Global Overview of Commercial Electric Propulsion and Zero Emission
If commercial shipping was a nation, it would have the 6th highest greenhouse gas emissions in the world and this has to be addressed. That’s why around the world, commercial vessels are going electric.

The International Maritime Organization created a standard in 2011 called the EEDI, or Energy Efficiency Design Index, which became a measured standard in 2011. Then, in 2013, 2018 and every five years going forward, newly built ships are required to have their EEDI increase 10% and thereby reduce greenhouse gas emissions. A second edition of the comprehensive report of emission reduction strategies for commercial vessels was completed in March 2021 by the Global Maritime Forum
The International Maritime Organization created a standard in 2011 called the EEDI, or Energy Efficiency Design Index, which became a measured standard in 2011. Then, in 2013, 2018 and every five years going forward, newly built ships are required to have their EEDI increase 10% and thereby reduce greenhouse gas emissions. A second edition of the comprehensive report of emission reduction strategies for commercial vessels was completed in March 2021 by the Global Maritime Forum
US Laws and Incentives for Commercial Electric Propulsion and Emission Reduction
The US regulatory framework for engines is based on classifying diesel engines in five tiers based on emissions. Of note, the standard differs based on the size of the engine.
Engine Tier | NOx (g/kWh) | PM10 (g/kWh) |
---|---|---|
Tier I | 9.8 | No standard |
Tier II | 8.7 – 9.8 | .27 – .50 |
Tier III | 6.2 – 11.0 | .14 – .27 |
Tier IV | 1.8* | .04 – .25 |
* Tier 4 engines are NOx, Tier1-3 are NOx + HC

- For more EPA Emission Standards forMarine Compression-Ignition (CI) Engines
- Funding is available through the Diesel Emission Reduction Act of 2005 and 2010. More information about DERA is available from the EPA
Most often, grants for engine repowers to cleaner diesel engines or zero-emission technology such as electric propulsion is administered at the state level with DERA funds from the federal government. Over $70M is provided in grants to public and private vessel owners annually in the United States for reducing diesel emissions. The amount available for the marine sector varies widely by state with California having $30M to allocate and Florida having $1M to allocate. The variation is based on what the state environmental agency applying for the grant requests, which in turn is based on regulations and promotion of these grant opportunities.
If you are a commercial vessel operator who wants to convert your boat to electric propulsion, outside of California there is a good chance there are not funds immediately available. Green Yachts suggests contacting us and together working with your state’s environmental agency and your state’s transportation agency to secure DERA funds and other grants to pay for the majority of your electric conversion. This is important because DERA funds alone can fund 60% of the cost for a commercial vessel converting to electric propulsion and 25% of the shore power charging facility costs.