Waikato University associate professor Earl Bardsley said yesterday if anything, the reverse was true.
Prof Bardsley is promoting the idea of pumping Clutha River water from above or below the Roxburgh Dam to an enlarged Lake Onslow high above Roxburgh.
The water would be stored until it was needed to generate electricity when hydro lakes run low.
Contact Energy chairman Robert McDonald told the company’s annual meeting on Wednesday the multibillion-dollar scheme was "fascinating" but "high risk’.
"We need only look across the Tasman to the Snowy Hydro project’s enormous cost overruns.
"We believe there is much smarter technology that can potentially be harnessed in the pursuit of a lower carbon economy in Aotearoa.
"We are concerned that Project Onslow threatens to paralyse investment in renewable energy infrastructure in the meantime."
Prof Bardsley challenged Contact and other electricity companies to explain their other options.
"Those same companies that are going against Onslow should be asked how they would intend to handle the dry years in the future when we have an electrified economy with electric industrial heating and electric cars.
"They haven’t offered any solution at all, except maybe store gas ... or keep on burning coal."
Contact Energy deputy chief executive James Kilty responded late yesterday and said there were potentially "cheaper, lower risk and less intrusive options" worth exploring, including "flexible hydrogen production and demand flexibility".
Prof Bardsley said Onslow would stabilise prices and make it "more favourable" to establish wind farms.
"If we just keep on building wind farms, without being able to buffer the fluctuations, we run the risk of grid instability.
"So having a lot of pumped storage on hand, enables you to go ahead and build more wind than you otherwise could have done."
He took issue with suggestions a report some years ago on his 2005 proposal for Onslow dismissed the plan as too expensive.
Prof Bardsley said "just for fun" he had proposed a scheme more than twice the size of the 5000 GWh scheme being investigated by the Government.
"It was a whopper. It went up to 12,000 GWh, and it created a huge lake.
"But that report also said, however, a smaller scheme may well be viable."
Prof Bardsley said the electricity companies’ lack of enthusiasm for the Onslow scheme was because it would reduce electricity prices.
He suggested Contact get on board the scheme because it could be designed to boost generation from the company’s Roxburgh Dam.
The Government is spending $30million investigating the business case for the scheme with the possibility of spending a further $70million on engineering design and preliminary field work.
