The Prime Minister Jacinda Ardern announced the aid on the fringes of the Asia Pacific Economic Corporation leaders summit in PNG's capital Port Moresby.
New Zealand will join the United States, Australia and Japan in a 1-point-17 billion US dollar project to expand electricity coverage to about three quarters of PNG's population.
NewZealand's contribution is about 14-million US dollars.
Thie weekend's APEC leaders summit has so far been dominated by tension between the US and China whose leaders swapped barbs regarding issues such as trade in their speeches yesterday.
However, several countries have used the summit to announce major aid and development projects in PNG.
Ms Ardern said her government would also give close to 7 million US dollars for immunisation campaigns in PNG, particularly for polio which has re-emerged in the country.
The New Zealand leader also officially open the newly constructed and redeveloped Gordons Market today ahead - the redevelopment was co-funded by New Zealand at a cost of 20 million US dollars.
While in Moresby, Ms Ardern has been transported around in a Toyota vehicle, after earlier announcing she wouldn't be riding in the Massarati vehicles which PNG's government controversially imported for the summit.
The usually busy city of Port Moresby has become like a ghost town in the last couple of days due to restrictive security measures for the APEC summit.
A massive multi-national security operation is underway with about 4,000 military personnel, about half of whom are foreign, in the city duiring the summit.
However a number of Moresby's main freeways have been closed off and police have been out in full force questioning any vehicles traveling near the restricted zone.
RNZ Pacific reporter Melvin Levongo said that local markets had been mainly empty, public transport has been shut down for most of the city routes, while hospitals were only attending emergency cases.
Local PNG media have been restricted from covering the arrival of world leaders by the staff of Port Moresby's international airport staff.
Senior PNG journalists have expressed disappointment that international media were allowed to cover foreign leaders arriving in PNG, while they were not.
PNG's National Airport Corporation did not respond to questions about why local media were barred from access to the airport during the arrivals of leaders.
However local and international media were barred from attending the Chinese President Xi Jinping's meeting with Pacific Islands leaders in Moresby on Friday.
Despite being accredited and invited to cover the event, Chinese officials blocked access to all media apart from those from China's state-run agencies.