MARitime · Energy · Infrastructure · Ventures · Advisory
Advisory for shipping companies, port operators, energy developers, and investors navigating alternative fuels, electrification, shore power, commercial developments and contracts in the maritime energy transition.
The problem
Why reports don't land
The maritime energy transition has produced a large market for strategy frameworks and regulatory roadmaps. Most are never implemented as written. The gap between a polished deliverable and operational reality is where clients lose time and money.
What most teams are missing
The transition requires simultaneous fluency in regulation, commercial modelling, and contract execution. Most organisations have depth in one, rarely in all three — and the gap between them is where projects stall and deals go wrong.
Where Mareiva operates
Between regulatory obligation and bankable project. Between fuel option and signed supply contract. Between decarbonisation target and a decision that can actually be implemented, executed, and verified.
Who we work with
Port authorities and terminal operators under OPS mandates. Shipping companies facing compliance decisions — EU-ETS, FuelEU Maritime, RED — building multi-fuel portfolios, navigating energy markets, or evaluating shore-side OPS and onboard electrification. Fuel producers, project developers, and investors building the commercial infrastructure for the energy transition.
Our Mission
Mareiva exists to close the gap between maritime energy ambition and commercial reality. We work with port operators, shipping companies, fuel producers, investors, and energy developers to turn regulatory obligations and fuel transition decisions into contracts that hold, models that reflect reality, and projects that get built.
The maritime energy transition has generated a large market for frameworks and reports. Most are never implemented as written. The gap between a polished deliverable and operational reality is where clients lose money and time.
Every engagement is designed around a decision that needs to be made or a contract that needs to be closed. The measure of success is whether the client can act on it — and whether the results are what was projected.
Services
OPS mandates are live. The gap between regulatory obligation and a bankable project is large — grid connections, CAPEX structuring, offtake agreements, vessel compatibility. Mareiva closes that gap with operator-grade financial modelling and commercial advisory from feasibility to FID.
The fuel choice is not just technical — it is commercial, regulatory, and contractual simultaneously. Mareiva delivers fuel portfolio assessments with full-chain TCO modelling, compliance mapping against FuelEU and EU-ETS, and end-to-end fuel trial management including procurement, testing, and verification.
For shipping companies and fuel producers who need the right commercial contract — one that anticipates risk, creates value for both sides, and holds up through implementation. Pricing strategy, supply contract negotiation, and portfolio structuring for producers entering the maritime market.
How Mareiva works
"Mareiva delivers outcomes that can be implemented, executed, and verified — not advice that requires another layer of translation before it reaches a decision."
— Working principle, MareivaEvery engagement starts from the specific decision the client needs to make — and what would need to be true for them to make it with confidence.
Financial models built to withstand counterparty scrutiny. Commercial frameworks that reflect how the sector actually works, not how it is described in regulatory guidance.
Engagements structured around what the client needs — from a focused modelling sprint to an ongoing advisory retainer through a project development cycle.
About
Jacopo Zanetti
Founder, Mareiva · Copenhagen
15+ years of international experience across energy, maritime and infrastructure
Mareiva was founded because the maritime energy transition is generating decisions that are too commercially complex for pure technical advisers and too operationally specific for generalist strategy firms.
The background is beyond consulting. It is in-field commercial experience: structuring commercial contracts, building OPS models and procurement processes, untangling energy and freight markets complexity, managing biofuel trials from procurement to post-voyage verification. That experience is what Mareiva brings to every mandate.
Mareiva works best when brought in early — before the model is built, before the term sheet is signed, before the contract is negotiated. The earlier the conversation, the more useful it is.