There are calls for the Welsh Government to look again at where windfarms can be sited.
Russell George, Conservative AM for Montgomeryshire, wants a review over a policy which earmarked seven areas of mid and south Wales as potential sites.
He was speaking after the Welsh Government announced plans to limit the number of windfarm developments.
Mr George said the policy - known as Tan 8 - is no longer "fit for purpose".
First Minister Carwyn Jones said his administration "would not support the construction of large pylons" in mid Wales, and wants previous guidelines for the number of windfarms to become maximum limits.
He said he would ask for powers to be devolved from Westminster to ensure it happens.
The announcement has been welcomed by campaigners fighting plans for a 19-acre substation and dozens of pylons in mid Wales to serve new windfarms.
Mr George told BBC Radio Wales that Tan 8, which dates back to 2005, effectively encouraged windfarm developers to submit applications for the areas it identified.
He said there would be an opposition-led debate about the policy in the Senedd on Wednesday.
"We've got to ask the first minister to concede that Tan 8 is not fit for purpose and there needs to be an urgent review," he said.
"I think Carwyn is saying himself when we introduced this in the first place we did not quite realise it would mean this.
"I think it was short sighted back in 2005 ...not to anticipate the associated pylons and electricity substation that would be needed to support such large scale windfarm developments."
On Friday Mr Jones said the number of applications and declarations of interest from developers was higher than anticipated, leading to proposals for major overhead grid infrastructure.
He said: "The Welsh Government believes this level of development is unacceptable in view of its wider impacts on the local area."
He said the Tan 8 "capacities should be regarded as upper limits".
Overall responsibility for large-scale energy generation rests with the UK Government.
Mr Jones said he hoped the UK Government would "respect" his announcement and "not allow proliferation when they take decisions on individual projects in Wales".
He added: "My government would not support the construction of large pylons in mid Wales and my ministers are pressing this case with National Grid Transmission and with Ofgem.
"This situation amply illustrates why consents for major energy infrastructure projects must be devolved to Wales."