National Grid will unveil its plans today for the connection for new windfarms in Mid Wales.
The details to be revealed include where the windfarm substation will be built and the route that the pylons will be placed on throughout Powys and Shropshire.
National Grid said it had made the decision over the preferred connection plan for the windfarm after 'extensive consultation' with local communities and specialists.
The power network also said it had 'carried out detailed assessments to look at the potential effects of the proposals on the landscape, environment, heritage, and local communities.'
The National Grid had previously identified two possible locations for the substation- either Abermule near Newtown or in Cefn Coch near Llanfair Caereinion.
Several energy companies have submitted proposals for windfarms in Mid Wales, which has been identified by the Welsh Government as a key location for on-shore wind generation.
Two such proposals are RWE's 50-turbine Carnedd Wen Windfarm near Welsphool, and RES' 34-turbine farm in Llanbrynmair.
National Grid must be able to connect any future wind farms such as these to the national electricity network.
This would mean building a substation to convert the energy created by wind turbines into electricity, and installing a network of pylons to carry the power generated.
But like many regions in the UK faced with the prospect of nearby windfarms, there is fierce local opposition to the proposals in Mid Wales.
Protest groups argue that new wind turbines and the pylons needed for them under National Grid's plans, would impact badly upon the physical appearance of the area and would discourage tourism.
They also claim that Mid Wales' roads would not be able to cope with the burden of transporting the huge turbines.
Local opposition also
RWE has offered to spend up to 18 million pounds over 20 years on projects in local communities if its windfarm project in Carnedd Wen goes ahead.
But this offer hasn't been enough to satisfy locals, who travelled to the steps of the Senedd in May last year to protest against the farms.
Powys County Council rejected planning three planning applications for windfarms in Mid Wales in March, including the one for Carnedd Wen.
Despite the Council's strong statement against wind farms in he area, the ultimate power to decide whether the windfarms will go ahead in Mid Wales lie with Westminster and the Department of Energy and Climate Change (DECC).
It will be some time before a decision is made on the Powys windfarm proposals.
DECC said it expected a Pre-Inquiry meeting to take place in Spring 2013, with the full Inquiry not starting until later next year.