This lecture covers the motivation behind electricity markets, the definition of Levelised Cost of Electricity (LCOE), its real-world application, the energy crisis, and climate policies. It discusses the LCOE values of various energy technologies, the impact of subsidies on LCOE, and the intrinsic and extrinsic limitations of LCOE calculations. The lecture also explores the uncertainties in LCOE, optimal system configurations, and the challenges faced by renewable energy integration. Additionally, it addresses the market value of electricity, system perspectives in LCOE calculations, and the importance of designing an economical overall energy system.