
In an , a of a voltage or current waveform is a whose frequency is an integer multiple of the . Harmonic frequencies are produced by the action of non-linear loads such as , , or saturated . They are a frequent cause of problems and can result in increased equipment and conductor heating, misfiring in , and torque pulsations in mo.

Solar power, also known as solar electricity, is the conversion of energy from into , either directly using (PV) or indirectly using . use the to convert light into an . Concentrated solar power systems use or mirrors and systems to focus a large area of sunlight to a hot spot, often.