Solar Powered Sump Pump

Hi David - there are of course many variables that have to be considered in your application. You mentioned 25 gallons per hour but how many hours per day does the pump run?  A good place to start is with an inexpensive power meter that you can get from a number of places (you can get one from AltEnergyStore). It plugs in between the pump and the outlet and you can get some long term data (several days or a week for example).  From that you will know enough to size the system you need.  However, since your sump pump presumably has to run when the water level rises, you can't afford to have the system run out of juice (that's the technical term) when you really need it.  Therefore I don't recommend solar unless you have a way to automatically switch the system over to conventional power in case the solar system runs low, as the results (flooding) could be catastrophic to your home.

Tom Hardy, PE
HVTA, Inc.