The difference, of 61 to 81 gigawatts, is equivalent to three times RusHydro's capacity or six times that of Mosenergo.
The ministry corrected its forecast to show that Russia's overall power capacity should reach 236.8 to 245.1 gigawatts by 2015, depending on various scenarios for power consumption.
The information was in the Audit Chamber's report for January, which looked into the work of the System Operator and the Energy Ministry. A copy was obtained by Vedomosti.
Russia's current power capacity is 211.85 gigawatts, meaning that in the coming five years, at least 25 to 33 gigawatts should be built, not including the replacement of capacity that must be replaced. Overall construction of new units, including replacements, should be 31.2 to 40.9 gigawatts for 2011 to 2015, the Audit Chamber report said.
That is far less than was planned under the main document on the matter, which is frequently referred to as GOELRO-2, after the Soviet plan for the power sector. That plan says that by 2015, the capacity of Russia's stations should be 297.5 to 326.2 gigawatts, with an annual forecast for demand growth of 4.1 percent to 5.2 percent.
Under the revised figures, 60.7 to 81.1 gigawatts less capacity will be needed, not counting replacements. By comparison, the country's largest power generator, RusHydro, has 25.4 gigawatts of capacity. The largest regional generator, Mosenergo, has about 12 gigawatts.
The GOELRO-2 plan was created in 2006 and 2007 and is well out of date, something that officials have repeatedly conceded. Then-Deputy Energy Minister Vyacheslav Sinyugin said last year that the amount of new capacity built by 2015 could be reduced by half or two-thirds, but details had not been released.
The Audit Chamber does not break down the construction requirements by specific generators, although it does offer a valuation based on the type of station.
An Energy Ministry official said the figures were not final and changes to the plan would be ready by the end of May. In June, the government will consider the new draft of the plan.
The ministry official declined to comment on the changes, saying only that the forecast for demand growth would be 2.2 percent to 3.1 percent per year.
The plan is entirely realistic, said Sergei Pikin, director of the Energy Development Foundation. If the pre-crisis demand growth of 3 percent to 4 percent only returns in 2013, then by 2015, the country will need no more than 20 gigawatts of new capacity, he said. The most important thing is modernizing existing plants, which is 20 percent to 30 percent cheaper on average and would reduce costs for consumers, he said.