First Hydro Company Home > Power Stations > About Pumped Storage About Pumped Storage Pumped storage hydro-electricity works on a very simple principle. Two reservoirs at different altitudes are required. When the water is released, from the upper reservoir, energy is created by the downflow which is directed through high-pressure shafts, linked to turbines. In turn, the turbines power the generators to create electricity. Water is pumped back to the upper reservoir by linking a pump shaft to the turbine shaft, using a motor to drive the pump. The pump motors are powered by electricity from the National Grid - the process usually takes place overnight when national electricity demand is at its lowest A dynamic response - Dinorwig's six generating units can achieve maximum output, from zero, within 16 seconds. Pump storage generation offers a critical back-up facility during periods of excessive demand on the national grid system. Contact Dinorwig Power Station Llanberis Caernarfon Gwynedd LL55 4TY 01286 870166 info@fhc.co.uk www.fhc.co.uk Ffestiniog Power Station Tan-y-Grisiau Blaenau Ffestiniog Gwynedd LL41 3TP 01766 830465 info@fhc.co.uk www.fhc.co.uk Manage Cookies engie.co.uk engie.com © FHC 2021 Cookies are used to make this website work and to enhance your experience. To learn more about the types of cookies this website uses, see our Cookie Policy. You can provide consent by clicking the "I Consent" button or by canceling this cookie notice. I ConsentManage Cookies Cookies are used to make this website work and to enhance your experience. To learn more about the types of cookies this website uses, see our Cookie Policy. We need your consent to use marketing cookies. Marketing cookies are used to track visitors across websites. Please select the checkbox below to indicate your consent. I consent I do not consent Save Preferences Your cookie preferences have been saved