The partners in a plan to develop a future vision for a former nuclear site have said it could "relaunch the economy" of Dumfries and Galloway.
The council, Scottish Enterprise and Nuclear Decommissioning Authority have signed up to the Chapelcross project.
For the past five years, efforts have focused on boosting employment - particularly for former plant workers.
Now their attention is turning to attracting businesses to the site, such as low-carbon energy providers.
Bill Hamilton of the site owners, the NDA, said it was a massive opportunity.
"In total we have got something like 95 hectares of land - that is an enormous site, that is a site of strategic importance for Scotland," he said.
"A major proportion of that land actually is available right now."
He said the site's connection to the National Grid made it particularly attractive.
"That is why it is of great interest to energy companies - both companies that want to generate energy and companies that want to use energy," he said.
"It is a great asset.
"It has got some challenges but this memorandum that we have signed means that we are all working together to really bring it to fruition."
Dumfries and Galloway Council chief executive Gavin Stevenson said there was an opportunity to use the site's energy generating history in more green ways.
He said the location near the Scotland-England border and infrastructure available were other selling points.
"We have got the motorway, we have got rail lines, we have got internet cables and we have got the main power grid connection - as an investment opportunity, it is fantastic," he said.
"The fact that we have partnership, we have no barriers to taking forward inward investment, is unique in Scotland, I think, for this site."