Building a solar-powered drip irrigation system provides many benefits and is quite easy to design and install. We just installed a drip irrigation system this year into our garden and it has cut our watering time by 70%.
Our irrigation system uses quite a bit less water, as we water our plants directly and the water has time to absorb into the ground, providing a deeper watering of the root systems.
We placed our system on solar power as we live 100% off grid. Our garden is quite far from our main solar power system, so we built a small solar setup just for the drip irrigation system.
This is something anyone can do and is quite affordable, will save you time and money, and can be set up on a timer, allowing for a fully autonomous watering system.
In this article, I will explain how to set up a drip irrigation system for your garden, and then I will go over how to run your drip irrigation system completely off of solar power.
It's finally here! Check out the companion video I just created for this article:
Part One: Building a Successful Drip Irrigation System
Drip irrigation systems can be used for any of your watering needs! The only difference between irrigating small hobby gardens to farming operations is the scale of your system. Larger watering operations will call for larger drip tubes, larger pumps, and more drippers. But the concept is the same and can always be expanded upon.
You can accommodate drip systems to all sorts of landscapes, soil types and can go around obstacles, so the sky is the limit on how you want to design your drip irrigation system!
Step One: Design Your Drip Irrigation System Layout
The key is good design from the beginning. Ideally, you will want to build your system before you plant. You can always add in a drip irrigation system, but it will be quite difficult to maneuver around large crops.
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.
Considerations for designing your drip irrigation system:
- Location of your water source 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)
The easiest route is designing a rectangular garden with straight rows, which suits most gardening situations.
Step Two: Set up Your Water Source
This step is interchangeable with step one as water is the ultimate dictator of how and where your garden will be.
We have found the easiest method for us is using a water tank system. We fill our water tanks (two 330 gallon food grade IBC tanks) and run the drip irrigation from those. Since we are hauling in water, it makes sense for us to have a standalone tank that we can fill which is separate from our residential water use.
If you are running a well on your property, I also suggest using a water tank system. If you are on municipal water, you can run the hose straight into the pump. If you are using a natural source of water, you can use a submersible pump straight into the drip system, but I still would recommend a tank system in this situation.
We found our IBC tanks on Facebook Marketplace for about $150.
Step Three: Make Important Drip Irrigation Calculations
Calculating anything sounds intimidating, but this step is actually quite easy. It is highly important to know how much water your system will be using to properly size your water pump. You will also want to figure out how many drippers you need and how much footage of drip tubing you need for irrigation.
First Calculation: Calculate the GPH Of Drippers By Soil Type
- Clay – .5 GPH drippers
- Regular soil – 1 GPH drippers
- Sandy soil – 2 GPH drippers
We decided to go with adjustable drippers which has been quite a help in the garden! As our plants get larger, they require more water, so we can adjust accordingly. Some plants like more water, some plants like less. I also like that we can fully turn off the dripper in case a plant doesn’t make it or planting plans change. The only downside is that they are a bit fiddly and requires observation to see how much water your plant needs and the ground absorbs.
Second Calculation: Add up how many drippers you will be using
This can fluctuate quite a bit! I suggest having more than fewer drippers on hand. The main issue is that you do not want to exceed your GPH flow of your pump or else you may end up not having enough water to push through to the end of the system.
Cody had a genius idea and installed valves at each line so we can control watering zones. So far it has been a huge help as our pump cannot quite keep up with our water usage.
You also can use one dripper to water an area as opposed to just one plant, which works well for carrots and radishes.
Third Calculation: Add up your total GPH Usage
This one is easy:
X amount of drippers * GPH of drippers = Total GPH usage
For example, if you have 75 drippers, multiply 75 by the GPH of the dripper (1 GPH) and your total GPH flow rate is 75 GPH.
Fourth Calculation: Determine Your Drip line tubing diameter
Now that you know your GPH usage, you can select the correct mainline tubing.
The most commonly found sizing for mainline tubing is 1/2 inch which should take care of most household gardening setups. We actually went with the 3/4 inch size for our mainline with the 1/2 for our drip lines. The results are working quite well.
We use 1/4 inch line (which is quite small) to individual plants and containers.
Max Run Length
Max GPH Flow
Make sure not to surpass the maximum GPH of the tubing which will be listed on the manufacturer’s instructions and do not overextend the tubing past its maximum run length.
Step Four: Purchase Drip irrigation components
I can tell you that generic drip irrigation systems being sold on Amazon are complete CRAP. I strongly suggest staying away from those systems as the components are flimsy, do not last, and don’t even fit together!
Our drip irrigation system is 100% built with components from Drip Depot. I am so happy with their products and service that I will exclusively stick with this brand for when we expand our system.
What I love about Drip Depot is that everything fits! I don’t have to worry about ill-fitting parts and pieces from different manufacturers. They offer free shipping that arrived to us within a few days.
Their selection of parts, pieces, and kits is massive and everything syncs together so nicely if you ever want to expand your system. They pretty much have every doodad you could possibly ever want to build anything that drips!
We built our drip irrigation system for our 1500 sq ft garden for under $300 and have parts and pieces to spare (not including the water pump).
I suggest heading over to their website and checking out what they have to offer!
Drip Depot has some great kits that has everything you need to get your system up and running. Here is one you might want to consider if you have raised beds:
Premium Drip Irrigation Kit for Raised Bed Gardening
Our garden was already planted when we built the system, so we needed to custom build. We went with building out our own system inspired by the kits, but instead of using drip tubing with pre-punched holes, we opted for mainline tubing and punched in our own holes, which is quite easy with a puncher.
Do not switch parts between imperial and metric system! The calculations are slightly off between the measurements and you will end up with leaks all over the place. Stick with one or the other. Drip Depot only offers imperial measuring system.
Here is the list of items you will need for building your own custom drip irrigation system:
Mainline and Drip Line 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.
Mainline tubing does not come pre-punched with holes. We purchased 1/2 inch mainline tubing and punched holes in it for use as the drip line, as we had already planted and needed custom holes.
Drip irrigation emitters – these are the drippers that you install 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 of drippers, the most common are standard drippers, bubblers, sprinklers, and sprayers, although we are really enjoying the adjustable drippers. 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 between plants is typical.
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.
We used barbed fittings for our system and it has worked out quite well.
Inline tube shutoff valves - these are great for creating gardening zones and work well if you do not have quite the water power to water your entire garden at one time.
Hole puncher – this is a must-have tool if your tubing does not have holes. This punches the holes into the tubing where you insert your dripper. I like this cutter/puncher combo tool. It slices through the tubing very easily and makes perfect dripper holes.
Tubing End Caps - These special end caps are a cinch to install and are leakproof. You can also get clamps and fold over the end of the tubing, but I think these work much better and they are cheap.
Worm Gear Clamps - Anywhere that you install a connector or fitting will require a clamp to keep tubing secure.
Goof plugs – to plug up holes in your tubing that are no longer needed or placed by mistake.
Barbed Tubing Couplings – these are for attaching 1/4 inch drip line to 1/2 inch drip line for containers and extending the reach of your drippers. Very helpful to have!
Tubing stakes – keeps the tube from rolling around – which it will – if not fixated onto the ground.
Irrigation Backflow Preventer – 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. I recommend not skipping this component!
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 and 35, then you may not need one, depending on how large your system is. We have one and it really helps regulate the pressure going into the system and we get better water flow from the drippers.
Inline Water Filter – Your water might already be filtered , but the tiny emitters get clogged easily. Take the extra precaution and purchase an additional filter for your drip system. It may feel redundant but is worth the peace of mind knowing that your emitters will not get clogged up as easily.
Hose connect adapter – this connects your garden hose to the mainline of the irrigation system.
Water Transfer Pump – Last, but not least, is the water pump. I suggest a water transfer pump. I explain how to properly size your water pump in the next section.
Step Five: Install The Drip Irrigation System In the Correct Order
Now for the fun part! It really does not take much to install the system, but things need to be installed in proper order and some things can be a bit finicky. Patience, not rushing the process, and doing things in the proper order will save you time and frustration.
1. Start installation at the water source
If you are on municipal water, you will need to install a backflow preventer to keep water from backwashing into your system. Backwashed water can introduce bacteria into your residential water. If you are using a tank only for your drip irrigation system, then you do not need a backflow preventer. However, I do recommend a backflow preventer for all drip systems as it prevents dirty garden soil from going back into the system.
Install components in this order:
- Water tank to water hose
- Water hose to pump
- Pump to backflow preventer
- Backflow preventer to pressure regulator
- Pressure regulator to inline hose filter
- Inline hose filter to tubing adapter
- Tubing adapter to mainline tubing
2. Position, Cut and Fit All of your drip lines
Roll out your mainline and cut it at the end. Roll out your drip lines and cut at the end. Do not add end plugs at this point. Get all of your cut drip lines fitted together with your fittings onto the mainline. You can optionally install shutoff valves at this point. We like the shutoff valves and recommend them, but you don’t have to put them in.
3. Flush your system
Before you install all of your drippers, flush your entire system. This will keep your drippers from plugging up if you get some dirt into the line while installing, which you most likely will!
4. Install your drip emitters
Use your hole puncher and punch holes where you will be installing drippers. Now, it is not easy to push these emitters into the little holes. Rather, it's quite a pain in the ass! It goes better if your line is warmed up. Your fingers and hands will be sore and tired from fitting drippers and 1/4 inch line onto your drip line. If you have arthritis or hand issues, you may want some help with this step.
Once your drippers are installed, stake the line to the ground. And you are done!
Part Two: Building a Solar Powered Drip Irrigation System
Now that we have built our drip irrigation system, it's time to power it up with solar power! This is a great option for those that have a garden far away from their main power source, or for those who are gardening off grid.
This is actually a very easy setup. There is no reason to complicate your solar power build, as this works so simply and can be adjusted to scale. Pumps don't take a whole lot of energy and it only needs to run for about 20-30 minutes, depending on how much water your plants need. We find that a 20 minute run gives our plants enough water, and we live in Arizona!
How does a solar powered water pump work?
A solar powered water pump works by attaching a solar panel to a charge controller and then to a battery, it is really as simple as that. The components do not cost much, your main cost will be the battery.
The pump will run indefinitely while power is being delivered to it, which is why it’s important to install a timer in between the pump and the battery, or choose a pump that auto shuts off at a certain PSI.
Are solar powered pump kits worth it?
There are pumps that are sold as "solar powered pumps" and they absolutely SUCK. The pumps themselves are complete garbage, and the kits don't even come with a battery. There really isn't any need to waste your time or dollars on one of those crappy solar powered water fountain pumps as they will not deliver on what you need to run a drip irrigation system. A custom build is simple, affordable, and more reliable.
How to Build a DIY Solar Powered Irrigation Pump
The key to success is to prepare all of your calculations and components before you assemble and power up your system. Solar power systems are not all that complicated but you need to make sure all of your components will be compatible or else you could damage your system.
Let’s get started!
Parts You Will Need
50 Watt Solar Panel Kit for under $100
Let's make it easy! Get this kit and you have all the solar components you need, minus the battery. It comes with a 50 watt panel, charge controller, and cables. Easy and DONE.
You can piece these parts together from other sellers but I don't think you will get a better price.
If you don't get this kit, then you will need to appropriately size your charge controller. No, you cannot leave out the controller!
To figure out what size controller you need, take the output watts of the solar panel and divide it by the volts of your battery. This will figure out the amps calculation for controller sizing.
100 watts / 12v = 8.33 amps
Battery – stores power in a bank so you can run your system even when the sun is not out. Here is a 35 aH battery for under $100.
Battery powered timer - This step is optional, but creates a fully autonomous system and is great for when you are going to be away for a bit.
Step 1: Correctly Sizing Your Water Pump
1We need to figure out how much water we are going to need for our drip irrigation system (calculated in the first section of this article) and then purchase the correct size water pump.Too little water flow and we will not have enough water to run the system. Too much water flow and we could overload the system, causing damage.
In our example, we need 75 gallons per hour flowing through our system. Most pumps measure in gallons per minute, so we divide 75 gallons by 60 minutes to get 1.25 gallons per minute.
Try to match up the flow rate of your pump as closely as you can to the GPH of the drip irrigation system. You may not find the exact pump for your calculation, but either err on the side of less GPM as opposed to higher GPM. You can also add a few more (or less) drippers to match up better to the flow of your pump.
You also must consider the PSI that your system needs. Drip irrigation systems need 15-30 PSI. If you cannot find a pump within your PSI requirements, get the PSI regulator part.
If your pump is having to move water to a higher ground, you need to consider the elevation change. Suction lift needs to be calculated in for loss of pressure.
You will also need to consider friction loss for larger drip irrigation systems. Most manufacturers will have a friction loss chart available. We haven't had any issues with friction loss, but our size irrigation system can be compared to a large hobby garden. For farming operations, you must consider friction loss!
For more information about selecting the proper pump, I suggest reading this very thorough, yet easy to follow, pump selection and calculation guide by Drip Depot: https://help.dripdepot.com/support/solutions/articles/11000061728-water-pump-buying-guide.
This Seaflo pump moves 3 gallons per minute (90 GPH) and would work for smaller drip irrigation installations.
Step 2: Choosing the correct size solar panel
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.
Volts times Amps = Power in Watts
For our example, we are using a 12 Volt DC 7.5 amp water pump. So our calculation is:
12 Volts x 7.5 Amps = 90 Watts per hour
For our pump, a 100-watt solar panel will provide enough electricity plus a little extra to keep the battery charged while the pump is running.
However, since our pump will not be running 24/7, we can downgrade the size of the solar panel and rely on the battery backup to run the pump for an hour or two, and then while the pump is off, the solar panel will charge the battery. In this case, we can choose the commonly sized 50-watt solar panel.
Note that our pump is a DC pump, so we do not need a power inverter to power the pump as the power supplied by solar panels is also DC.
Step 3: Choosing the correct size battery
We want to make sure that we select a battery with enough capacity to run the pump if the solar panel is operating at zero capacity.
Let’s stick with the 100 watt solar panel for our example.
100 watts is the amount that the solar panel will produce per hour.
The average amount of power a solar panel can collect per day is typically 500 watts based on being in full sun for 5 hours.
While the battery is charging, there are some power losses of about 15%. So our 500 watts will probably be more along the lines of 425 watts.
Battery capacity is expressed in Amp hours (Ah).
We know that we need a 12 volt battery for our pump.
We multiply our battery Amp hours (Ah) by the voltage:
Ah * Volts = Watts by the hour
So if we have a 35Ah 12V battery we simply multiply the two 35 * 12 = 420 Wh which will store most of the output of our solar panel.
Now, our pump will only be running for 2 hours out of the day. We need 90 watts per hour, so our system will only require 180 watts. Therefore, a 35Ah battery will give us a bit more than 2 days runtime without having to be charged.
Step 4: Connecting the solar power components in correct order
Before proceeding, make sure your solar panel is not in the sun. You can place a piece of cardboard over the panel to ensure there is no electricity running through it.
The first step is to hookup the charge controller to the battery with stranded copper wire. Make sure not to cross-connect the + and -.
The second step is to connect your timer to the battery. I suggest using the negative cable as it’s not hot. Splice in the timer on the negative cable. A battery-powered timer is ideal if you don’t want to mess with wiring power to the timer.
The third step is to connect the pump to the timer and the battery.
The fourth and final step is to hook up the solar panel to the charge controller with the appropriate solar panel connector cables, which are usually included with the solar panel.
Make sure not to cross-connect the + and – MC4 connectors as this will damage your system.
Once all the components are connected, you can uncover the solar panel and the battery will start charging. The charge controller will inform you when it is full and regulate the battery to keep it in optimal charge.
I suggest giving the battery one good day of charging before running the pump.
I also suggest placing the battery and controller in a tote or housing to keep safe from the elements.
And that's it! You now have a solar powered drip irrigation system, just like that!
You can read on for some more information about drip irrigation systems if you like, but this concludes the tutorial of how to build one. Have that wonderful day and let me know how your build went!
Is Drip Irrigation Even Worth It?
You may be wondering why using a drip irrigation system is right for your garden. After all, if your sprinkler system is working decently enough, why go through the hassle and expense of taking on a more complex garden watering system?
Before you decide that installing a drip irrigation system is worth it or not, take a look at the advantages and disadvantages first.
Advantages of drip irrigation
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.
A drip irrigation system makes desert farming possible
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.
You can use a drip irrigation system for just about any farming method, including vertical farming. You can read about my vertical farming systems guide here.
Although there are many numerous advantages to drip systems, there are cons as well to consider.
Disadvantages of drip irrigation
As I have come to find out through all of my research, there are always downsides to any system, including systems that seem like a perfect solution. Drip irrigation is not perfect and does need to be evaluated for each unique gardening and farming situation.
There is a higher initial cost for starting a drip irrigation system. You can save money in the long run from saved resources, but be prepared to shell out a good buck or two upfront. In all reality, its really not all that expensive to set up a drip system for a hobby garden.
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, small farms, growing in arid climates and on difficult terrains, a solar power drip irrigation makes plenty of sense.
Drip irrigation vs sprinkler irrigation
Still not sure if drip irrigation is worth it? I have made this handy comparison table so you can compare drip to sprinkler:
150 GPH (per 1GPH drippers @ 150 plants)
1,020 GPH (per 60 PPSI @ 5/8" Hose)
$100-$250 small to mid size system
$25-50 small to mid size sprinkler
soil, sand, arid
Overall, my consensus is that drip irrigation is the better watering choice for home gardens, hobby farms, and arid climates. You can utilize more spaces and soil types and will save money in the long run. Just be sure to maintain your system to get the maximum life out of the components.
What are the benefits of solar irrigation?
The main reason I love the concept of solar irrigation is the fact that you can build an autonomous energy saving off grid gardening watering system anywhere and in any climate.
When you add a solar power system to an irrigation system, you can virtually run that watering system anywhere, as long as you have a water source. This could be a spring, year-round creek, well, or pond. Solar power components used to be expensive but have come down considerably in price and have become more effective.
Solar powered drip irrigation systems are an excellent choice for off grid gardens, remote farms, and any garden that may be too far from a convenient- power source.
Ultimately, we are very happy with our drip irrigation system. And its even better operating on solar power! It saves us time, money and hassle. And we garden in the desert, so we are saving on water too.
If we were in an area that received lots of rain, we probably wouldn't have bothered with a drip system. If we had a small garden, we would probably just hand water.
A drip system works great for us in our situation and you may find the same results as well.