Why do transmission and distribution (T&D) losses occur, and how are they mitigated?

• A. Resistance and heat cause losses; high voltage transmission reduces current and losses; upgrades reduce losses.
• B. Losses occur due to incorrect generation scheduling; no mitigation.
• C. Losses are only from theft; improved security eliminates them.
• D. Losses occur due to energy storage inefficiency; increasing storage increases losses.

Answer: (A)

T&D losses come from resistance in the wires and inefficiencies in transformers. When current flows through conductors, some energy is lost as heat due to I^2R losses in the lines and transformer windings. For the same amount of power delivered, increasing the transmission voltage lowers the current, and since the losses scale with the square of the current, these losses drop significantly. Upgrading equipment—using better conductors, thicker or lower-resistance lines, more efficient transformers, and improved grid infrastructure—reduces resistance and other losses, further cutting wasted energy. Other issues like scheduling mistakes or theft don’t address the fundamental heat losses in the conductors and transformers, so they don’t explain the main mechanism or the mitigation strategy as directly.