Energy efficiency may be defined as the ratio of ‘useful’ outputs to energy inputs for a system; using less energy to provide the same level of energy service. An example would be insulating a building to use less heating
and cooling energy to achieve the same temperature. Energy conservation is the practice of decreasing the quantity of energy used. It may be achieved through efficient energy use or by reduced consumption of energy
services. Energy conservation may result in increase of financial capital, environmental value, national security, personal security, and human comfort and reduced costs for consumers and businesses. With an energy crisis