Thermodynamics and its role in helping to power our lives are explored in this 1976 CHRISTMAS LECTURE presented by chemist Sir George Porter. Porter takes the audience through the laws of thermodynamics with a series of demos that explain how they work in real-life settings, such as a heat pump for a refrigerator and how to warm a swimming pool using sunlight and black screens. George uses models to introduce different types of renewable energy sources like wind and wave power.