Zero Emission Maritime Buyers Alliance



The Zero Emission Maritime Buyers Alliance (ZEMBA) is a first-of-its-kind buyers group within the maritime sector with the mission to accelerate commercial deployment of zero-emission (ZE) shipping, enable economies of scale, and help cargo owners maximize emissions reduction beyond what any one freight buyer could accomplish alone. Through demand aggregation and a competitive forward procurement process, ZEMBA members will gain early access to ZE shipping services not currently available and build confidence among the rest of the maritime value chain to invest in ZE solutions.

ZEMBA is an initiative of Cargo Owners for Zero Emission Vessels (coZEV) and facilitated by the Aspen Institute Energy & Environment Program.

Prospective Members - Join Now

ZEMBA membership is open to any company that purchases ocean-going, container freight services. Together, members will:

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ZEMBA membership is open to any company that purchases ocean-going, container freight services. Together, members will:

  • Gain access to low risk, cost competitive environmental attributes associated ZE shipping services
  • Lower Scope 3 emissions
  • Catalyze ZE investments across the maritime sector
  • Effectively demonstrate climate leadership

When considering ZEMBA membership, please remember:

  • There is no membership fee
  • Contracting is bilateral with no impact to your current logistics or procurement practices
  • By acting ahead of regulation, your company can show demonstrable climate leadership and avoid the costs of delayed action
  • There is no obligation to participate in future RfPs

To join ZEMBA as a member, please email

Download Zemba One Pager

Prospective Bidders

In September 2023, ZEMBA launched a Request for Proposals (RfP) for 600,000 twenty-foot containers (TEUs) over a three-year period on ocean vessels powered by ZE fuels.

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This RfP will help ZEMBA members reduce ~1 million metric tonnes of carbon emissions, equivalent to taking 215,000 cars off the road. The RfP is the first major buyer-led initiative to accelerate the transition to zero-emission maritime fuels.

For the RfP, ZEMBA has developed a multifaceted ZE fuels criteria and in depth lifecycle analysis (LCA) guidelines to guide bidders in their submission of bids.

For this first RfP, ZEMBA will consider bids that meet the following criteria:

  • Sufficient capacity to cover 600,000+ TEUs across a distance of 6,000 nautical miles/~11,000 km over three years.
  • Fuels that provide GHG emission reductions of at least 90% compared to traditional fossil fuels on a lifecycle basis.
  • Transparent fuel lifecycle emissions to validate emission reduction claims.

ZEMBA’s ZE fuels definition and LCA guidelines used in this first-round RfP can be found below.

All interested carriers who can meet ZEMBA’s qualifications are welcome to bid. To access the RfP document, contact us.

For potential bidders interested in gaining more information specifically about the RfP, please email

Zemba Ze Fuels Definition

Zemba LCA Guidelines

Zemba Members

  • LAUNCH: Zero Emission Maritime Buyers Alliance

    MAR 2023

    Co-founders announced: Aspen Institute, Amazon, Patagonia, Tchibo

  • RfP “Coming Soon” Announcement

    Jul 2023

    Notice to carriers about volume, emission reduction goal and timeline to allow additional carrier preparation time

  • RfP Release

    SEP 2023
    • ZEMBA members seeking to buy environmental attributes of ZE shipping
    • Volume goal: 600K+ TEU on SH–LA benchmark distance, or 
3.5Bn TEU-miles total, over three years
    • Individual carrier or consortia welcome to bid
    • 20+ members ready to make three-year commitments
  • RfP Submissions Due

    Nov 13, 2023
  • Bid Consideration

    Nov 2023 – Q1/Q2 2024

    Evaluate and validate bids, obtain final volume commitments for each price tier

  • Announce RfP Winner, Final TEU Volume

    Q1/Q2 2024
  • Grow and Repeat


    Launch second round ZEMBA Tender Q4 2024