Generators are devices that convert motive power into electrical power for use in an external circuit. Most generators are tow-able, and are powered by Diesel Fuel. Sizes and applications range from a small unit used for a camping trip, to exponentially large units that provide power in lapse of the established power grid. Generators provide access to electricity when it would be otherwise unattainable due to natural disasters, electrical line repair, or on site job applications where direct current power is needed to operate different tools and machines but no access to the power grid is available. Power generation units usually run on a full tank of fuel for 14 to 28 hours on average.