The national grid operator is planning to spend nearly $5 billion on the network between 2025 and 2030.
The spend includes capital expenditure of $2.25 billion - 32 per cent higher than the current five-year period.
Another half-a-billion-dollars is earmarked for reliability, resilience, and enhancement.
The changes will add around $7 a month to the average power bill.
Transpower chief executive Alison Andrew spoke to Ingrid Hipkiss.
