A protest has been held in Redcar against a government proposal to test the potential for heating homes with hydrogen.
Some 2,000 properties would be part of a "hydrogen village", looking at green alternatives to gas boilers.
But people living there are "angry" there has not been a local vote.
The government said strong community support would be "a critical factor" in approving a trial and it is due to make a decision soon.
If approved, Northern Gas Networks (NGN) would switch the properties from natural gas to hydrogen heating.
Plans for a similar trial near Ellesmere Port, Cheshire, were scrapped earlier this year in the face of local opposition.
Safety is understood to be the primary concern, with more than 500 people signing a petition calling for a vote.
Dawn Campbell, a landlady, told the BBC: "The effect on people's mental health has been appalling, people are worried whether it's going to go ahead and it's being forced."
"We are being treated like Guinea Pigs. There's a reasonably high percentage who don't know because they are not being told specifics."
Calvin Lawson, regional campaigns organiser for Friends of the Earth, said there was a "clear and organised opposition to this trial that cannot be ignored".
A Department for Energy Security and Net Zero spokesperson said a decision would be made later this year.
"We have always said community support would be at the centre of any decision," they added.
"Before any trials go ahead, the Health and Safety Executive will need to be satisfied it will run safely and we have committed to ensuring consumers are protected before, during and after any trial."
A survey suggested 76% of residents were in favour, with another 19% indifferent or undecided.
An NGN spokesperson said the firm had "worked tirelessly" over the last 18 months to "engage with and reassure" residents and businesses.
"Our door is always open, and we continue to actively encourage anyone with questions or reservations to come and speak to us at our 'Hydrogen Hub' on the High Street."
It said it was planning a public meeting in December and is working with the government about the arrangements.