TVA was created to serve the public and improve life in the Tennessee Valley region by providing energy, protecting the environment, and promoting economic development. It generates reliable, low-cost power sold through local power companies, safeguards the environment, manages the Tennessee River watershed, and supports economic activity aimed at creating high-paying jobs in the region. TVA has also evolved in its role as a steward of the region by producing power with facilities intended to make the air cleaner, reducing reliance on coal plants, using nuclear and gas-powered plants with lower emissions, working with power distributors and directly served industries on energy efficiency, and including renewable sources such as the hydrological system, sun, wind, and methane gas in its generation portfolio.