Having a well is a great way to stay off-grid, and it is even better if you can run the well pump with solar. The good news is that any well pump can be powered by the sun.
How much solar power you need to run a well pump depends on the following factors:
- Pump Wattage
- Kind of Pump
- Type of Holding Tank
- Size of Well
- New or Existing Solar System
- Water Use
Read on to learn how these factors affect how much solar power you will need to run your well pump.
The amount of power, or wattage, that your well pump needs directly affects the amount of solar power you will require. As a general rule, a 100-watt pump needs five solar panels.
Most home well pumps use about 750 to 1500 watts when running.
To figure out how many solar panels you will need, take the wattage of your pump and divide it by the total wattage output of a single solar panel. So, if you have a 200-watt pump and one solar panel produces 20 watts of energy, you will need 10 panels.
Here is a summary of pump sizes and how many 20-watt solar panels each needs:
- 9-watt pump: 1 panel
- 12-watt pump: 1 panel
- 40-watt pump: 2 panels
- 50-watt pump: 3 panels
- 60-watt pump: 3 panels
- 100-watt pump: 5 panels
- 200-watt pump: 10 panels
- 300-watt pump: 15 panels
- 500-watt pump: 25 panels
In order to reduce the number of solar panels, your well pump requires, choose the lowest wattage pump you can. However, remember that the lower the wattage, the lower the water extraction.
Therefore, you must find a compromise between the amount of power your pump needs and the amount of water you need to be produced per minute. It is recommended that you speak to an expert in order to find the best pump possible for your needs.
Additionally, installation of a well pump that is solar powered is not the easiest of processes, so if you are not familiar with the process, it is highly suggested that you have a well technician do the job for you.
By having an expert install the well pump, you will ensure that it is properly installed and using your solar power as efficiently as possible.
Kind of Pump
The kind of well pump you use also affects the amount of solar you will need. The most common types are:
- AC Submersible Pumps
- DC Submersible Pumps
- Flexible Submersible Pumps
- Jet Pumps
- Specific Solar-Powered Pumps
AC Submersible Pumps
Well pumps that run on AC power are the most common type of pump. All houses that are connected to utility power in the United States run on AC, so nearly every water pump is AC powered.
Because these kinds of equipment are so readily available, they are more affordable than a lot of other types.
However, in order to use an AC pump with your solar system, you will need a high-power inverter as well, which increases the cost of the overall system.
Also, using an inverter increases the amount of power you need and, in turn, the number of solar panels you will need.
DC Submersible Pumps
Because DC pumps are less common, they tend to be a little more costly. However, DC pumps do not require an inverter, which means that DC pumps in general, require less solar power.
One drawback of DC pumps is that there are only models available in low to medium capacity, so if you have high water usage demand, you will have to go with an AC pump.
If you are choosing a new well pump to be connected to your solar system, many experts suggest that you go with a DC pump, if possible.
Flexible Submersible Pumps
There are a few pump models that run on both AC and DC power. These are great options if you want the pump to be powered by grid power most of the time and then switch to solar when you need it.
Because flexible pumps switch to DC when being powered by solar, they require less panels than traditional AC pumps.
A jet well pump is installed above your well and vacuums the water up into itself. Jet pumps need to be completely filled with water before they can then expel water out into a holding tank or directly where you need it.
The amount of solar energy a jet pump requires depends on whether it is AC or DC powered. An AC-powered jet pump requires more solar energy than a DC-powered jet pump.
However, because jet pumps expel water at high levels of pressure, you may not need a holding tank to provide the water pressure you require. If you do not use a holding tank, your well system as a whole will require less solar energy than it would if you did use a tank.
Specific Solar-Powered Pumps
Because of the increase in the popularity of solar power, some companies have now created well pumps that are solar-powered. These all-inclusive pump kits come with solar panels as well.
Because these types of pumps are designed to run from solar power, they usually require less solar power than other kinds of pumps. However, they also tend to have lower water pressure as well.
Solar-powered pumps are great for areas that do not reach the rest of the property’s solar electrical system. Such areas include farmlands and other pasturelands. Many farmers use these types of pumps to provide water to farm animals or to irrigate land.
Which Pump Is Best For You?
Though you may want to choose a well pump that requires the least amount of solar energy possible, remember that is not the only factor when making your decision.
For example, though you may want to go with a DC submersible pump, your home’s electrical system may not allow it without doing a complete electrical overhaul.
Additionally, the location and overall condition of your well may only allow a jet-powered pump. There are numerous aspects to take into consideration when choosing a well pump. As such, it is always recommended that you use an expert to help you decide.
Make sure to tell your well technician that one of the vital factors for you is how much solar power your well pump will require. Your technician will be sure to find you the most efficient pump possible that can be installed considering your well and electrical systems.
Use Your Current Pump
When connecting a well system to solar, many people think they need to install a brand new well pump and all the additional accessories it requires. However, this is not always the case.
In most situations, whatever kind of pump that is currently being powered by the grid can be converted over to solar. When doing this, make sure to consult a solar technician to be sure that the well pump gets enough power.
However, in general, the older your well pump, the more solar energy it will require. As such, depending on the age of your equipment, it may be more cost-efficient to install a brand new pump.
In order to make this decision, speak to your solar installer and/or well technician. These experts will be able to advise you on which is the best route for you to take to be sure that you are using your solar energy in the most efficient way.
Type of Holding Tank
When your well pump extracts water from you well, it usually places the water in a holding tank. There are two types of holding tanks:
- Non-Pressurized Tanks
- Pressurized Tanks
Tanks that do not use pressure to expel water from them require less power. In turn, your well pump system will require less solar power to run it.
Instead, non-pressurized tanks use gravity to expel water. However, because these tanks are not pressurized, your water pressure will be weaker.
Because these kinds of tanks do not use pressure, the placement of them is vital in order to get the best pressure possible. However, the farther the tank is from your well pump, the more solar power your pump will need in order to operate properly.
As their name suggests, pressurized tanks use pressure to expel water from them, which means you have higher water pressure. However, this also means that your entire well pump system will require more solar power to run properly.
As described above, yet another factor that affects the amount of solar energy your well pump will need is the location of your holding tank. Whether your tank is pressurized or not, the farther away the tank is, the more solar power you pump will need to pump the water to it.
And so, to reduce the amount of solar energy, your well equipment will require, place your holding tank as close to your well as possible. However, this may reduce the water pressure you get from your tank itself.
Most experts recommend finding a balance between the distance of the well to the holding tank to your home. The best balance is one that requires the least amount of solar power for each part of the well system while still providing strong water pressure.
The best situation is to design a well system at the same time you are designing the solar system of the house. This situation means that all the experts can consult each other to find the best design for your home.
Size of Well
The amount of solar energy your well pump requires is also affected by the actual size of your well. However, the size of your well depends on the following factors:
- Depth of Well
- Water Production
- Age of Well
- Static Water Level
Depth of Well
The deeper your well, the more strength your well pump will need to physically pump the water out of the well. In turn, your well pump will require more solar power to run.
The depth of your well will also affect the type of pump you need. Each type of pump requires different amounts of solar power.
How many gallons per minute does your well produce? The higher the amount of water production, the less your well pump has to work, which in turn means it requires less solar power.
If your water production rate is low, you may want to consider having a technician come out to redrill your well. This is an added expense but will mean your system will need less power to run in the long run.
Age of Well
As a well ages, water production tends to decrease. A decrease in water production is usually not very noticeable, but over time the effect can be cumulative.
For instance, though it may not seem that your well is producing less water this year than last year, if you compare this year’s production level to the one from a decade ago, the difference will often be quite extreme.
So, as your well ages, your well pump will need to work harder to extract water, which in turn means that your system will require more solar power in order to run.
Depending on the age of your well, you may want to consider drilling a brand new one. Though drilling a new well will be an additional expense, your well pump will do less work, which in turn means the pump will last longer and also need less solar power to run.
Many homeowners do not know the specific age of their well. If this is the case for you, you can call a well technician to come to your property and assess your well. Through ground tests and other factors, the technician will usually be able to estimate the age.
Additionally, you can try to contact your local permit office. Digging a well requires a permit to be pulled, and there should be a record of it. However, depending on the age of the well, there may not be a permit for it.
Moreover, though it is not by the rules, there are a number of illegally-dug wells that exist, which do not have a permit either.
If your municipality discovers you have an illegal well, they may require that you close it. As such, be sure to only consult your permit office if you know your well was installed legally.
Static Water Level
Another factor to consider is your well’s static water level or static head. The static head of your well is the distance from the well’s ground level to the top of the water.
This measurement affects the type of and placement of your well pump. The deeper your water level is, the more solar power it will require to extract the water from the well.
No matter whether you have a submersible pump or a jet-powered pump, the distance of the water level to the top of the pump will affect the overall amount of sun energy your pump will need.
If your static water level is low, your well technician may suggest redrilling your well to increase the water production and, in turn, the water head.
If redrilling is not possible, it may be more cost-effective to drill a new well than to get a pump powerful enough to take the water out of your current well.
Consult an Expert
Many well technicians offer consultations. They will come out to your property and fully assess your well. During this process, they will tell you about your water production rate, water level, and even water quality.
Some of these well technicians will also inspect your current well pump and let you know steps you can take to improve the efficiency of it.
Finding out this information is an excellent way to decide whether you should stay with your current well or have a new one drilled.
You can also ask your well technician to tell you whether he or she recommends you using your current well pump or installing a new one when connecting it to your solar system.
He or she will be able to recommend the best type of pump with the lowest energy needs possible.
Many technicians recommend that you run a full evaluation of your well system every 5 to 10 years, which will help to ensure your system is running properly.
New or Existing Solar System
Another factor that affects the amount of solar energy you will need to power your well pump is whether you are connecting the pump to an existing solar system or installing a brand new one.
When connecting your well to an existing solar system, you may need extra panels, depending on how your solar system is designed.
Because many solar systems are wired specifically for what they are designed to power at the time of installation, you may need to add an adjunct system to power your well. These adjunct systems usually require more solar power than other systems.
Most experts recommend that you connect your well pump to solar when you first install your solar system. Because the well pump will be included when you install the new system, the amount of solar energy needed will be the most efficient as possible.
Life of Solar Well System
A well pump that is properly installed to run on solar power will last more than 25 years if proper maintenance is done on it.
Another aspect to consider is that you can always upgrade your solar system and/or your well pump. As new technologies emerge, more efficient well pumps and solar panels are available on the market.
The more efficient the well pump, the less solar energy it will require to run it. And the more efficient a solar panel is, the more solar energy it captures, which means you need fewer panels to run your well pump.
How the water your well pump produces is being used affects the amount of solar energy you need for your well system as well.
For instance, if your well water is being used to water your lawn, you will not need to filter the water, heat the water, or store water. So, you will need less solar energy in general.
In addition, most sprinkler systems do not require a lot of water pressure, so you can use a less powerful pump, which needs less solar energy.
However, if you are going to be using your well water as a drinking source for yourself and/or pets or livestock, you may need to filter the water for impurities and also treat it with a water softener.
Pushing water through a filter requires a more powerful well pump, which needs more solar energy. The same is true for a water softening system. And, if you want the water softening system to run off of solar energy as well, you will need even more solar panels.
Moreover, if you are using the water for showers and cleaning, you will also need to heat the water. If you use an instant water heater, it will require a steady flow of water from your well pump itself. In turn, your system will need more solar energy.
If you use a traditional storage-tank water heater, your well pump will require less solar energy. The reason for this is because storage heaters have tanks that hold the water, so your well pump only needs to fill the tank over time.
However, the lower the power of your pump, the slower the storage water heater will fill, which in turn means it will take longer to have hot water.
Additionally, if you want your water heater to run on solar power, you will require more solar energy as well.
Number of Water Use Points
The number of places where you use water also affects how large of a well pump you need. For instance, if you only have a single sink that gets its water from your well pump, you will need a small piece of equipment and therefore less solar energy to run it.
However, if you are providing water for an entire home, with multiple bathrooms, sinks, and other water use points, you will need a larger pump, which will need more solar power.
In order to figure out the size of the well pump you will need, it is best to speak to an expert. Well technicians will ask you a series of questions, investigate your home’s water use points, and even look at your current water bill.
These experts will then use a formula to calculate the amount of water you and your household need, which in turn will provide your technicians with an estimated size of your well pump.
If you are installing your new well pump at the same time as your solar system, it is recommended that you have your well technician and your solar installers speak to each other.
By having both experts communicate, you will ensure that you get the best well pump for your home while still utilizing your solar energy as efficiently as possible.
The quality of your well water also affects how hard your well pump works, which in turn affects the amount of solar energy your equipment requires. For instance, water that is full of silt and other contaminants is thicker, which is harder for your pump to expel.
Depending on the natural quality of your well water, you may need to add a filter or filtration system to your well. As stated before, this will require that your pump work a little harder, which means it will need more energy from the sun.
However, if your water is naturally quite thick with dirt and silt, there are filtration systems that can be installed in the well itself to reduce how hard the pump will need to work.
In addition, because your well water is not being treated by any utility, it is vital that you have your water quality tested on a regular basis. Well, water can be contaminated by pesticides and other poisons, and the only way to discover this is to check your water quality.
Though it is an added expense of time and money to check your water quality regularly, it will cost less in the long run than an illness or other ailment that poor water quality can cause.
The amount of solar power you will need to run your well pump is affected by the wattage of the pump, type of pump you use, type of holding tank you use, the size of your well itself, and whether you are using a new or existing solar system.
How you use the water your well pump provides will also affect how much solar power you will need.
It may be a bit of a process to figure out the number of solar panels you will need and installing them to run your well pump. However, the money you will save by powering your water system via the sun will soon outweigh the initial time and trouble you invested.