High-voltage transmission lines carry high-voltage electricity over long distances, and they are instrumental in delivering electricity to the power grid's distribution networks. These high-voltage power lines carry up to 500,000 volts. A large industrial plant might also require high-voltage lines directly from overhead transmission lines. Without high-voltage transmission lines, the complexity and vulnerability of the power grid become more expensive and difficult to manage. Power is conveyed at a high voltage to increase efficiency by preventing energy loss. Higher voltage means lower current. In turn, lower current decreases resistance loss in conductors. Decreased resistance translates to less lost energy as electricity moves over long distances, making transmission lines an essential part of the power grid. There are two kinds of electrical lines. High-voltage lines carry power from the power plants to substations, often over long distances. From the substation, distribution lines send energy to residential and business consumers. Distribution lines have a much lower voltage.