Answer:
Energy sources do not have 100% efficiency because the processes of energy conversion to usable forms involves energy losses.
Some have lower efficiencies due to; energy losses in form of heat during conversion, poor technology applied during conversion of energy and lack of desire equipment to use in the energy conversion system.
Step-by-step explanation:
The desired form of energy for use is derived from conversion of energy from the source using an energy converter into another form which is usable. The efficiency of the energy converter is calculated as;
ะป = output energy/input energy
The efficiency of energy is limited to the cost of equipment required for conversion from energy source by the energy converter to a form which is usable. Additionally, because energy sources are scarce, the technology to use in energy conversion is a factor affecting energy efficiency in that high efficiency will require advanced technology with better equipment leading higher costs of that energy form. when heat losses are involved during energy conversion, efficiency lowers, thus its better if such losses are used as energy input in another system.