June 07, 2021
DIY Solar Pond Aeration
A basic overview of solar aeration system options, components, and choosing the best solar pond air pump.
Is your pond far away from a power source?
Are you looking to utilize clean renewable energy?
Are you looking for potential long-term cost effectiveness?
Perhaps solar pond aeration is a good option for you. However, setting up a system can be complicated, expensive, and time consuming. Below we dig into the two standard system options, touch on common components needed, and discuss solar pond air pumps.
Solar Systems Options
Solar powered aeration system with battery back-up:
If you want your solar pond air pump to run most of the day, then a battery back-up system is necessary. In addition to running the air pump, the solar rays charge the batteries in the cabinet. Once the sun goes down – or if it is a cloudy day – the pump will continue to run, on average a total 16-20 hours a day. The downside is that these systems are significantly more expensive than direct drive solar aeration systems. They require batteries, a charge controller, and other components not necessary in the direct drive system. Considering the number of components, maintenance can be costly long-term. Initial set-up is also much more complicated and time consuming.
Direct drive solar aeration system:
Direct drive solar aeration systems use the suns energy to run the aeration system without the use of batteries as a back-up. As a result, the solar pond air pump only runs when it is sunny – about 8 hours a day in most locations. Of course, latitude and the time of year can impact the runtime. The major advantage of this type of system is that the initial set-up cost is significantly less than a battery back-up system. Additionally, the system will require less maintenance as there are only a few components that may need to be repaired/ replaced over time. The downside is that the pump will not aerate the pond 24/7. However, there are professionals in the pond industry that believe 8 hours is enough to turnover and increase oxygen levels to clear up the pond and provide a healthy environment for fish.
Main components of a direct drive solar aeration system:
There are two common types of panels: polycrystalline and monocrystalline. Polycrystalline is less expensive than the alternative but not as efficient. In many southern states – or areas that get abundant sunshine – polycrystalline may be a good option. For those in northern states or states that have less sunlight, most experts suggest spending the extra money for monocrystalline panels to maximize energy efficiency.
Choosing the number of panels to run your solar pond air pump can be tricky. If for example you want to run a HIBLOW HP-80 air pump (71W) for a ½ acre 8’ pond, it would be easy to assume that (1) 100W panel would be enough. Unfortunately, that is highly unlikely regardless of where you live. Typically, these panels are spec’d at 100W in a lab setting. In a real life setting 100% efficiency is not realistic even if you have the panel at the right angle at peak sun. Additionally, an inverter is needed (more info below) to convert the DC sun energy to AC which is required to run the aerator. The inverter may reduce the efficiency by 10-15% alone. After testing some pumps here in our home state of Michigan, we found that you need 3 100W panels to run the pump consistently. Generally, we suggest contacting a solar expert in your area to consult with, but there are formulas in which you can make the calculations yourself.
Being able to adjust the angle of the panels throughout the year is essential to maximize energy efficiency. Therefore, any DIYer should do their due diligence when mounting panels so that the sun can be fully utilized throughout each season of the year. In North America, all panels should face south and be adjusted accordingly based on latitude and season.
The DC energy from solar rays will not run the AC driven HIBLOW air pump. As a result, an inverter is needed to convert the direct current electricity to alternating current. As mentioned above inverters reduce efficiency, especially the cheaper ones. Like anything in life, quality makes a difference. One thing to consider when buying an inverter is the low voltage shut off. Some inverters will shut off and an alarm will go off until the inverter is manually reset. Many experts suggest installing a relay between the inverter and the solar panel which will not allow the inverter to fall below the shut off voltage. A timer relay is also an option if you want to control the time the system will run each day (especially for battery back-up systems).
The pond aerator is the heart of the system. Choosing the best one for your application is critical to its efficiency. Some companies use DC driven air pumps for solar applications so that an inverter is not needed, however DC pumps are typically not as energy efficient, they do not last as long, and are not easy to rebuild like a HIBLOW. In a real-life setting, HIBLOW manufacturers the most energy efficient linear air pump in the world. We offer three models: HP, WG, XP. The HP is great for ponds beyond 6’ in depth. We recommend the WG or XP for ponds under 6’ – both are extremely energy efficient and perfect for solar. Check out the following link for pump sizing and more information: https://www.hiblow-usa.com/applications-guide/pond-aquaculture/
Cabinet or enclosure:
Keeping the electrical components out of the elements is important. When considering your options, keep in mind that the aerator needs air circulation. Many times, pond air pumps are put into small spaces allowing for little air circulation. Therefore, the pump runs much hotter, and the diaphragms will not last as long. An inverter also produces heat. For best results keep the components out of the elements but allow enough venting to keep the pump as cool as possible.
Tubing and diffusers:
Check out the articles below for our recommendations:
Running tubing long distances is also an option when setting up an aeration system. Running 2” pipe (to mitigate friction loss) up to 1,000 feet from the power source should not impact the pumps performance and is likely a much cheaper option than a solar aeration system.
Battery back-up solar aeration system set-up:
For detailed information on battery back-up systems, check out the following video from a DIYer who installs a HIBLOW HP-80 in Northeast Ohio.
Additional Recommended Content:
Before you buy information and suggestions:
DIY Solar Power Forum
Author: Mike Miner
June 07, 2021