Helios presented its application at the first day of a resource consent hearing in Ranfurly yesterday.
The company was planning to build a 300MW solar farm which would include some 550,810 solar panels mounted on tracking arrays.
It would cover 23% of the 665ha site leased by the company.
Commissioner Gary Rae asked why the site had to be so large.
He had visited the site and at the hearing said it was the largest piece of land for an application he had seen in his 40 years of being a commissioner.
Helios co-owner and managing director Jeffrey Schlichting said there were fixed costs when building a solar farm and it had to be financially viable.
To connect with the nearby Naseby sub-station it would take significant costs.
He said it would not matter if the company was producing 10MW or 300MW, the costs would be identical.
With the length of a consent it had to be economically viable.
"If we have a smaller solar farm the power returns would be smaller and it would be economically challenging."
He said the project would not be getting the sky-high prices seen last year when the supply of power was in short supply and would be selling the power generated from the solar panels to a gentailor.
Mr Schlichting said he had worked for 35 years in the wind and solar power industry.
He had been involved in projects in North America, Africa and New Zealand in that time.
He said the company’s development site in Maniototo was the best site for a solar farm in the country and the project was a significant investment in renewable energy.
New Zealand has a goal to reach net-zero greenhouse gas emissions by 2050.
A key part of this plan was to double the amount of renewable energy used by 2050.
This project would help reach this goal but plants of at least this size needed to be built every year, he said.
The site had many advantages, he said. It was on flat land, had good geology, was close to the connection to the national grid and the panels could lie flat.
Solar power had many advantages. Much of the power could be used in summer which would allow reduced use of hydro power in summer. It could be deployed quickly and was safe and quiet.
The applicant had removed the battery energy-storage system component of its proposal.
Mr Schlichting said that was in response to feedback he had received from submitters about fire risk.
The issue of a bond being lodged to safeguard the community was raised by some submitters but that idea was rejected by the applicant yesterday.
Joining Mr Rae at the hearing are independent commissioners Louise Taylor (chairwoman) and Ros Day-Cleavin.
Helios council Daniel Minhinnick said, in reply to a question from Ms Day-Cleavin about a bond, that it was incredibly rare for a bond to be required.
"A sweep of conditions and the powers a council has can make sure the conditions are complied with," he said.
He said they were more common in large infrastructure projects but not one of the size the company was proposing.
Submitters were due to be heard today.
The hearing was set to finish tomorrow but may finish today.
