Cornwall Council approved plans for the multimillion pound collaboration between the Eden Project and geothermal experts EGS Energy in 2010 but the project stalled.
The design envisaged boring holes three miles into the underlying granite through which water would be pumped. The earth's heat would raise its temperature to 240C, producing steam which would power a turbine generating all the Eden Project's electricity needs.
EGS Energy is now asking Cornwall Council to give it more time and revise the timescale which was imposed by the previous conditional approval.
It is hoped this will allow time to find the development cash needed.
