Solar Powered Water Pump Power Options Linear Current Booster or Batteries or Both

If you are powering a direct current solar water pump, be it a well pump, a booster pump, a recirculating pump or any other kind of DC pump, there are two basic ways to power your pump: using a solar panel or panels and a linear current booster; or using a solar panel or panels with a battery bank.

Linear Current Booster to Pump During Daylight Hours Only

If you only need to pump water during daylight hours for things like filling a tank or irrigating the garden or orchard, using a linear current booster is the least cost way to do this.  A LCB boosts the current flow from a solar panel by sacrificing voltage to the pump.  The advantage of doing this is that the pump can start earlier in the morning and run later in the afternoon or can operate from a smaller solar panel than a direct connection between the solar panel and the pump.

The other advantage of using a LCB is that you can pump 30 to 100 percent more water and can often pump water on cloudy days when a panel direct connection would not provide enough energy to run the pump.

The disadvantage of using a LCB is that the pump will run slower during these early and late periods than it will run during peak sun hours.  And, you will not have any water pumping happening at night.

Charging Batteries to Pump Around the Clock

If you need to pump water any time of the day or night, then a solar panel with a battery bank is the best way to go.  This is the higher cost option.  The solar panels connect to a charge controller which connects to and charges the battery.  The pump is powered by the battery.

The issues that need to be determined to size a system for pumping from a battery include:

  • Your geographic location to determine sun hours per day available for charging with the system sized for the least sunny time of the year in your location.

  • The size of your pump, capacity in gallons per minute, and if pumping from a well, the depth of the pump in your well.

  • Elevation rise or fall from the well head to where the water is being pumped.

  • The pressure needed if pumping into a pressurized system.

  • The best method to tell the pump when to pump and when to stop pumping, which could be a pressure switch or a float switch or a float valve and pressure switch.

  • The volume of water in gallons needed on a daily basis.

  • The number of days of "autonomy" which is the solar term for consecutive days of cloudy weather that you want the system to be 100 percent reliable without over discharging your battery bank.

  • The distance from the solar panel to the pump - with low voltage closer is better.

Combination Solar Pump Control

Some solar water pumping systems need to serve two purposes: water supply on demand 24 hours per day and occasional large volume water supply for things like lawn, garden or orchard irrigation, livestock watering, filling a large tank or maybe even a swimming pool.

We have developed a dual circuit control that can be switched to work either way - panel direct during daylight hours or pumping from batteries.  Separate solar panels are required for charging batteries.  The solar panels used for running the pump during daylight hours cannot be used at the same time to charge batteries.

Shade Free, Laid Back and Due South (due North if south of the Equator)

With either option, you need a location for your solar panel(s) that is shade free, especially during the peak time of the day from 9 AM until 3 PM.  Your solar panel needs to be mounted facing due south and tilted back to a degree equal to your latitude.

If you have a way to tilt your solar panel back an additional 15 degrees during the Summer and forward 15 degrees during the Winter, this will improve the performance.  Here in Tennessee we are at about 35 degrees North, so I adjust my panels to about 20 degrees in the Summer and 50 degrees in the Winter.

A top of pole solar panel mount is an easy way to make this possible.  The three major brands are all designed to easily adjust the tilt of the panels.

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Please contact us today for assistance with your applications and pricing or call us.