Backyard Aquaponics
A place to discuss aquaponics

I hope it shuts off in a blackout, otherwise it could kill a linesman... or the death lead (live male plug) could kill anyone who touches it, if it doesn't shut off immediately on unplugging.

It will undergo further testing today

BTW there are plug and play panels ie the inverter is in the panel so the panel puts out 240v http://www.tindosolar.com.au/our-austra ... olar-panel

ok, but be aware those things are illegal to connect to the mains power supply... use at your own risk!

See above.

Its not the risk I am worried about only the reliability.

Yes there are approved microinverters available now, but they are expensive.

However, "cheap ebay electronics" and "reliability" should not generally be used in the same sentence

If I could afford mil spec I would do it

The inverter does shut off immediately if mains power fails, I am waiting to see what it does when light gets below a certain level. I am a bit worried about ambient in Perth summer; the fan kicks in, flat out, on what appears to be a coolish day for us at 11 am (I doubt a sophisticated control).

I suspect they've done what many designers do and neglect ambient air temperature entirely in favor of duty cycle. Several products I've been on the design team for have done this, as it is more predictable for designers. They know regardless of environment that there will be a certain amount of airflow over the parts when the system is at a certain load.

It was always strange when I was testing satcom (satellite communications) equipment to see the fans kick on when the chamber was at -20C

As far as MPPT goes, there is a lot of half truths floating around about them. The important thing to remember is that they are maximum power devices. They are switch mode power supplies that take a variable-voltage input from the panels and produce the most power (remember Ohm's law? E^2/R or I^2R or EI) for the input. The rating of the panels is the combination of open circuit voltage (37 in this case) and short circuit current to give you your 130W..

If you were considering switching between solar and mains for your pumps you could do it with a couple SPDT relays, use some regulated DC off the solar system to hold the relays in, keeping the pump on your inverter. When the solar power voltage drops the relays release switching the pump back to mains.

Cheers
KS

Thanks KS, I often wondered about the fans on certain things. I had assumed they were like my controller for my go faster car, small programme that measured ambient, load etc then decided whether to spray my intercooler.
Problem with fans is they blow and deposit dust which is a bit self defeating.
I am still looking for a reasonable grid tie inverter for the panels as I am happy to slow the meter to compensate for the pump etc pull and use a back up battery inverter for power outs. Its a bit like a UPS and will charge and maintain the batteries and switch for power outs.

I have a small test system running on a 80Wp panel, 125Ah deep cycle and a modified UPS. Works pretty good. The UPS battery was dead, so I opened the box, got the battery out, lengthened the cables, got the bloody piezo beeper out and hooked it up to the 125Ah. Works as a kind of off-grid system, but will also work when plugged into the grid. The charger is not doing much though on such a comparative heavy battery, charging has to come from the PV panel.

Scan around for a broken UPS, it's mostly the battery that gave up.

A great, and much safer idea than DIY Domani! Unless you're a real pro, messing around with the mains isn't something I would recommend. Depending on the size of your UPS that you find, it may or may not tend the battery. One thing to remember however is that the battery needs to be rated for "deep cycle" and multiple cycles. Marine batteries are good for that, and much cheaper than the proper solar batteries or "golf cart batteries" that are purposely designed to be used that way.

I may actually consider going that route on my pilot system that I'm putting together, as broken UPS can be common and usually free.. and I do have a few batteries laying about.

+1 for the UPS idea, just make sure that the VA rating on the UPS output is greater than your system requirements.

Cheers,
KS

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Was that a question Bullwinkell?

If so, my mate 'borrowed' some of my panels and is currently running his bedroom off the grid (TV amp computer etc) His experience to date has been interesting and the biggest drawback has been the reliability of his second hand battery bank, however he has a couple of big Trojans that seem to hold up.

I haven't done anything as I will wait till he gets it right.

That was meant to be me saying that second paragraph ...

<quote>Lets just assume I don't have a lot of money and will only be able to buy one thing. I have the pump, I can easily get a small inverter, the battery is debatable. I am happy to only run daylight hours.
I am fairly good at modifying stuff.</quote>

..was the most concise normal English paragraph I've ever had the pleasure of reading.

I'm not sure why I sent a dot in it's place.

in Oz, can you get any solar rebates for non grid tied systems? Things like adding a solar system to your house boat so you don't burn diesel for lights etc?

Or for an off grid aquaponics system?

It seems if you are doing something that uses power, and you can go solar, the same rebates should exist because its all about the carbon.

I'm increasingly being pushed towards going off grid. A new piece of land I looked at the other day has power at the gate but its still expensive to get the power connected and then to the site.

Since I want solar panels to reduce my grid use, I already need a back up generator and I already need a control system to switch between the two the extra money that I would have to spend on a small battery bank and second generator is looking less and less than what it would cost me to connect to the grid.

So it seems that no matter where I go I will be using some sort of hybrid system.