Customers experienced an average of 1.77 outages over the twelve month period, with an average restoration time of 113 minutes.
"This is well below the targets set by the Commerce Commission and reinforces the impact Unison's investment in a smart network vision."
Unison Group chief executive Ken Sutherland said the company continued to lead the electricity distribution industry.
"Through global technology partnerships, Unison has made its mark both nationally and internationally, driving the adoption of innovative network solutions for our customers."
It was also a positive year for subsidiary companies.
"Unison Contracting Services Limited has had a solid year, and was recently recognised at an industry level for its commitment to a strong safety culture.
"Unison Fibre Ltd has continued its progress in the market - its focus has evolved from building the network to working with retail service providers to encourage customers to connect."
The distribution manufacturing business ETEL had success in securing two large Australian wind farm contracts and consolidated its position in the Australian market.
Hawke's Bay Power Consumers' Trust chairman John Newland said trustees were happy with the result.
"It is very pleasing that the deployment of strategies and technologies over the past few years is delivering such a high level of security of supply to Hawke's Bay's customers," he said.
At the trust's AGM yesterday he also paid tribute to retiring Unison director John Palairet.
An announcement on the amount of dividend paid to individual electricity account holders is yet to be made by the trust. Last year's was a record $150 payout, up from $135 the previous year.