South Africa’s national grid nearly collapsed in early 2008, forcing mines and smelters to shut for days and costing Africa’s biggest economy billions of dollars in lost output.

Power utility Eskom has since said it would invest up to 460 billion rand ($66 billion) in new power plants to plug the shortfall and meet fast-rising demand from industries and residential consumers, but analysts say this may not be enough.

“It may be a matter of too little too late,” said Ross Bruton, an energy analyst at consultancy Frost & Sullivan.

The potential of power cuts is enough to support prices of the white metal, chiefly used in diesel auto-catalysts.

“The picture painted by Eskom is not a favourable one and it should definitely keep prices up,” said Sasha Naryshkine, an analyst at Vestact.

Spot platinum was at $1,771.50 an ounce by 0715 GMT, having risen by a 0.2 percent so far this year, while palladium was trading at $730 an ounce, and has fallen by nearly 9 percent in 2011, in sharp contrast to the 50-percent year-to-date rise posted at this time last year.

Analysts also said there is some restocking taking place to boost stockpiles because of a threat of supply disruptions.

Eskom, which plans to bring new stations on line from 2013, has said it will operate on a razor-thin margin for the next few years and any slip-up could mean lights out.

“We can’t guarantee there will be no load shedding,” said spokeswoman Hilary Joffe, referring to power cuts.

She said the utility would not discourage miners from expanding, but the timing of new projects may depend on when Eskom is able to add the needed megawatts to the grid.

Each new deal is also bound by the condition that miners agree to reduce demand in the event of an emergency, she added.

This may mean mining projects being delayed if Eskom’s expansion suffers any setbacks. Only last week construction of its two new plants was halted following protests.

Impala Platinum, the world’s second-largest producer, said the crunch was unlikely to affect its expansion.

“It’s more about what will the power situation be in 5 to 10 years,” Chief Executive David Brown said. “We certainly believe that in the 5-10 year period it should be adequate.”

But the chamber of mines, an industry body, said the lack of supply for new projects would hurt development of new mines.

Junior miner Northam Platinum says it will decide on a second-phase expansion of its planned Booysendal mine once it can receive certainty about supply from Eskom.

Since the 2008 crisis, miners and other industries have been asked to cut their demand voluntarily by up to 10 percent and there is discussion about making the scheme mandatory.

The most imminent test for Eskom will come during a peak demand season in South Africa’s winter from June to August. Although most miners seem to be keeping a brave face about 2012, analysts say the risk of power cuts has increased.

“If we squeeze through this year, we probably won’t make it through next year,” said Leon Esterhuizen, an analyst at RBC Capital Markets. The 2008 crisis and rising tariffs have forced firms to make their mines more efficient, some cutting demand by 30 percent.

Some are investing in partial power generation to limit their dependence on the grid and sharp increases in tariffs by co-generating power during industrial process at their plants.

“If you are a small producer and you are shallow, that’s an obvious answer. But for the big guys, it’s impossible. You can’t put up generators to run your vertical shafts, your smelters,” said Esterhuizen.

Analysts say Eskom may hesitate to cut power to mines, which could further strain an unemployment rate of 25 percent. Mining accounted for about 8 percent of South Africa’s economy in 2009.

While the risk of power cuts is supporting the platinum price, producers are battling many headwinds, including rising power and wage costs, a strong rand and stricter safety rules.

Eskom, once one of the world’s lowest-cost electricity producers, was granted three years of 25 percent rises in power tariffs and may apply for two more similar increases.

Only from 2016 are tariffs expected to rise in line with inflation, the power regulator said.

Walter de Wet, a Standard Bank analyst, said power costs to produce 1 ounce of platinum as proportion of total costs could double to 16 percent between 2009/13.

“We estimate... that the marginal producer will need a platinum price of $2,300 (an ounce) to break even on a cash-cost basis by the end of 2013,” he said in a recent note.

While gold miners seek to expand elsewhere, platinum producers are bound to South Africa, home to four-fifths of the metal’s reserves.

A study last year by U.S. investment bank Citi valued its platinum deposits at nearly $2.3 trillion.The second-largest reserves can be found in neighbouring Zimbabwe, where power supply is even more constrained and where political uncertainties increase the investment risk.