Welcome back mechanically here. Did you know that the world's first commercial power plant was based on cogeneration and belonged to the Thomas Edison? This makes us wonder, what is cogeneration? Before we jump in, check out the previous part of this series to learn about what the Rankine and Carnot cycles are. First, let's clear out the concept of ideal reheat Rankine cycle. A Rankine cycle consists of a pump, boiler, a turbine and a condenser working in sequential order to produce the power. In a reheat Rankine cycle, a low pressure turbine is added to the mixture and the steam from the exhaust of high pressure turbine is recycled into the boiler and sent to the intake of low pressure turbine, which then generates power. Cogeneration or combined heat and power CHP for short is a use of a heat engine or power station to generate electricity and useful heat at the same time. Unlike the reheat Rankine cycle, which uses a condenser to condense the steam to liquid, cogeneration uses a process heater to transfer the heat as required. Cogeneration is more thermally efficient use of fuel than producing process heat alone because in electricity production, some energy must be rejected as waste heat. But when combined with cogeneration, some of this thermal energy is put to good use. Hence, we first saw what the reheat Rankine cycle is and then went on to find out what cogeneration is. So, here are the top mechanical ears of our last videos. In the next episode of Mechanical ear, find out what the auto cycle is.