C) Wind energy is less efficient (even when running at their optimum wind speed) because There's friction between all the moving parts, the generator or alternator aren't 100% efficient, and the energy is lost at the rotor blade friction and drag, gearbox losses, generator and converter losses, reduce the power delivered by a wind turbine. The basic relation that the turbine power is proportional to the power of velocity remains.
D) Solar panels are made of solar cells; a cell is a small disk of semiconductors. They’re attached by wires to circuit. As light strikes the semiconductors, the light is converted into electricity that flows through the circuit. As soon as the light is removed, the solar cells stop producing power.
Solar cells are placed next to one another on top of a back sheet and are covered by glass to make up a solar panel. The reason why solar cells are less efficient is because only 30% of sun energy produced useful energy of electricity and 70% of energy was loss By an estimate of 40% of the solar energy gets converted to heat. 20% of the photons pass through the solar cell and 10% of energy is lost from local recombination of newly created holes and electrons.
Another reason why solar energy is less efficient is because