Sump pumps can be powered by electricity, gas, battery or water pressure, but are most commonly powered by AC electrical power. DC-powered pumps, or battery powered pumps are also common. In some cases, an AC-powered pump can be temporarily powered by a DC-powered sump system.
Sump pumps come in several different designs, including submersible sump pumps, water-powered sump pumps, pedestal pumps, and "floor sucker" sump pumps:
Submersible sump pumps: These are designed to be submerged in water, cooling themselves automatically. They are the longest lived and most powerful sump systems.
Water-powered sump pumps: These pumps depend on your water pressure to pump out water. Generally, 3-4 gallons of town water will need to be pumped out for each gallon of groundwater. They pump at very low capacities but do not need electrical power to run, making them popular as backup systems. However, when they run, they use water and may run up your water bill.
Pedestal sump pumps: These pumps cannot be submerged in water and stand on a tall pedestal in the sump pit. Without water to cool them down, they burn out easily. Their design also causes them to "wander" in the sump pit, increasing the likelihood of them jamming as they become wedged against the side of the sump pit.
"Floor Sucker" Pumps: These are pumps designed to pump out most of the water in an existing flood. They do not install in a sump pit, and they cannot turn themselves on. They are meant as a temporary solution to pump out a basement or crawl space that's already flooded before the other pump system is installed.
- Wikipedia's article on sump pump