Contact's Clutha hydro project manager, Neil Gillespie, told a recent business forum in Alexandra that the energy company was still considering community issues and refining the cost of the four hydro scheme options for development on the river.
Dams are proposed at Luggate, Queensberry, Tuapeka Mouth and Beaumont.
No decision had been made on the preferred option or options.
"The cost is one of the significant issues, and the return for that cost," he said.
Cost estimates ranged from $350 million to $1.5 billion.
"There's a long construction time, so a long lead-in period before you make any money and we're still refining our costs to see if the projects are viable," Mr Gillespie said at the Otago Chamber of Commerce forum which aimed to give an overview of Central Otago in the year 2020.
"The key thing is under the current estimates, the price of power would have to go up to make the projects viable and that's about as palatable as a lot of other things, like a rates increase."
After the forum, Mr Gillespie said the comment about power prices related to any new generation schemes, not just the hydro schemes.
Contact Energy communications adviser Louise Griffin said any form of new electricity generation was expensive to construct and power prices would need to increase to make any new generation viable.
"Growing demand for electricity means we will need new power stations, which are more expensive to build and run, than existing power stations," she said.
New Zealand electricity prices reflected the cost of providing electricity and the cost of building new generation to meet this country's demand for power in the future.
A Contact Energy booklet on electricity prices said the New Zealand electricity market was unique in that most generation was from renewable sources and New Zealand was an isolated market with no means of importing or exporting electricity.
New power stations were more expensive to run than existing power stations, Contact said in the booklet.
The cost of energy for future electricity generation options was rising and the energy component in tariffs would have to increase to make new hydro and wind generation schemes viable.
Mr Gillespie told the forum that new hydro generation on the Clutha would meet the future demand for power and would complement wind-generated power schemes - "when the wind is blowing you can store water and not use your hydro resource".
Regardless of where any new generation scheme was located, or what it was, there would be detractors, he said.
However, with the growth in the region, there would continue to be a growing demand for electricity, which had to be met.
