I'm in the process of constructing a natural swimming pond. The key requirement is that half the surface area be plant life that filters the water. so, the desgn I have in mind is to run a pump from the pool water to the surrounding plants. the pump i am considering is a dc, 24 v, 3 amp, 72 watt 3gpm, shurflo 2088. now i am searching for the solar panel and am overwhelmed a little by the choices out there. the prices seem to vary a bit as well. any input appreciated.
Curt, a benefit of using solar for a water pumping application where a dc motor is used is that the system is voltage tolerant. A battery should not be required. It's possible to connect a solar panel directly to the pump motor. Of course, the pump will operate only when the panel is producing. If you size everything right, then you should get the flow required each day without resorting to a battery system. Go with the least expensive panel on a $/watt basis as long as it's UL listed. Astroenergy panels might be a good choice (see wholesalesolar.com). Note that you probably want a fairly large panel as these will provide sufficient voltage to take the pump to a high output. The open voltage on these large panels are generally at least 30 volts. A 250 watt panel at 30 volt open voltage might be a good match. Note that there is no danger of sending 250 watts through the pump motor as the voltage will not be high enough, but there is enough extra capacity to keep the motor at a high output even when the panel sees low solar flux. I don't know how well the pump can handle continuous duty at the voltage provided by such a panel, but providing long and/or thinner wires might be useful to drop the voltage to a safer level.
thanks for the help marcos and benji. yes, i planned to wire directly and avoid the cost of the battery, controller and inverter. from what i understand so far, the intent is to move the water slowly from the pool area to the plant area. so i don't need a continual, rapid flow. maybe 4-6 hours a day.