Low Head Schemes

Pandy Mill

Hydro Schemes were approached by the owner of the old Pandy Mill (North Wales) with a view to develop a 100 kW scheme. Planning permission, abstraction licences and all other permits and licenses were successfully obtained by Hydro Schemes. Construction included removal of rock, reinforced concreting works for the weir and powerhouse and installation of the archimedes screw.

Years in operation: 8 +

Annual output: 500,000 kWh

Maximum output: 100 kW

Archimedes screw under construction at Pandy Mill


This development involved an installation of an archimedes screw to replace an old ‘overshot’ type turbine- the rationale being that archimedes screws are significantly more efficient and ‘ fish friendly.’ Civil engineering work included: reinforced concreting, access tracks, cranage, installation and commissioning.

Years in operation: 7 +

Annual output: 250,000 kWh

Maximum output: 50 kW

Archimedes screw installation at Ponterwyd


Aberdulais hydro incorporated a large 9-metre-long screw with a diameter of 1.2 metres. The development involved a large amount of excavation to facilitate the position of the screw. All excavated materials were reused to form access roads to the site, minimising imported material and the overall carbon footprint of the development.

Years in operation: 4 +

Annual output: 450,000 kWh

Maximum output: 100 kW