Are you looking for a way to irrigate an off-grid homestead garden or circulate water in a soilless growing system? If so, a solar powered water pump could be just the thing you need.
So, what is a solar powered water pump? A solar powered water pump is a water pump that uses electricity produced by PV (photovoltaic) solar panels. These pumps can use either AC (alternating current) or DC (direct current). A battery is optional, and it will store energy so that the pump can operate at night or on cloudy days.
Of course, there are lots of uses for solar powered water pumps, from water features to irrigation.
In this article, we’ll talk about solar powered water pumps, along with their advantages and disadvantages. We’ll also get into some of the uses for solar powered water pumps.
Let’s get started.
What Is A Solar Powered Water Pump?
The main parts of a solar powered water pump are:
- Solar Panel Array – this contains one or more PV solar panels. Each panel converts solar radiation (sunlight) into electricity. This electricity is the power source for the pump. Solar panels are less effective on cloudy days, and they do not work at night.
- Battery – this is an optional feature of a solar water pump system. A battery stores electricity from the solar panel array for use at night or on cloudy days. A battery adds extra cost to the system, but makes it feasible to pump water constantly.
- Controller – this is the “brain” of the system. It automatically adjusts power based on the amount of electricity the panels produce. It can also shut off the pump when the source water level is low.
- Electric Motor – this converts electricity from the battery or solar panel array into mechanical energy to run the water pump.
- Water Pump – this moves water from the water source (for example, a well, pond, or lake) through a pipe or hose to its destination (for example, a farm or garden).
As an alternative to a battery, a solar powered water pump can move the water into a raised storage tank when sun is shining. Then, gravity can act as the power source to move the water at night or on cloudy days.
Since batteries are expensive, this may offer a cost savings for a solar powered water pump system. Moving the water into a storage tank also offers the possibility of using sunlight to warm up the water for bathing.
Water Pump Current: AC or DC?
A solar powered water pump can use one of two types of current:
- AC (Alternating Current) – this type of pump works faster and lasts longer. However, according to Farm & Livestock Directory, an AC pump uses 4 to 8 times as much power as a DC pump. An AC pump also needs an alternator to convert DC from a solar panel into AC for the pump.
- DC (Direct Current) – this type of pump works slower, but is more energy efficient than an AC pump. This makes them good for fountains, landscaping, and irrigation in the home garden.
Water Pump Types: Surface or Submersible?
Water pumps come in two basic types:
- Surface Pump – this type of pump is placed on the ground, near the surface of the water source (such as a pond or lake). The pump uses power to pull water up into the pump and then pushes it to its destination through a pipe or hose.
- Submersible Pump – this type of pump is submerged in the water source. It is more efficient than a surface pump, since it doesn’t need to use energy to bring the water up to the pump. However, it is more expensive than a surface pump.
Advantages Of Solar Powered Water Pumps
Solar powered water pumps have many advantages over other types of water pumps, including:
- Clean – there is no chance of a fuel spill, since a solar water pump uses electricity from sunlight. This is important for applications related to drinking water or agriculture, since a small amount of fuel (such as gasoline) can contaminate many gallons of water.
- Labor Saving – once a solar water pump is installed, there is no need to transport fuel to power the motor. This saves on costs in the long term, and eliminates the possibility of fuel spills.
- Long Lasting – solar panels are durable and can last for decades. The pump itself will likely have a shorter lifespan and warranty.
- Mobile – a solar water pump can be mobile, so you can move it from one spot to another if a water source dries up.
- Off Grid – a solar powered water pump can operate off of the grid. This means that you don’t need to live close to power lines or pay to connect your home to the grid.
- Battery Option – you can add one or more batteries to a solar powered water pump system. Storing electricity when the sun is shining will allow you to use the pump at night or on cloudy days.
Disadvantages Of Solar Powered Water Pumps
Solar powered water pumps do have some disadvantages, including:
- Inconsistent Power – without a battery, you can only use the pump when the solar panel array is producing power. An AC system that uses more power can pump more water when it is working, but there will be more downtime, especially on cloudy days.
- Limited Locations – you can’t just set up a solar powered water pump anywhere you want. There needs to be a decent amount of sunlight hitting the solar panel array to produce enough power to run it. Installing the solar array far away from the pump means that you will need to run wires a long way to move the electricity from panels to pump.
- Setup Expenses – you will need to buy the system, including the solar panel array, controller, and the pump itself (plus batteries if you want them). You might also need to hire an electrician to help you install it, which adds additional setup costs.
Are Solar Powered Water Pumps Any Good?
A solar powered water pump can work well in climates with lots of sun and few clouds. With a battery to store power, they can be a reasonable alternative in other areas as well.
The performance of a solar powered water pump will depend on a few factors:
- Sunlight In Location – to get optimal sunlight, you will need to choose the best spot in your yard that is close to the water source. You might need to trim or remove trees to avoid shading the panels.
- Solar Array Capacity – the power that a solar water pump can use is limited by the amount of electricity that the solar array can produce. More panels will mean more power and more water pressure, but extra panels will take up more space.
- Height of Water Source and Tank – if the water source is low and the tank is at a high elevation, the pump will need to work harder and use more energy to lift the water and move it to where it needs to be.
- Pump Capacity – a larger pump can move more water, but it will need more power to maintain this increased flow.
- Battery Availability – a battery will give you more consistent performance, since you can store extra electricity when it is sunny and use the excess when it is cloudy.
Can A Solar Panel Power A Water Pump?
Depending on the size of the solar panel and the pump capacity, a single solar panel may be able to power a water pump.
According to Energy Sage, a home solar panel produces 250 to 400 watts. The number of solar panels you would need to power a pump system would depend on the wattage of the pump.
How Many Solar Panels Does It Take To Power A Water Pump?
The key equation is P = IV, or
- (Power) = (Current)x(Voltage)
Power (P) is given in watts, current (I) is given in amps, and voltage (V) is given in volts. Let’s try a calculation to see how it works.
For example, this Everbilt 1 horsepower Pump from Home Depot has an amperage of 11.8 amps (I = 11.8) and voltage of 230 volts (V = 230).
This tells us that the power is 11.8 x 230 = 2714 watts. If your solar panels are producing 250 watts each, then you would need 11 panels (2714 / 250 = 10.856, so round up to 11).
Of course, this pump can discharge 14 gallons per minute, and can lift water 152 feet. You may not need such a powerful pump.
Uses of Solar Powered Water Pumps
There are lots of uses for solar powered water pumps, including:
- Water Features – this includes landscaping features for your yard and garden, including water fountains, bird baths, and fish ponds.
- Garden Irrigation – with conventional gardening, you will need lots of water, and a solar powered water pump can move water to your crops during the day, when the sun is shining and they need it most. You can use the water from a pond, lake, or even a rain barrel as your source.
- Livestock – you can also use a solar water pump to provide water to your livestock (chickens, cows, pigs, horses, etc.)
- Well – you can draw water directly into the house or store it in a tank for later use.
- Pool – you can use a solar water pump system with a battery to keep the pool filter running day and night.
- Soilless Growing – any soilless growing system will need a water pump, whether hydroponics, aquaponics, or aeroponics.
- Fish Tank – an outdoor solar panel array can keep a fish tank pump running during the day. You would need a battery to store electricity to run the pump at night.
Now you know what a solar powered water pump is and how it works. You also know all about how these pumps can be used for many purposes in a garden or on a homestead.
You might also be interested in reading my article on using tap water in your garden.
I hope you found this article helpful. If so, please share it with someone who can use the information.