Modern electricity grids are designed as centralized systems where electricity is typically generated at large-scale power plants and then sent through long-distance transmission lines before being distributed to consumers. The model is based on Nikola Tesla's alternating currents theory, which provided an effective way to move electricity over long distances through transmission lines. The competing technology at the time was Thomas Edison's direct current, which lacked a reliable long-distance transmission method, a problem newer technology has since resolved. As a result, we have large power grids that operate in a predictable manner: Power is generated at a central station and is sent through high-voltage transmission lines to a substation closer to consumers, where the voltage is lowered. The electricity then travels across lower-voltage lines to transformers, which convert it to an even lower voltage before it is delivered to households and businesses.