Using Wind Power for Pond Aeration
If you live in a windy area, windmill aeration can be a great way to keep your pond water cleaner and healthier. Windmill pond aerators create circulation which helps pull cooler water from the pond bottom toward the surface where the dissolved oxygen is increased. At the same time, nitrogen and carbon dioxide are released to the atmosphere improving the pond water quality.
Windmill aerators add oxygen to the pond ecosystem only when the wind is blowing. If electricity is available, there are less expensive electric pond aeration systems that provide full-time pond circulation! If you need an off-grid pond aerator, there are many benefits associated with windmill aeration.
How do windmill aerators work?
A wind aerator is a descendent of the wind-powered water pump that was common around the world for years and can still be found providing water to cattle in remote areas.
- The basic components of a wind-powered aerator are:
- the vanes or blades that spin in the wind
- a simple air pump attached to the windmill shaft
- a tower to extend the windmill blades above the terrain to where the wind blows faster
- tubing that extends from the air pump to the ground level
- a one-way valve (check valve) to prevent water from flowing into the air tube
- weighted airline to be placed in the pond
- air diffuser(s) placed on the pond bottom that release fine air bubbles when the wind blows
When the wind blows, the air pump builds pressure forcing oxygen-rich air to the aeration diffusers on the pond bottom. As the air bubbles rise, pond water is drawn from the bottom of the pond or lake to the top where the majority of the gas exchange happens.
Advantages of windmill aeration for ponds
- Windmill aeration systems do not require an electrical supply
- Windmill air pumps are reliable and high quality with minimal maintenance requirements
- Most windmill aeration kits come in pieces so it can easily be transported to remote sites for assembly
- The windmill is quieter than an electric air compressor
- A windmill is an attractive feature next to a pond
- Windmill Aerators help to prevent fish kills
- In addition to ponds, windmill aerators can provide oxygen for wastewater treatment septic systems and other water treatment
- They are inexpensive compared to solar-powered aeration
Disadvantages of windmill aerators for ponds
- The aeration system only works when the wind blows. There is no battery backup to provide aeration when the wind doesn't blow.
- Some assembly is required
- The windmill aerator has lower pond air output than an electric-powered aerator
- Windmill aeration systems don't work well in low elevation areas (where many ponds are located) or in heavily forested areas where trees slow the wind speed
Things to consider when selecting a wind-powered aeration kit
- If possible, measure the windspeed at several locations around the pond. For best results, use a recording weather station so you have a longer time sample.
- The ground, trees, buildings, etc cause friction so buy the tallest windmill tower practical so that the aerator runs more often.
- The wind-powered aerator doesn't need to be placed right next to the pond. If there is a windier spot nearby, consider buying extra airline and putting the windmill aeration tower where there is more exposure to regular wind.
- Place the air diffuser(s) in the deepest water possible. The rising air bubbles will draw more water to the surface in deeper water giving the pond more dissolved oxygen.
- Anchor the windmill tower to a heavy, solid object. Be sure to pour a concrete base according to the manufacturer's recommendations or anchor the tower to existing bedrock. A poorly anchored windmill tower can result in serious injury and expensive damage.
Alternatives to Windmill Aerators
A solar pond aeration system is a viable alternative to a windmill pond aerator. The solar panels that power solar aeration systems provide a more constant source of power that may be desirable in some situations.
Even if there is no electrical power available right at the pond, a conventional aeration system may be possible. Most grid-powered pond aeration systems are able to force compressed air up to 2,000 feet through inexpensive direct burial airlines. It is possible to configure the aeration unit to supply a single airline to the pond edge, then use a manifold to split the airflow to multiple aeration diffuser plates spread out on the pond bottom.