The run time of a fuel powered generator is usually expressed at a half load (50% capacity) or a quarter load (25% capacity) with a full tank. Take the following example. A generator has 8 hours run time at a half load. If it is a generator with 2000 watts running power then it can run for 8 hours when the load is kept at 1000 watts.

The run time of solar powered portable generators is measured in watts per hour or “WH”. Since there is no fuel tank, the run time depends on how big the connected load is.

Other important time figures are how many sun hours it needs to be fully charged.

Most solar power generators also include rechargeable batteries. In this case, the number of hours to reach full charge is also important to consider.