Solar No Sun – How to Keep Water Flowing Without Sunshine
One of the most common questions about solar water pumping is, what happens with “solar no sun” situations? Whether it’s at night, during cloudy days, or in long periods of rain, the answer is straightforward: pair your solar pump with a properly sized water storage tank.
Why Storage Solves the “Solar No Sun” Challenge
A solar water pump works hardest during daylight, filling your tank with enough water to cover several days of use. This way, when there is solar no sun, you still have stored water ready for household supply, irrigation, or livestock. Think of the tank as a “water battery” that stores energy in the form of usable water.
Recommended Tank Size
To ensure reliability, size your tank for at least 3 days of demand:
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Household: If you use 800 gallons per day, aim for 2,400 gallons minimum.
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Farms & irrigation: Base the calculation on your peak daily water needs.
Once sunlight returns, your pump quickly refills the tank, restoring reserves.
Water Storage vs. Batteries
Many people think about adding batteries for solar no sun conditions, but water storage is simpler and more cost-effective:
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No expensive battery banks
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No battery replacement cycle
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Directly provides usable water without conversion losses
This makes water storage the most reliable backup for solar pumping systems.
Placement & Gravity Flow
To maximize flow during solar no sun conditions, position the tank above your usage points. Remember: every 33 feet (10 meters) of height provides ~14.5 psi of water pressure. Consider irrigation distance, pipe size, and method (drip vs sprinkler) when calculating tank height.
Final Thoughts
With the right storage design, “solar no sun” no longer means “no water.” By pumping during the day and storing extra, you’ll always have an eco-friendly, dependable water supply—rain or shine. Let's check out our solar pump collection at Products – OmniHydro
