The document summarizes the development and current state of Russia's power sector by decade from the 1920s to the 2000s. It describes key events such as the 1920 GOELRO electrification plan, a focus on nuclear power in the 1950s, sector slowdown in the 1980s, economic crisis in the 1990s, and reforms and decentralization of the previously state-owned sector in the 2000s. The regulatory bodies and main companies in electricity generation, transmission, distribution and trading are also outlined for each time period.