Electricity customers are paying for excessive overtime at three of the state's power companies, the NSW auditor-general says.
In his audit of the government-owned electricity sector, Peter Achterstraat says overtime was a significant cost at power distributors Ausgrid, Endeavour Energy and Essential Energy.
Ausgrid paid more than one million hours of overtime last financial year, with 865 workers paid 50 per cent or more of their base salary.
One worker was paid more than $180,000 in overtime, almost double their $97,000 salary.
At Essential Energy the number of those earning 50 per cent or more of their salary was 200, and at Endeavour, 34.
"Excessive overtime is not good for employees' health and it is not good for the customer's wallet," Mr Achterstraat told reporters in Sydney on Wednesday.
"It may well be that the distributors could re-look at the work practises that were introduced some time ago, to see if they're still relevant for 2012."
Mr Achterstraat also urged the three distributors and transmission company TransGrid to avoid so-called gold-plating of the electricity network, which has been one of the major causes of the 80 per cent increase in prices over the past five years.
He said while wholesale prices had decreased, retail prices had increased, partly because of excessive spending on poles and wires.
"The wholesale prices are down, down, down, but the retail prices are up, up, up," he said.
"One of the reasons the retail prices are up is because there is more expenditure on the poles and wires.
"To avoid criticism of gold plating the network, TransGrid and the distributors ... must ensure their capital expenditure programs are efficient and prudent."
The audit also confirmed the after tax profits for the state's seven power corporations rose to $1.2 billion in 2011-12, up from $1.1 billion the previous year.
Contributions to government increased from $1.2 billon to $1.4 billion over the same period, Mr Achterstraat said.