Two wind farms will not go ahead after officials rejected the proposals which would have seen 29 turbines erected.
Planners had been expected to approve the projects in Denbighshire at Llyn Brenig, near Cerrigydrudion, Conwy, and at Gorsedd Bran in Clocaenog Forest.
But at a meeting to decide the matter, 18 councillors voted against the proposals, with just four in favour. There were two abstentions.
A wind farm with 25 turbines already operates in the Clocaenog Forest.
Members of Denbighshire Council's planning committee met on Wednesday to vote on the two proposals.
Windpower Wales wanted to build 16 wind turbines on land to the east of Llyn Brenig.
A separate application was made by Tegni Cymru Cyf, which wanted to build 13 turbines at nearby Gorsedd Bran.
Some of the reasons given for refusal included the risk of flooding due to deforestation in the Clocaenog forest.
Councillors were also concerned about the impact on a nearby area of outstanding natural beauty, noise levels and the potential impact on tourism and local economy.