Sales inquiries for generators and batteries have surged as fears mount among NSW households and businesses of power cuts this week after a spate of outages at coal power plants and a pre-summer heatwave.

Generator and battery retailer SmartChannel has seen a 60 per cent surge in demand for its Outbax generators in the past three months and an even bigger jump in inquiries for VoltX home batteries, reflecting the increasing anxiety among residents seeking reliable back-up power solutions.