Below are frequently asked questions about ZEMBA’s work. For specific FAQs about ZEMBA’s inaugural tender, please visit our RFP 1 page.
Note that shipping companies are referred to as “carriers” and the term “freight buyers” is used to describe companies who utilize ocean freight services – both freight forwarders and cargo owners.
If you have any additional questions not covered here, please reach out to the ZEMBA team.
What is ZEMBA and what is its mission?
The Zero Emission Maritime Buyers Alliance (ZEMBA) is a first-of-its-kind buyers group within the maritime sector, the aim of which is to accelerate commercial deployment of clean energy-powered shipping, enable economies of scale, and help cargo owners maximize their positive impact beyond what any one freight buyer could accomplish alone.
By working together, ZEMBA members are offering committed demand to build confidence among investors, carriers, ship owners, and producers of clean energy fuels and renewable energy to invest in these solutions.
ZEMBA is incorporated as a non-profit entity in Washington, D.C. The Aspen Institute’s Energy and Environment Program serves as ZEMBA’s secretariat.
Who is eligible for ZEMBA membership?
ZEMBA membership is open to cargo owners, freight forwarders, or aggregators with eligible Scope 3 obligations wishing to purchase environmental attribute certificates from sustainable container shipping. This could include members operating in segments beyond container, pending the nature of their Scope 3 obligations.
For examples of our members, please see the ZEMBA homepage. If you have questions about ZEMBA membership, please reach out via the Join Us page.
What are the benefits of joining ZEMBA for freight buyers?
Joining ZEMBA provides several benefits for companies committed to reducing their supply chain emissions. These include:
- Greater emissions reduction impact: By coming together, ZEMBA members can have a greater impact than they could on their own, both in terms of supporting the establishment of a new clean energy maritime fuels marketplace and reducing maritime emissions.
- Economies of scale: By collaborating on the forward procurement of clean energy-powered shipping through ZEMBA, freight buyers can leverage collective action and support the short and long-term economic viability of the transition to scalable fuel and technology solutions.
- Certainty: Supply of clean energy fuels may be constrained in the early years as the market matures, potentially leading to challenges in securing emissions reductions and temporary cost increases before clean energy fuel prices begin benefiting from scale and price level out. Through ZEMBA, member companies can lock in supply and pricing, allowing them to better plan their long-term costs, build the business case internally, and ensure they are supporting the right solutions now to enable them to meet their net-zero commitments in the future.
- Innovation: ZEMBA’s collective demand signal aims to drive innovation in the maritime and alternative fuel industries as carriers and other value chain actors seek to compete for customer demand by offering the greatest lifecycle emissions reduction from adoption of scalable solutions at the lowest cost.
- Market Intel: ZEMBA’s technical and legal experts provide members with real-world intel on the development of a clean energy maritime market. Members are eligible to attend ZEMBA-specific webinars and receive newsletters with the most up-to-date information on the state of the sector’s clean energy transition, including emerging technologies and policy changes.
- Leadership opportunities: ZEMBA regularly communicates through multiple channels about the important leadership role our member companies play. While we can be highly effective ambassadors, audiences also want to hear from our companies directly. For that reason, we also coordinate opportunities for members to demonstrate their leadership and network with like-minded companies. This includes invitations to speak at events, webinars, and podcasts, engage in traditional media outreach, and support social engagement, etc. Engagement in these activities is always optional for members.
- Bespoke Modeling and Tools: In consultation with top experts, ZEMBA develops various specific tools to support members’ journey overall and their participation in ZEMBA’s tender processes.
Why is ZEMBA needed now?
The shipping sector is responsible for nearly 3% of global greenhouse gas (GHG) emissions. Delaying action to address these emissions and/or only investing in short-term “bridge” solutions that will struggle to achieve scale and economic viability will almost certainly result in a clean energy transition that is more disruptive and expensive for the entire value chain. A better way to achieve our goals is to act together today to ensure a smooth and affordable transition.
Fuel production and maritime assets are long-term investments, e.g., vessels built today may still be on the water beyond 2050. Derisking those value chain investments through offtake commitments from freight customers is a key objective of ZEMBA.
Ambitious action is needed to catalyze the clean energy transition. Solely focusing on short-term efficiency measures or expanding use of high lifecycle emission “bridge” fuels will impede the development and deployment of the scalable, sustainable fuels needed to fully transition the sector.
By acting collaboratively now through ZEMBA, freight buyers can support a competitive market for long-term clean energy solutions early in the transition. This will enable us to increase our chances of experiencing a smooth and affordable transition in the long run.
By brokering advanced market commitments, ZEMBA aims to support the business case for investment in steadily increasing clean energy fuel supply. The longer the maritime shipping sector waits to transition, the more challenging and expensive it will be to meet emissions reduction targets.
Who won ZEMBA’s inaugural tender?
Hapag-Lloyd was the winner of ZEMBA’s inaugural tender. As a result, in 2025 and 2026, Hapag-Lloyd will deploy clean energy-powered shipping of over 1 billion million twenty-foot equivalent units (TEU)-miles using exclusively waste-based biomethane, resulting in at least 82,000 metric tonnes CO2e emissions avoided. In order to reduce fuel transport emissions and extra cost, this fuel will be delivered through the European gas grid on a mass balance basis compliant with the European Union’s Renewable Energy Directive II and is expected to reach a percentage reduction in CO2e emissions over low-sulfur fuel oil (LSFO) in the low to mid 90’s on a voyage basis (i.e., per unit of transport work).
What criteria were used in evaluating the first RFP bids?
ZEMBA’s Request for Proposals (RFP) sought bids for shipping services, from individual carriers or consortiums, that were able to achieve at least a 90% reduction in greenhouse gas emissions compared to traditional fossil fuels on a lifecycle basis. To be eligible for consideration, bidders needed to be able to meet ZEMBA’s aggregated volume total of 1.15 billion TEU-miles per year on ocean-going vessels powered by zero emission fuels, with deployment starting in 2025. The primary criteria that shaped ZEMBA’s evaluation of bids received were:
- Compliance with ZEMBA’s RFP 1 Sustainability Framework
- Ability to meet ZEMBA’s target volume
- Deployment timeline
- Transoceanic route
- Price
How do the outcomes of ZEMBA’s inaugural tender support the development of scalable, sustainable fuels of the future?
With the launch of its inaugural tender in 2023, ZEMBA set the highest global standard for procurement of greenhouse gas emissions reduction for deep-sea transport and will continue to increase ambition over time as ever more scalable and sustainable solutions meet commercial readiness. In doing so, ZEMBA is demonstrating to all actors in the value chain that best-in-class standards for fuel certification, service verification, pricing transparency, and high-integrity processes to ensure credibility of claims are indeed attainable now. ZEMBA’s collective procurement sends an important demand signal and allows freight buyers that are newer to clean energy-powered shipping to confidently invest in a robust and verified sustainable shipping, which helps further amplify this demand signal.
Equally importantly, ZEMBA has demonstrated that the process of aggregating freight buyer demand and going to market through an open competitive process works. This initial success from RFP 1 sets the stage for continuous refinement in subsequent tenders so that ZEMBA can continue to push the boundaries of what is technically and economically possible in the clean energy transition of the maritime sector over time.
An example of how ZEMBA continues to push the boundaries of the maritime sector’s clean energy transition is demonstrated by its e-fuel-focused tender. Visit the RFP 2 webpage for more information.
How does ZEMBA rely on Book and Claim approaches and why?
As clean energy-powered shipping services come to market initially, it is highly unlikely that these services will deploy exactly where and when each ZEMBA member company needs to move ocean freight. The ability to decouple physical freight movement from willingness to pay a premium for transparent, verified emissions reduction is essential to accelerate the transition in this sector.
The development of a rigorous, verifiable book and claim chain of custody system(s) will play a key role in accelerating the early phases of the clean energy transition in shipping and other hard-to-abate sectors. Such systems are under development by partner organizations now, as are efforts to ensure that credible Scope 3 emissions reductions through such systems will be supported under various carbon accounting and target-setting frameworks.
ZEMBA members and Hapag-Lloyd, among numerous other partners, are working with the Maersk Mc-Kinney Møller Center for Zero Carbon Shipping and RMI on the development of their maritime book and claim system known as Katalist. ZEMBA will be using this system to book and claim the emissions reductions from its first tender and hopefully subsequent tenders as well.
It is important to emphasize that this is NOT offsetting. Rather, these are in-sector investments in real deployment of clean energy fuels and technologies by supply chain actors within that sector to credibly reduce emissions and enable customers of that sector to help cover the added cost in return for due credit. In other words, ZEMBA members enable the winning carrier(s) to make a real verified fuel switch on ocean-going ships that leads to measured emissions reduction.
Why was the inaugural winning bid not an e-fuel? Will ZEMBA focus on e-fuels in the future?
ZEMBA did not receive any e-fuel bids for its first tender. The only bids ZEMBA received that were commercially mature enough to meet its 90% emissions reduction threshold, aggregated volume target, and 2025 deployment timeline were advanced biofuel solutions. Through the first tender, ZEMBA uncovered that the market for e-fuels was unfortunately still nascent and carriers were hesitant to uptake those fuels.
For the second tender, ZEMBA is specifically focused on aggregating demand for e-fuel-powered shipping services for deployment starting in 2027. A request for information conducted by ZEMBA and Lloyd’s Register Decarbonization Hub in summer 2024 revealed that e-fuels should be available starting in 2027, and that there will be sufficient vessels on the water capable of using those fuels. By setting an e-fuel requirement, we hope to connect those areas of progress and catalyze the first collective e-fuel deployment in this sector at scale.
Why clean energy fuels? Why not just use fossil fuels more efficiently?
Studies from Lloyd’s Register and UCL/UMAS have demonstrated that while many technical and operational efficiency measures are currently available and should be deployed to reduce emissions in the maritime sector, they alone are not enough. Operational and technical efficiency measures can, at most, provide a 50% carbon intensity reduction for fossil-powered shipping. Therefore, a full-scale transition to clean energy fuels and technologies, combined with maximum feasible use of efficiency measures, is necessary. Given the predicted long arc of this transition, the pace of change must accelerate quickly.
For ZEMBA’s second tender, ZEMBA is focused on catalyzing the commercial deployment of e-fuels, seen by many as the most sustainable, scalable solution to achieve the clean energy transition of the maritime sector. To learn more, visit the RFP 2 page.
Will these fuels cost more, and what impact will this have on freight buyers?
It is generally understood that clean energy fuels may cost more than fossil fuels in the early years, until there is sufficient policy support to close the cost gap and large-scale deployment of those fuels to achieve economies of scale. That goal can only be reached if leaders step up now to create the initial framework and demand for building this new market.
ZEMBA members are signaling that they want a competitive and economically viable marketplace for clean energy-powered shipping, that they are interested in working with other freight buyers and actors across the value chain to be able to build and participate in that marketplace, and that policy support will be essential to achieving scale and success in the long run. Freight buyers will continue to make independent procurement decisions as this energy transition in shipping unfolds, even as they engage with ZEMBA to accelerate the transition through collective action.