How to Build a Solar Powered Drip Irrigation System for Your Garden

There are multiple systems that must be in place in order for our gardens and farms to be productive and worth all the labor and money we pour into them.

The more efficient we can make any of these systems, the more time and money we will save in the long run.

A solar power drip irrigation system combines two resource-saving systems into one: power and water.

Both systems take a little extra work and money in the beginning, but the rewards that you will reap in the long run make these efforts worth it.

In this guide, I will teach you how to set up drip irrigation and then tie it in with solar power.

Let’s go!

Phase 1: Setting Up Your Drip Irrigation System

Why use a drip irrigation system?

Before we delve into the design and construction of our watering system, you may be wondering why using a drip irrigation system is right for your garden in the first place. After all, the sprinkler system works decently enough.

There are loads of advantages for installing a drip irrigation system over a sprinkler or hand watering system.

  • Water efficiency is superior in comparison to a sprinkler system. A drip irrigation system works by depositing the water directly onto the soil and into the plant. Hardly any of the water runs off as the system directly soaks the soil. 
  • There is also very little evaporation, leaving the drip system to produce the least amount of water waste.
  • Nutrient loss is minimized as fertilizers do not run off the ground as opposed to hand or sprinkler methods. Therefore, less fertilizer needs to be used, by as much as 30%, which saves money and lessens groundwater contamination.

  • A drip system can be installed on any type of terrain, including hills and sandy lands, making more areas open to cultivation.
  • Arid, windy, and sandy environments that used to be barriers to cultivation can be utilized with a drip system.
  • Yields can be increased drastically. A study done by the Directorate of Water Management Research found fruit yields to be 12% higher while using over 30% less water.

  • Weeds that grow around the crop are greatly reduced as the water and nutrients only go to the intended plant.
  • Operational costs are lower as the pressure needed is reduced; costs are driven even lower when combined with a solar power pump system.
  • Unusually shaped or hard to reach areas can be used for planting which is traditionally difficult to water. This could be by a twisting walkway or a narrow strip of yard along a driveway.

Although there are many numerous advantages to drip systems, there are cons as well to consider.

Disadvantages to a drip irrigation system

There is a higher initial cost for starting a drip system.

  • Drip systems are great for small scale farming, but on a larger scale, the cost to replace damaged and worn equipment from UV light and movement will require a recurring investment.
  • The little holes in the hoses can get clogged up, causing them to dysfunction. Filtered water is a must and regular flushing maintenance is required to keep the system running.

  • Although water distribution is much easier, figuring out how much water to use for each growing phase will require some observation and research.
  • The salinity of the soil can increase over time as the saturated wet soil evaporates and leaves the salt on top.

In most backyard gardens and small farms, a solar power drip irrigation makes plenty of sense.

How To Setup And Install Drip Irrigation System

Step one: Plan out your drip irrigation system thoroughly.

Propper planning prevents poor performance! You don’t want to haphazardly construct your system only to find points of failure down the road.

Making a sketch of your garden will help you engineer the right layout and could help you see problem points that you wouldn’t have otherwise noticed. Take note of dimensions and unmovable structures and objects.

Some things to take note of when designing your system:

  • Where your water source is located and if there are any obstacles along the way
  • The distances you will need to run your irrigation tubing
  • Designing your system without crossing over walkways or burying the pipe under walkways
  • Utilizing spaces along paths to grow vegetables and herbs (a permaculture philosophy)
  • Laying out your system to use the least amount of pipe and tube for efficiency
  • different gardening zones may require different amounts of water (a more complex form of drip irrigation)

Drip Irrigation Design Calculations

Make sure you buy the right drippers for your soil type. Different types of soil require different rates of drip that is calculated in Gallons per Hour (GPH).

  • Soil requires 1 GPH drippers
  • Sandy soil requires 2 GPH drippers
  • Clay requires .5 GPH drippers.

Once you have decided your soil type, you need to calculate your total Gallons per Hour usage.

Add up all the drippers your system will use. let’s say you are using 80 2 GPH drippers, that makes your total usage 160 Gallons per Hour.

Based on that calculation, you can decide on the diameter of your mainline tubing.

A .5 inch mainline can handle between 150 – 220 GPH which will accommodate our 160 GPH usage.

The manufacturer should list the GPH on the packaging.

There are also maximum GPH depending on the diameter which will be listed with the manufacturer’s instructions.

You also don’t want to overextend your irrigation tubing. A .5 inch irrigation tube should not be run any longer than 200 feet.

Step two: Gather supplies

Absolute basics for a simple drip system:

Drip tubing – this is a special tubing specifically designed for drip irrigation systems. It is a thin polyethylene tube that is much thinner than a standard hose. Drip tubing is meant for above ground use, do not bury the tubing underground, it will ruin it.

Drip irrigation emitters – these are the dripper devices that are installed along the tubing. Some tubes have them pre-installed, otherwise, these can be bought separately and installed onto the tubing. For manual install, you will need a hole puncher.

 

There are different varieties, the most common are drippers, bubblers, sprinklers, and sprayers. The spacing between the emitters will depend on the plant type you are growing and how your tubing is laid out. Anywhere from 6 to 24 inches is common.

Irrigation backflow preventers – an essential piece to the setup, the backflow preventer keeps dirty garden water from flowing backward in the tubing. Backflow can contain contaminants that spread soil born disease. Do not skimp on this piece.

Pressure regulator – this reduces the pressure to a consistent PSI level to not overload the system. If your water pressure is above 40 PSI then you will need a regulator. If your pressure is between 25 to 35, then you do not need one.

Filter – Your water might already be filtered, but the tiny emitters can get clogged easily. So purchase an additional filter for your drip system. It may feel redundant but is worth the additional security knowing that your emitters will not get clogged up. 

Hose connect adapter – this connects your water source to the mainline of the irrigation system.

End cap or hose end clamps – the end piece to cap off or clamp the end of the tubing and mainline.

Tubing stakes – keeps the tube from rolling around, which it will, if not fixated onto the ground.

Additional materials for more complex system:

Timer – a timer will allow for a completely autonomous system. This component will be covered in the solar power phase of the project.

electric timer for pumps

Fittings – includes couplings, elbow fittings, barbed tees, barbed connectors, tee fittings. All these components add options for a more complex system, such as running multiple drip tubing lines from the mainline, connecting .25 inch line to .5 inch main line, creating branch lines, etc.

You may also want to pick up some goof plugs to plug up holes in your tubing that are no longer needed or placed by mistake.

Once you have all your materials purchased and your design engineered, its time to roll out the system!

Special note on drip irrigation components

many components for drip irrigation systems are measured in the metric system. There are labeled conversions that are not entirely correct which can cause your system to fail.

It is recommended that instead of trying to convert from metric to imperial (15mm and 16mm are both labeled as ½ inch!) stick to the metric system.

Your fittings need to be precise. Even a millimeter off can blow your entire system over time. Plan accordingly.

Step Three: Installation

The first step of starting your installation is at the water source. This could be your water valve if you are plumbed in or could be the adapter fitting directly onto your pump for off grid systems.

Install components in this order: Valve or pump, backflow preventer, pressure regulator, filter, tubing adapter, mainline tubing.

The second step is to lay out all your tubing. Start by connecting your .5 inch mainline tubing and then position your tubing that branches out from the mainline and adjust as necessary. If the tubing is too stiff, let it sit in the sun to warm up, which makes it more pliable.

Use additional fittings, such as elbows for bends, as necessary for your setup.

Once you have everything laid out to plan, cut the hoses at the end but do not clamp off just yet.

The third step is installing your emitters. You may have purchased tubing with emitters already installed, if so, then skip this step. To manually install emitters, simply punch a hole into the tubing with a hole puncher, then press the emitter into the hole.

Once you are done with the emitter installation, stake to the ground.

The final step is to flush the system with water to remove any debris, then cap or clamp the ends.

Run your system for about an hour and check to see if any adjustments need to be made. Now enjoy the fruits of your labor!

 

Phase Two: Adding Solar Power To Your Drip Irrigation System

The component that requires solar power for your drip irrigation system is the pump. Adding solar power to your water pump is an ideal solution if your primary power source is too far away or inconvenient to run the pump.

There are many ways to get solar power to a pump; the goal is to make the system as simple and independent as possible. I will be focusing on the simplest, most direct use of a solar panel to get the results we want.

Essential Components for a Solar Powered Pump

Solar panel – collects the energy to run the pump.

Solar controller/regulator – Keeps the battery powered and charged.

Battery – keeps the system running if there is no sunlight for a small period of time.

Cables – to connect components.

Step one: Figure out how much power the pump requires.

We need to figure out how many watts are needed to appropriately size the solar panel. If wattage is unknown, you can calculate it with a simple equation by using the voltage output and amps.

Power in Watts = Volts times Amps

For our example, we are using the Shurflo 12VDC 7.5 amp water pump. So our calculation is 12 x 7.5 = 90 watts. Note that this is a rough calculation and many other factors may come into play but this should do in a pinch.

For our pump, a 100-watt panel will provide enough electricity plus a little extra to keep the battery charged while the pump is running.

Step two: Connect the charge controller to the battery.

When bought in a bundled kit, all of your solar power components will be compatible and include mounting materials and the wiring necessary. 

I have written a Solar Power 101 guide that goes over all the components for a solar power system. 

Charge controller for solar setup

Although this very basic solar power design won’t require all the components needed for a home installation, my guide explains all the parts involved in the system. 

Step three: Set up the battery.

You will want to get a battery that is matched to the output of your solar panel. For our setup, we are using a 100 watt solar panel.

The figure of 100 watts is how much the panel can output while in full direct sunlight per hour, known as a watt hour (Wh). Therefore, our solar panel creates 100 watts per hour, times that by 4 hours of direct sunlight which equals to 400 Wh output per day.

When the battery is being charged, there will be some losses. We will calculate in a 15% loss of energy when charging the battery, therefore our 400Wh is now 340 Wh.

Battery capacity is expressed in Amp hours (Ah). We know that we need a 12 volt battery for our pump. So if we have a 33Ah 12V battery we simply multiply the two 33 * 12 = 396 Wh which will store the output of power from our solar panel.

Step four: Wire in the timer from the battery to the pump.

Make sure that you get a 12-volt timer to match the 12-volt battery.

Step five: Connect the solar panel to the controller.

Make sure all your connections are sound and complete before connecting the solar panel.

I hope that my solar powered drip irrigation setup guide will help you develop an irrigation system that you can use for your garden.

If you have any questions or comments please leave them below. 

Also, feel free to share my article with your friends on social media!

Have a good one!

Hello, I am Regina! I am the creator and brain-child behind Maximum Off Grid. 

My goal is to educate and inform people interested in becoming independent from the system. 

I also provide valuable reviews on products and service that I research thoroughly and make quality  recommendations.

I hope you are enjoying my website!

Regina C. 
Creator of Maximum Off Grid

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