Solar Aeration: Is It Right For Your Pond?
By Industry Expert Shannon Junior, Aquatic Ecologist
If you are a frequent reader of the SOLitude newsletter or blog, then you are undoubtedly familiar with the numerous benefits of aeration for your pond or lake. In a nutshell, dissolved oxygen is the single most critical water quality parameter affecting the overall health of a waterbody. Adding an aeration system to your pond will increase the dissolved oxygen level, reduce the effects of nutrient loading by accelerating the breakdown of organic matter, and prevent the release of toxic substances from the sediment into the water column. An adequately aerated pond is less prone to harmful algae blooms and provides a healthy environment for fish and other aquatic organisms.
For most waterbodies, a submersed diffused air system is the most cost-effective aeration strategy, both in terms of the initial investment and the long-term operational cost. This type of aeration system utilizes pumped air to de-stratify the water column and to infuse oxygen into the pond. The typical configuration involves an air compressor that sits on the shore and pushes air through subsurface tubing to one or more diffusers located on the bottom of the pond. The membrane on the diffuser breaks the air into tiny bubbles that are released into the pond. As the bubbles rise to the surface, they carry the hypoxic (low oxygen) bottom water upwards, where it is mixed with the oxygen rich surface water. This constant vertical mixing causes the water column to de-stratify, allowing harmful gases to be released into the atmosphere. It also brings more of the water in the pond into contact with atmospheric oxygen, which increases the overall dissolved oxygen concentration in the water column.
Although diffused air pond aeration systems are less expensive and more energy efficient than surface aeration systems (i.e., fountains), many of our clients find that the cost to bring electrical service to the edge of the waterbody is exorbitant. This can be true for rural farm properties where the nearest transformer is hundreds of yards away, as well as for metropolitan sites where the existing infrastructure provides obstacles to installation. In these situations, solar powered aeration systems may be the ideal solution.
The configuration of the solar system is similar to the traditional system, except that the compressor is connected to solar panels instead of an electrical power source. As with any solar powered equipment, the weather can be a limiting factor in how well the systems operate. One manufacturer includes a battery back-up system with their aerator that provides the capability for it to run for 20 hours per day and for up to three days without any sunlight, although these systems are significantly more expensive than traditional aeration systems. Another manufacturer offers a battery-free system that is comparable in price to an electrical system, although it will obviously be more limited in the hours that it can operate.
For sites where electrical power is easily accessible, the traditional diffused air systems remain the most reliable and affordable aeration option. However, a solar pond aerator may be a good choice for properties where obtaining electrical service is challenging, or where there is a heightened concern for environmental sustainability and “off-the-grid” operation. If you are interested in learning more about solar aeration, a SOLitude Lake Management representative can help you choose the best system for your site and budget.
Shannon Junior is an Aquatic Ecologist with SOLitude Lake Management .Since 1998, SOLitude Lake Management has been committed to providing full service lake and pond management services that improve water quality, preserve natural resources, and reduce our environmental footprint. Services are available throughout the Eastern United States. Fisheries management consulting and aquatic products are available nationwide. Learn more about SOLitude Lake Management and purchase products at www.solitudelakemanagement.com.