Cleaner burning gas from shale deposits is quickly replacing coal as the preferred feedstock for the country's power plants.
The NZ Super Fund's general manager investments Matt Whineray said responsible investment was a big part of the fund's mandate.
He said the fund carefully weighed environmental factors associated with this kind of investment and that KKR employed a similar approach.
Justin Reizes, who heads up KKR in Australia, said it had been estimated that US$2 trillion was needed to develop the US energy market from 2008 to 2035, which meant there would be substantial investment opportunities.
NZ Super Fund's investments follow extensive research into opportunities in the energy sector by the fund over the past couple of years.
"These new investments will broaden and diversify the fund's current exposure to energy, in line with what is a changing global energy sector," Whineray said.
He said KKR investment was premised on attractive long-term returns in energy and significant market changes including the rapid development of natural gas and unconventional oil assets.
Whineray said the move would allow the fund to be much closer in terms of its control and influence over the investment, as opposed to the more typical passive holding arrangement.
The $25 billion New Zealand Superannuation Fund invests globally in order to help pre-fund New Zealanders' future retirement entitlements.
KKR, formerly known as Kohlberg Kravis Roberts, is a multinational private equity firm.
Since its founding in 1976, KKR has completed a number of landmark transactions including the 1989 leveraged buyout of RJR Nabisco, which at the time was the largest buyout in history.