Domestic energy involves the production and consumption of heat, light, and power for a variety of activities. Heat provides space and water heating as well as cooking. Light, both artificial and natural, is necessary for indoor activities. Power is necessary for moving water, transporting people, fuel, and goods, and for numerous other domestic activities, including building and cultivation. For much of human history, energy came from just two sources: the sun and musclepower, both human and animal. At some point, fire became domesticated and over time became the largest and today, including its form of electricity, almost the only source of domestic energy. At the beginning of time, domestic energy was rather crude but generally uniform. Today it remains virtually unchanged in some areas, intensely sophisticated in others, and by no standard uniform. Even advanced developed cultures with similar living standards use vastly different...