Power, Electric Power is a constant of modern lifestyle and became absolutely necessary at around the first half of the previous century. Though the continuum of the power generation scheme of modern cities, there is an outage from times to times.
Most of urban citizens can deal with an outage, but there are some critical situations where energy cannot be interrupted for more than a few seconds, in some cases - as Intensive Care Units of the Hospitals - the timespan is even more reduced.
Emergency Power Systems
According to Wikipedia, Emergency power …