Nine climate protesters are preparing to spend a second night 600ft up the chimney of one of Britain's largest power stations in defiance of a court injunction.

The climate protest camp at Didcot as seen from the air. (Photograph: Neal Veglio/manwithamicrophone.blogspot.com) But 13 others, who broke into Didcot A power station in Oxfordshire early on Monday morning, have been arrested and removed from the coal conveyor belt at the station, which is owned by RWE npower.

"They have been served an injunction but are refusing to come down and are therefore in contempt of court," said a spokesman for the protesters. He added that the injunctions forbade them from entering Oxfordshire. The protesters say they plan to stay up the chimney for a week.

The protesters, who have occupied a room and pitched tents on top of the chimney, were last night celebrating their victory in forcing the power company to switch from burning coal to gas during their occupation. The 2,000MW power station normally emits more than 5m tonnes of CO2 a year; natural gas is considerably cleaner than coal.

The court injunctions are likely to impact seriously on at least two of the protesters who are both students at Oxford University. "We can stay for as long as we can," said Amy Johnson, one of the activists.

The protesters, who met at Climate Camp in London this year, said they had targeted Didcot because RWE npower is planning to build as many as 30 new coal-fired power stations across Europe, including two in Britain.