Power has been restored in Abbots Langley High Street.
Four businesses were affected by the power outage from 3.25pm, after a fault with UK Power Networks "low voltage electricity network".
UK Power Networks confirmed that power was restored to the affected businesses by 4.45pm.
Jennifer Davis, external communications officer at UK Power Networks said: "Our engineers were on site within half an hour of the fault, with all supplies returned to normal by 4.45pm.
"We realise how difficult it can be to be without power and apologise for any inconvenience."