An analyst says a closure of Tiwai Point would be unlikely to have any significant impact on Meridian Energy.
The New Zealand Stock Exchange commissioned five research companies to look at the state-owned company, which is due to list on the market later this month.
Many analysts have given a stock listing price that's higher than the Government's price cap of $1.60, though the full range is between $1.43 - $1.90.
They say the biggest risk facing potential investors is the Labour-Green policy shaking up the way the electricity market is structured.
Bruce McKay, an analyst at the independent research firm Edison, says if that happens, up to 70 cents could be wiped off Meridian's share price.
But he says estimating what the company is worth today, the value is likely to be lower and the impact may be about 15 cents a share.
Mr McKay says Tiwai Point is unlikely to close but he believes it will have little impact on Meridian, if it does.
He says because Meridian is a low cost generator it will always be able to sell power and the impact of any closure of Tiwai Point would be likely to fall on the more expensive thermal generators.
Mr McKay says Rio Tinto would face $200 million - $300 million environmental exit costs if it were to close the smelter.
He says even if Tiwai was not making a profit, but not making massive losses either, it would be more likely that Rio would keep it open.