick a fuel" without a vessel, route, or charter context — the answer depends on the operational profile we have not seen.
Methodology

How we run a project

  1. 01 / 06

    Baseline & boundary

    Define the operational profile — voyages, port time, fuel mix, environmental conditions, charter constraints. Build the well-to-wake emissions baseline against IMO DCS / CII / MRV methodology. Onboard logging where the data does not exist yet.

  2. 02 / 06

    Pathway options

    Score battery, hybrid, LNG, methanol, ammonia, biofuel, and efficiency-retrofit options against CAPEX, OPEX, GHG reduction, technology readiness, refuelling availability, and the regulatory clock (CII targets, FuelEU limits, EU ETS phase-in). Output is a defensible comparison matrix the operator can hand to the board.

  3. 03 / 06

    Engineering sizing

    For the selected pathway, full engineering: powertrain, battery, fuel system, integration, structural fit, weight and stability impact, GA updates, electrical single-line, classification rule check. CFD where it changes the answer (hull, propulsion, appendages, OPS connection arrangement).

  4. 04 / 06

    Operational optimisation

    Deploy SOOS where the route is non-trivial: Vectorized Simulated Annealing weather routing on CFD-derived calm-water power, semi-empirical wind loads, Salvesen-1978 added resistance in waves, trim through centre-of-gravity. Tested on the 712 TEU SOOS reference case at 8–9% fuel saving.

  5. 05 / 06

    Compliance & financing

    Prepare the FuelEU Maritime, EU ETS, IMO 2050, CII, and Poseidon-Principles technical submissions. Liaise with the RO (DNV / BV / RINA / LR) and the flag administration. Hand the operator the technical annex the lender needs for green finance.

  6. 06 / 06

    In-service monitoring

    ISO 19030 performance-monitoring framework with the CFD model as the physics anchor. Continuous benchmarking against baseline; flagged drift triggers a hull-cleaning recommendation or a re-baselining run. Optional — typically combined with our Digital Twin service.

Tools & methods

Software stack we use

  • STAR-CCM+ / OpenFOAM / Simerics MP — CFD
  • WAMIT — diffraction / radiation, OPS structural loading
  • Rhino + Grasshopper — parametric powertrain & hull design
  • Holtrop-Mennen — empirical resistance sanity check
  • Salvesen-1978 — added resistance in waves
  • SOOS · Vectorized Simulated Annealing (KDS, peer-reviewed)
  • Ship@Sea — KDS proprietary time-domain seakeeping
  • FuelEU Maritime / IMO DCS / CII methodology
  • EU ETS maritime calculator
  • Poseidon Principles & Sea Cargo Charter disclosure templates
  • MATLAB / Simulink — powertrain sizing, control logic
  • Python · NumPy · SciPy · pandas — lifecycle GHG modelling
  • ISO 19030 — in-service performance monitoring
Regulatory context

Frameworks we help you satisfy

  • FuelEU Maritime (Regulation (EU) 2023/1805) ↗Annual GHG intensity limits on energy used on board EU-trading ships from 1 January 2025; tightens stepwise to −80% by 2050.
  • EU ETS Maritime (extension 2024)CO₂ allowances for ships ≥5,000 GT trading to EU ports; 40% phase-in 2024, 70% in 2025, 100% in 2026.
  • IMO 2023 GHG Strategy (MEPC.377(80))Net-zero close to 2050; 20–30% absolute reduction by 2030; 70–80% by 2040; well-to-wake basis.
  • IMO CII (Resolution MEPC.336(76))Annual carbon intensity rating A–E; remedial plan required for D (3 consecutive years) or E (single year).
  • IMO EEXI (Resolution MEPC.328(76))Energy Efficiency Existing Ship Index — one-off verification at first survey after 1 January 2023.
  • EU MRV (Regulation (EU) 2015/757)Monitoring, reporting, verification of CO₂ emissions on EU-trading ships; feeds FuelEU + EU ETS.
  • IMO DCS (MEPC.278(70))Data Collection System on fuel oil consumption — feeds CII calculation.
  • Poseidon PrinciplesBank-led climate-alignment disclosure framework; technical annex required for financing.
  • Sea Cargo CharterCharterer-led equivalent of Poseidon Principles — emissions disclosure for cargo owners.
  • ISO 19030 — ship performance & fuel consumption monitoringIn-service performance monitoring methodology; underpins efficiency-retrofit verification.
Vessel types

Where this discipline applies

  • Pilot boats, harbour craft, port-authority fleets — SEAPOWER 1500, APRAM
  • Ferries and short-sea passenger (RoPax included)
  • Container ships and feeders — published SOOS validation case
  • Tankers and bulkers (EEXI + CII focus)
  • Tugs and offshore service vessels (OSVs)
  • Cruise vessels (operational efficiency, OPS retrofit, MEG4 mooring upgrade)
  • Working boats, aquaculture, and scientific-research vessels
  • Wave-energy converters and floating-wind support vessels
Selected work

Where this discipline was used

·01SEAPOWER 1500 — fully electric 15 m pilot boat (CFD-sized pre-construction)SeaPower2025↗·02Green Ports Madeira — OPS / shore-power design for APRAM port-authority fleetAPRAM via Future Proman2023↗·03"Belize I" — catamaran remotorisation & passenger-capacity upliftNautiber2023↗·04SOOS — real-time voyage optimisation (712 TEU containership, 8–9% fuel saved)KDS R&D · IST/CENTEC2024↗
Common questions

FAQ

Which fuel pathway is right for my fleet?

There is no universal answer. We start from your operational profile — voyage length, port time, refuelling availability, charter constraints, CAPEX envelope, and the regulatory clock against your CII / FuelEU / EU ETS exposure — and score battery, hybrid, LNG, methanol, ammonia, and biofuel against your specifics. The output is a comparison matrix and a written recommendation, not a vendor pitch.

Are you certified for FuelEU Maritime reporting?

We follow the published FuelEU Maritime methodology (Regulation (EU) 2023/1805) and the IMO DCS reporting framework, and we deliver assessments in the format flag-state administrations and recognised organisations expect. Final FuelEU certification is issued by the RO (DNV, BV, RINA, LR); we prepare the technical submission, the well-to-wake calculation, and the answers to RO queries.

Can you retrofit existing vessels, or only design new builds?

Both. For most operators retrofit is more economical than newbuild in the short term. We have remotorised pilot boats, converted catamarans (Belize I), and specified hybrid retrofits. Each engagement starts with a feasibility study covering structural fit, weight balance, range, regulatory approval, and the operational saving versus the CAPEX. We say no when the case does not close.

How do you handle a CII rating jump from D to C?

A CII downgrade demands a remedial plan, not a press release. We baseline the vessel against the trajectory, identify the lowest-CAPEX measures with verified saving (trim optimisation, hull cleaning regime, propeller optimisation, weather routing via SOOS), and stack them with retrofit options (waste-heat recovery, shaft generator, hybrid). Each measure is scored on engineering saving + compliance gap closed + payback. We document the plan in the format the RO accepts.

Can savings be measured before retrofit, or only after?

Both. Before retrofit: CFD-derived power curves over the operational envelope feed a digital twin that projects savings under historical operating conditions, with documented uncertainty bands. After retrofit: ISO 19030 in-service monitoring measures the realised saving against the same baseline, with the CFD model as the physics anchor. The operator gets a quantified before / after comparison the financier can audit.

Do you cover OPS / shore-side power design for port authorities?

Yes. Reference work: the Green Ports Madeira programme with the APRAM port-authority fleet, in partnership with Future Proman (2023). Scope typically includes connection-arrangement design, vessel-side electrical interface, port-side substation sizing, regulatory interface with the flag administration, and the GHG accounting that shows the saving against the EU ETS / FuelEU baseline.

Research

Reference publications

  1. [1]Ribeiro e Silva, S., Bento Moreira, M. (2024). An optimisation-based approach to reduce fuel consumption and emissions from shipping navigation. 15th International Marine Design Conference (IMDC 2024), Amsterdam. ↗
  2. [2]Ribeiro e Silva, S., Bento Moreira, M. (2024). An integrated real-time Ship Operation Optimisation System (SOOS) to reduce fuel consumption and emissions from shipping navigation and port calls. ICCAS 2024, RINA, Genoa.
  3. [3]Ribeiro e Silva, S., Varela, J. M. (2022). Ship Gyroscopic Roll Stabilisation. OMAE 2022, ASME, Hamburg. Paper OMAE2022-7953 — BEM with speed corrections + ST methodology informing energy-efficiency retrofit decisions.
  4. [4]Costa, P., Ribeiro e Silva, S., et al. (2018). Atmospheric emissions from pellet energy supply chain: a Portuguese case study. Air Quality, Atmosphere & Health, 11(2), 197–207. Track record on well-to-wake emissions accounting.
  5. [5]Ribeiro e Silva, S. et al. (2021). Model testing of floating wave energy converter with internal U-shaped oscillating water column. Energy Conversion and Management, Vol. 240 — coupled hydrodynamic / energy methodology underpinning renewable-energy decarbonisation work.
Other capabilities

Eight other disciplines, one office

✦ Brief this service · Decarbonisation

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