TrustPower has refunded former Waikouaiti Beach Motor Camp manager Andrew Cleghorn $13,000 after admitting it had overcharged him.
Managers of the camp before Mr Cleghorn were refunded $5300.
After six years of big power bills, Mr Cleghorn investigated power charges at the camp, just before relinquishing the lease.
He contacted similar-sized camping grounds, and found his bills were "considerably higher" than theirs.
An independent inspector identified reasons for the extra charges, establishing the camp's meter was charging units of power used at several times the correct rate.
Over six years the camp was overcharged by about $13,000.
Mr Cleghorn asked if he would receive interest on the amount he had overpaid, but TrustPower said it would not, as it could not be shown he would have earned interest on it.
In November, Mr Cleghorn was reimbursed about $13,000, TrustPower community relations manager Graeme Purches said.
The managers before Mr Cleghorn, Barry and Alison Smith, of Dunedin, were also reimbursed - $5300 - after being overcharged.
"There are a whole raft of reasons why it could have occurred . . . in this case a multiplier for the meter was wrong," Mr Purches said.
There were a few cases like Mr Cleghorn's each year, but it was more common for power users to be undercharged.
TrustPower most likely "inherited" the charging anomaly from Otago Power, which it bought in 1999, Mr Purches said.
