I am using a solar power system to provide electricity to the various pumps that help the tank stay healthy for the shrimps. But here in Missouri, we have had unusually high temperatures for May and June. The shrimp do well in warm water temperatures (see page 9 of ON THE GROWTH RATE OF THE FRESHWATER PRAWN, MACROBRACHIUM ROSENBERGII), and the best temperature for maximum growth is 84o F.
However, in our storage shed that is used to house the electronic components of the solar power system, the feed, water testing kits, and air pumps, the temperatures exceeded 110o F on several days. These can cause early failure of two primary components of the system, the solar controller and the inverter. I had already installed a USB-powered fan to cool the solar controller but not anticipate the need to control the internal shed temperature. But the power inverter failed.
I was able to identify a major source of the heating in the shed. I had the air pumps inside the shed and it turned out that the models that I had used were noted (by user reviews) to “run hot”. Indeed, when running, I noticed that the temperature around the pumps was running about 98o F (significantly higher than the outside temperature). I built a shelf outside of the shed to mount the pumps. I also replaced the pumps with pumps that user reviews didn’t mention as “running hot”.
I also built a “swamp” cooler for the inside of the shed. A “swamp” cooler is a cooling unit that uses water evaporation to cool air. As water evaporates, it removes energy from the air around it. Forcing a stream of air across a water-saturated mesh has the net result of the air leaving the cooler at a significantly lower temperature. The only drawback is that this works best when the outside humidity is less than 80%. Here is MO we consistently run 50% – 70% humidity, but any cooling can be welcome in this situation. Here is a link to a video the shows how to construct a swamp cooler from a 5 gal. bucket (https://www.youtube.com/watch?v=aHbQYajfGqM). I modified the cooler by nesting two 5 gal. plastic buckets so I could have more water for the pump. I also used a fan and a water pump that are powered via USB (I have two USB ports on the solar controller). After installing and running the cooler, the inside shed temperature has not gone above 95o F with the air pumps moved outside.
The failure of the inverter was most likely because of the high temperatures. Converting 12 v DC to 110 v AC releases a great deal of energy. Inverters have internal switched that will turn off the power conversion when the circuit board gets too hot. If this function is used too often, the switch will fail and the associated failure alarm will be triggered even if no devices are connected to the inverter. This happened to my inverter and I ordered a replacement with a higher wattage rating.
Fortunately, my battery float charger has a direct AC power cord and I am able to run the pumps from that until I get the new inverter installed.