VICTORIA - Auditor general Carol Bellringer says BC Hydro has deferred $5.5 billion in expenses that it plans to recover from ratepayers over time.

Bellringer focused on the deferred expenses in a report released Wednesday about the public utility's use of rate-regulated accounting to control the prices it charges customers.

The report found 29 BC Hydro deferral accounts, of which some will be paid off within two years while others could take 40 years to eliminate, she said.

Bellringer said rate-regulated accounting is used widely across North America, but she cautioned that Hydro has largely overridden the role of the independent B.C. Utilities Commission to regulate rates.

"We think it's important for the people of B.C. and our members of the legislative assembly to better understand rate-regulated accounting in order to appreciate the impact it has on the bottom line for BC Hydro, for government as a whole, for ratepayers and for taxpayers," Bellringer said in a conference call with reporters.

Last June, the B.C. government launched a two-phase review of BC Hydro to find cost savings and look at the direction of the Crown utility.

The review came shortly after a planned government rate freeze was overturned by the utilities commission, which resulted in a three per cent rate increase for customers in April 2018.

Statements from BC Hydro and the provincial government supplied in the report say a key objective of the review due this month is to enhance regulatory oversight of the commission.