The group's tax returns for 2010 showed the group had raised $1.8 million in 2010 compared to $1.4 million in 2009.
However, Cape Wind dismissed the uplift in donations and pointed out the 2010 figure was still lower on average to what was received prior to 2009. In 2004 it was handed $4.7 million.
Cape Wind communications director Mark Rodgers said: "Project opponents have nothing to celebrate here, the fact of the matter is they ended the year $1.35 Million in the hole, 2010 was a very bad year for them financially.
"We know from past reports that one of their largest donors is Bill Koch, a coal and oil magnate who this opposition group once disclosed was directly paying the salary of their CEO."
Although all of the necessary permits are in place for the 469MW project, the developers only have a power purchase agreement in place for half of the project.
In October, Cape Wind has asked the Massachusetts Department of Public Utilities to make the merger of two utilities NStar and Northeast Utilities conditional on signing a power purchase agreement with the wind farm.
Earlier this year, there was speculation that the company may tap into the bond market for financing. The move followed a decision by the Department of Energy to shelve the company's application for a loan guarantee for the $2 billion project.