  Robust synchronization is indispensable for stable operation of a power grid.
Recently, it has been reported that a large number of decentralized generators,
rather than a small number of large power plants, provide enhanced
synchronization together with greater robustness against structural failures.
In this paper, we systematically control the spatial uniformity of the
geographical distribution of generators, and conclude that the more uniformly
generators are distributed, the more enhanced synchronization occurs. In the
presence of temporal failures of power sources, we observe that spatial
uniformity helps the power grid to recover stationarity in a shorter time. We
also discuss practical implications of our results in designing the structure
of a power-grid network.
