The owners of the former Aberthaw power station have been granted a High Court injunction against trespassers.
It follows a spate of online videos by 'urban explorers' who managed to enter the coal-fired plant, which was decommissioned in March 2020.
CCR Energy, which brought the site for £8 million in 2022, says the injunction covers land within the construction design and management boundary and runs until March 2027.
Demolition work is currently taking place at the former power station, which has been earmarked for a green energy hub.
But the energy firm stressed it does not affect the nearby section of the Wales Coast Path, which remains open to the public.
A CCR Energy spokesperson said: "This supports our continued commitment to ensuring the highest standards of safety and security on the site while demolition and remediation works continue."
"The injunction will help prevent unauthorised access and trespassers, safeguarding both the public and on-site workforce. Warning notices will be displayed around the boundary to make the restrictions clear."
"The injunction applies exclusively to CCR Energy owned land within the CDM boundary and does not affect the coastal path - which remains open and fully accessible to the public."
CCR Energy is a subisdary of the Cardiff Capital Region, a group of ten local councils in South East Wales, including the Vale of Glamorgan.
They plan to transform the former Aberthaw power plant, which dates back to the early 1960s, into a "cutting-edge" low carbon destination.
A spokesperson added: "Beyond energy, the vision extends to delivering economic regeneration for the region - supporting new, high-value jobs, attracting investment, and fostering a hub for sustainable technologies."
"We remain committed to transparent engagement with local communities and stakeholders throughout the entire redevelopment journey and will continue to provide timely updates as work at Aberthaw progresses."
Earlier this year, it emerged CCR had settled a legal dispute for £5.25 million after the High Court ruled a contract to demolish the power station had been awarded unfairly - with the findings of an independent review due to be published by the end of the year.
Plans are under consideration to build over 200 houses in a sleepy Welsh village
Sanitary disposal bins introduced in men's public toilets following "Bins for Boys" campaign
Officers called to Dinas Powys Woods after young person enters the river
Three Reform candidates quit in Pen-y-Bont Bro Morgannwg constituency
Six events taking place in the Vale of Glamorgan this weekend
Vale Council signs off placemaking plan for Barry
Plans filed to use Blackweir Fields for a series of live events this summer
Plans filled for controversial housing development in Cowbridge
Cardiff Council pledges to work with new Welsh Government to tackle trouble-plagued hospital
Two local candidates stand down after revelations
RNLI issues Sully Island safety advice after first call out of the year to the Island
Morio Lounge on course to open at Nell's Point in May
Vale Council appoints specialist contractors to carry out road improvements
Three men jailed for their roles running a drugs line which supplied cocaine in Barry
Police appeal for witnesses after fatal Penarth Road collision
New Beach and country park facilities opened following major investement
RNLI centre at Barry Island welcomes lifeguards back to Whitmore Bay
Severn tidal lagoons progress
