Update - 9.54pm: Work to restore power to 2,657 properties in Cumbria - and thousands more in Lancashire, will resume at 8am tomorrow.
More mobile generators have been secured from across the UK which will be connected throughout the night.
Mark Williamson, operations director for Electricity North West, said: “Unfortunately power was lost to customers in Lancaster and the surrounding areas this evening due to unforeseen flood damage at our substation.
“We plan to begin to restore supplies from the substation tomorrow morning and we would like to thank our customers for their patience and support during what continues to be an enormously challenging time for everyone involved.”
A statement reads: "19,000 customers in Lancaster are still being supplied by generators that were mobilised last night. Further generators will be mobilised tonight and all generators will be refuelled when required.
"2,657 properties remain without power in Cumbria, where floodwater is restricting access for Electricity North West teams. We will provide a further update about Cumbria at 10pm.
"Flood defences at Kendal and Carlisle substations have held, protecting supplies to 110,000 homes.
"Vulnerable customers, including some older or disabled people, or those with a medical dependency on electricity, can also sign up to the Priority Services Register here or contact Electricity North West on 0800 195 4141."
