According to some, Grand Inga would be too large a proportion of the African demand (43.5 GW combined output compared to a load of 63 GW) to be a practical power source without interconnection by a wide area synchronous grid for example, as well as other power grids. Any large-scale failure of the dam, or its connections to the grid, such as the 2009 Brazil and Paraguay blackout (17 GW), or the 2009 Sayano–Shushenskaya power station accident in Siberia (6.4 GW), would plunge large parts of Africa into a power failure with potentially serious consequences. The Siberia failure, for example, had a disastrous effect on local aluminium smelters. By this argument, full utilization requires interconnection with Europe, so that power to Europe can then be back fed to Africa. This increases the stability of both systems and reduces overall costs.