Energy conservation is the effort to reduce wasteful energy consumption by using fewer energy services. This can be done by using energy more effectively (using less and better sources of energy for continuous service) or changing one's behavior to use less and better source of service (for example, by driving vehicles which consume renewable energy or energy with more efficiency). Energy conservation can be achieved through efficient energy use, which has some advantages, including a reduction in greenhouse gas emissions and a smaller carbon footprint, as well as cost, water, and energy savings.

Green engineering practices improve the life cycle of the components of machines which convert energy from one form into another.

Energy can be conserved by reducing waste and losses, improving efficiency through technological upgrades, improving operations and maintenance, changing users' behaviors through user profiling or user activities, monitoring appliances, shifting load to off-peak hours, and providing energy-saving recommendations. Observing appliance usage, establishing an energy usage profile, and revealing energy consumption patterns in circumstances where energy is used poorly, can pinpoint user habits and behaviors in energy consumption. Appliance energy profiling helps identify inefficient appliances with high energy consumption and energy load. Seasonal variations also greatly influence energy load, as more air-conditioning is used in warmer seasons and heating in colder seasons. Achieving a balance between energy load and user comfort is complex yet essential for energy preservation. On a large scale, a few factors affect energy consumption trends, including political issues, technological developments, economic growth, and environmental concerns.

User behavior has a significant effect on energy conservation. It involves user activity detection, profiling, and appliance interaction behaviors. User profiling consists of the identification of energy usage patterns of the user and replacing required system settings with automated settings that can be initiated on request. Within user profiling, personal characteristics are instrumental in affecting energy conservation behavior. These characteristics include household income, education, gender, age, and social norms.

User behavior also relies on the impact of personality traits, social norms, and attitudes on energy conservation behavior. Beliefs and attitudes toward a convenient lifestyle, environmentally friendly transport, energy security, and residential location choices affect energy conservation behavior. As a result, energy conservation can be made possible by adopting pro-environmental behavior and energy-efficient systems. Education on approaches to energy conservation can result in wise energy use. The choices made by the users yield energy usage patterns. Rigorous analysis of these usage patterns identifies waste energy patterns, and improving those patterns may reduce significant energy load. Therefore, human behavior is critical to determining the implications of energy conservation measures and solving environmental problems. Substantial energy conservation may be achieved if users' habit loops are modified.

User habits significantly impact energy demand; thus, providing recommendations for improving user habits contributes to energy conservation. Micro-moments are essential in realizing energy consumption patterns and are identified using a variety of sensing units positioned in prominent areas across the home. The micro-moment is an event that changes the state of the appliance from inactive to active and helps in building users' energy consumption profiles according to their activities. Energy conservation can be achieved through user habits by following energy-saving recommendations at micro-moments. Unnecessary energy usage can be decreased by selecting a suitable schedule for appliance operation. Creating an effective scheduling system requires an understanding of user habits regarding appliances.

Many techniques for energy conservation comprise off-peak scheduling, which means operating an appliance in a low-price energy hour. This schedule can be achieved after user habits regarding appliance use are understood. Most energy providers divide the energy tariff into high and low-price hours; therefore, scheduling an appliance to work an off-peak hour will significantly reduce electricity bills.

User activity detection leads to the precise detection of appliances required for an activity. If an appliance is active but not required for a user's current activity, it wastes energy and can be turned off to conserve energy. The precise identification of user activities is necessary to achieve this method of energy conservation.