Backyard Aquaponics
A place to discuss aquaponics

Yeah agree, don't bother attempting heating with solar panels.. go evacuated tubes instead.

As mentioned the battery in my system has not dropped below 80% for the couple of months it's been running, including long stretches of overcast weather. Normally it's running at about 90%

That pump must be pretty efficient to only use 0.042kWh overnight (to stay above 90% SOC)! I guess you are running F&D with a short on time? My 125W, on 15 mins/hour overnight, uses about 10 times that.

This DC pump draws 5w at 12 volts, pumping 980 lph

.. or in 24 volt Configuration 21.5w @ 1560 lph

Earliest I've checked it in the morning is probably around 9am, so maybe it's had a bit of charge by then.. not sure what it gets down to in the early hours of the morning

DC pumps do tend to be a lot more efficient than AC pumps, what brand is it? Any reliability issues so far?

More efficient they might be.... but reliability seems to be a real problem.... probably because most of them just aren't designed to run continuously... or even for frequent hourly/daily periods....

Mine is a REEFE RS980 DC pump.

Glad I'm not the only one to have suffered from failed DC pumps. Have tried a few, this brand seems ok so far and have used a few of them

I have this one, and it has been trouble free so far. It is a brushed motor, but running good.

http://store.waterpumpsupply.com/mppufrse316s8.html

I've had good luck with Rule brand pumps. They're designed for continuous duty and can run dry, plus they're cheap

http://store.waterpumpsupply.com/ru12vodcnobi.html

Can someone explain what evacuated tubes are or post a link to a go explanation?

I was hoping for a direct link...

sort of like http://en.wikipedia.org/wiki/Solar_thermal_collector#Evacuated_tube_collectors

but maybe a more personal touch...

hehe us aussie males aren't well known for many words when less can do the job

Have you got a handle on evacuated solar tubes now cjinVT?

They are basically a new generation solar heating technology, consisting of a series of glass tubes all connected together which are very very well insulated, usually installed on a house roof.

They still work well in frost and, due to the conical nature of the tubes, at different roof angles (to the sun) where older solar heating systems were less efficient

You would proabably enjoy this for a read, CJ. Its been done and documented before.

viewtopic.php?f=8&t=3976&p=142855&hilit=evacuated#p142855

That was perfect Charlie thank you!