Residents living near the site of a proposed gas-fired power plant on the NSW Southern Highlands say they are "devastated" by the prospect.Sydney company Nakar Property and its subsidiary Cloud Carrier want to build three gas-fired power stations with a combined capacity of more than 700 megawatts (MW) on a site less than 5 kilometres from Moss Vale's town centre.The energy generated would be used to run its existing data centre and two more it has planned for the future.The largest power plant would generate 673 MW, enough to run 70,000 homes across a day.More than 200 people gathered on the site where a large gas-fired power plant is planned to run data centre in Moss Vale. (ABC Illawarra: Penny Burfitt)Wingecarribee Shire councillor Heather Champion organised a protest last week that attracted about 200 people on a cold and wet Friday morning."People are really shocked that this is a private Sydney-based company that is building this gas plant solely to power their data campus," she said."People are worried about the health impacts of all the particulate that's going into the air, they're worried about the way that it will lock in heavy industry in the Highlands, and they're worried about the emissions as well."The first and smallest of three data centres planned for Cloud Carrier's Moss Vale site is already up and running. (Supplied: Cloud Carrier)Nakar Property declined to comment because one of the much smaller gas plants is currently being considered in the Land and Environment Court.It previously told the ABC that emissions would be treated to reduce the plant's pollutants to well below the NSW Environment Protection Authority's limits for the area.The company has also defended its decision to submit separate development applications for different parts of the project, saying the evolving nature of AI computing meant energy needs had evolved.Nathalie Swainston says she is concerned about fossil fuels being used for data centres. (ABC Illawarra: Penny Burfitt)Local woman Nathalie Swainston said she was concerned about the impact on the broader environment. "I'm devastated that this is even possible," she said."I'm really worried about the climate impacts of a huge gas plant when we're supposed to be moving away from fossil fuels."'Setting a precedent'Kirstine McKay, from clean-energy group Win Zero, said the development would play a role in determining how other data centres across the state would be powered."If they approve this, everyone will be affected because we're setting a precedent about how things are going to be fuelled," she said."It's really important that the government sets very clear parameters … we need to say that [data centres] need to be 100 per cent run on renewable energy."Kirstine McKay says the development could set a precedent for the rest of the country. (ABC Illawarra: Penny Burfitt)NSW has 90 data centres currently running and more than a dozen in the planning pipeline.Treasurer Daniel Moohkey has previously described NSW as "a premium destination for data centres".Their proliferation and the large amounts of energy and water they use is the subject of a NSW parliamentary inquiry that heard from the local council about the Moss Vale proposal on Friday.Director of Communities and Place Michael McCabe told the inquiry the development seemed at odds with the council's climate action plan, which is aiming for net zero in the community."I would say based on the … reliance on fossil fuels by the proponent, it's going in the opposite direction," he said.Staged developmentThe protest was held directly before the on-site Land and Environment Court conciliation conference considering the development application (DA) for the 16 MW power plant on the site.Councillor Heather Champion organised the gathering independently of council. (ABC Illawarra: Penny Burfitt)The DA was submitted to the Wingecarribee Shire Council in 2025 and Nakar Property took the matter to the court after council failed to decide within the allocated time frame.A similarly sized gas plant has already been approved for the site following the same court process, while the largest gas plant is being considered through the state significant development planning pathway due to its size.Moss Vale local Will McCarthy told the court the community had been subject to "development by stealth" and urged the court to take the entirety of the planned development into consideration."These developments are broken into small pieces to push them through," he told Commissioner Emma Washington.Ros Murphy's family has farmed the neighbouring land for 60 years. (ABC Illawarra: Penny Burfitt)Neighbouring farmer Ros Murphy told the court her family had reared breeders, calves, bulls and horses for more than 60 years on land that adjoins the data campus.She said the potential impact of pollution could affect the farm’s viability."I'm really concerned we're not going to be able to sell cattle because of the strictness at the meatworks," Ms Murphy said."Personally, it's going to be a disaster for us."Southern Highlands residents say they are concerned about the impact of the development on local agriculture, tourism and emissions targets. (ABC Illawarra: Penny Burfitt)Wingecarribee Council said the Land and Environment Court matter was continuing, with an outcome expected next month.The minister for planning and the minister for climate, energy, environment and water have been contacted for comment.