Life Flight operations manager Dave Greenberg said the Westpac rescue helicopter arrived at the scene around 9am. Co-workers were performing CPR on the one of the men, but he was pronounced dead by a Wellington Free Ambulance paramedic.
Mr Greenberg said the other man, a 34-year-old Filipino, had sustained chest and leg injuries, and was flown to Wellington Hospital in a serious condition.
He said the men had been in a cherry-picker basket about 8-10 metres in the air when it toppled over.
Police are at the scene, investigating the accident and talking to around 12 witnesses.
Meridian has 62 turbines at the site, each generating 2.3 megawatts.