The DOE instead opted for programmes being developed by Fishermen's Energy in New Jersey, Dominion Virginia Power in Virginia, and Principle Power in Oregon. The aim of the funding is to develop projects that build on and add to those designed for the European market.
UMaine was instead selected as an alternative project. It will receive $3 million in funding to help the research and development and complete the design stage.
Aqua Ventus will be in line to get the full funding should one of the projects chosen to receive the $47 million fail to meet requirements such as gaining a power purchase agreement.
Unlike the three chosen projects, UMaine has installed a prototype turbine on a floating platform and could have been considered to be a favourite for full funding.
Jake Ward, vice president for innovation and economic development told Windpower Monthly the project is positive about the future.
"It is disappointing but we are looking forward – additional funding to complete 100% design shows support and enthusiasm towards the design and innovations," he said.
Ward, however, admitted that the team was still unclear why the Aqua Ventus project missed out on the DOE grant, despite having a working prototype installed off the Maine coast.
"We have not been given that information. We believe we met all the criteria for the requirements but DoE made their decisions for many reasons.
"The future is still bright, completing 100% design and engineering is a critical path in any case. The technology has a very wide range of applications where water depth is too deep for bottom-mounted technology.
"The DoE program is still important overall to open the potential for offshore wind in the US," he added.
Ward did reveal the project was discussing a power purchase agreement with the state's Public Utilities Commission (PUC) over the coming months.
The floating turbine received state approvals from the PUC in January for a demonstration site consisting of two 6MW turbines on the semi-submersible foundations.