Comparison of an Electrical, Solar and Windmill Aeration System

23 Mar

Aeration System Considerations

If you are considering purchasing a Lake Diffuser or Pond Diffuser aeration system to alleviate weeds, bacteria, and other pollutants from your body of water, you may be curious about the solar and windmill generated aeration systems on the market.  They seem so environmentally friendly, and require only the initial installation cost, but are they right for your pond or lake, and will they do the job?

Electrical Aeration System – Recommended

Hands down, the electrical aeration system will achieve consistent quality results every time; cost effectively, with easy installation, a hidden compressor which will not impede the view, and very easy maintenance.  Let’s explore the reasons for this statement.

Windmill Aeration System

How effective is a windmill aeration system in circulating the critical oxygen needed to restore a pond full of muck or thick algae?  The typical windmill aeration system runs only 7 hours a day, with battery backup handling the remaining 17 hours necessary for proper aeration.  However, the wind does not blow every day, so the windmill must be capable of storing and dispensing the necessary power for several days. Obviously batteries to supply all this power will be costly. A windmill large enough to supply the necessary power over a two-day period, using battery storage is extremely large, and extremely expensive.

Even when the wind is blowing and the mill is working to send vital oxygen up from the bottom of the pond, it is still not as efficient as an electrical pump.  Some windmills create a blast of air on every full-turn of the fan and others send air on every half turn. Calculating the actual output is not easy because the wind is constantly changing, but regardless, the mill will not provide a constant flow of bubbles.

The windmill aeration system tower must be strong enough to withstand severe winds and be anchored securely into the ground so that it does not blow away. This usually requires a 20’ – 25’ tall windmill and at least a 10’ by 10’ slab of concrete to anchor it on.  Most windmills have a fan diameter from 65 to 72 inches. Almost all windmills have 12 fan blades.  Many windmill aeration system manufacturers say that the mill will operate with as little as 5 mph winds, but this is rarely the case.  The resulting structure next to the pond can look similar to the eyesore of a cell phone tower.

Installing the windmill aeration system can be very complex and require several days. The final cost in time alone can make it a better deal to hire the experts to build and install the system.   In addition, the diaphragm on the windmill aeration system will require maintenance after a few years of service requiring that the windmill tower be lowered to be able to open and adjust the windmill head to replace the diaphragm.

Windmill aeration systems do supply more power than solar systems, but since a typical solar power aeration system generates less than 5 PSI they really are not an alternative to either a windmill or an electric aeration system.

Sometimes the cost of the windmill aeration system may make it seem like the best deal.  Remember that the best deal isn’t always the cheapest. You can probably save a lot of money by buying a windmill aerator system on eBay, but you won’t get any customer support when things go wrong.

Solar Aeration System

Typical costs of solar cells (not counting cost of batteries & converters) needed to provide 30 kW-hrs per day or 1.68 hp (typical use by an American family) is about 14 cents per kW-hr over a 20 year useful life of the cells. We get no more than 5 hrs of effective sunlight a day here in Pennsylvania. In areas like Arizona, you can do a little better. An aeration system must be operated twenty-four hours a day to be effective, so a large bank of storage batteries is necessary, along with converters necessary to change low voltage DC to 120 volt ac power.

You may consider solar power a good enough trade for clean, “free” energy. To do that, you’d have to come up with about $30, 000 (plus installation costs) up front, instead of paying the electric bill monthly over 20 years. And a large, often unsightly surface area for the solar cells is required.

Bob Laing is an engineer with more than 30 years of experience in aeration system design, improvements & Pond weeds control with aeration systems.   He is currently a consultant for CLEAN-FLO, a leader in pond and lake aeration systems

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