When the power goes out in a residential neighborhood or commercial business and will not be restored for awhile, a common substitute for your energy needs is a generator. A generator acts independent of the power grid as it derives it's energy from a gas powered engine. Since a generator is small and mobile it can be easily transported to job sites, fairs or camping trips where power from the grid is not readily available.
Portable generators can power things such as most standard 120/240v electric power tools, lighting equipment, fans, blowers. Some of them have automatic idle control as fuel conservation and noise control features. They are typically small enough to be carried by one or two adults.