2.2 amp 12v pump

[villa frontera]

Hi All
I have a solar hot water panel roof mounted and I have a 2.2amp pump installed on the circuit pipes to the floor mounted storage cylinder.
I would like to run this pump either from a pv panel or via a 220v to 12v transformer.
if I run it from a panel as the sun goes down the pump will stop which is good. If I run it via a transformer then it will need to be controlled by a timer. If I go down the panel route what size panel is suitable for this 12v 2.2 amp / 26.4 watts pump?

your experienced answers will be appreciated

 

[Shimmy]

My solar hot water system uses temperature sensors at the tank and the roof, and as much as I thought it could be controlled more efficiently with some other scheme, hands-down this is the best way. It cycles on for about 3 minutes whenever there is a 10°C delta between the tanks and panels, usually 10-15 times a day. Running continuously when there is sun will likely cool the tank at times, especially if your pipes are not properly insulated.

 

[houseofancients]

My solar hot water system uses temperature sensors at the tank and the roof, and as much as I thought it could be controlled more efficiently with some other scheme, hands-down this is the best way. It cycles on for about 3 minutes whenever there is a 10°C delta between the tanks and panels, usually 10-15 times a day. Running continuously when there is sun will likely cool the tank at times, especially if your pipes are not properly insulated.

Can you elaborate on what controller you are using ?
Is it an off the shelf one, or specific to the hotwater system ?

 

[villa frontera]

My solar hot water system uses temperature sensors at the tank and the roof, and as much as I thought it could be controlled more efficiently with some other scheme, hands-down this is the best way. It cycles on for about 3 minutes whenever there is a 10°C delta between the tanks and panels, usually 10-15 times a day. Running continuously when there is sun will likely cool the tank at times, especially if your pipes are not properly insulated.

Hi My location is southern Spain and the sun shines All the time and this system is only for occasional family guests in a small guest house. As the evening comes and the sun goes down my thought is if I installed a suitable PV panel it would cease circulating. Yes the pipes are insulated. The hot water cylinder has a capacity of 250ltrs.Our main house has a bought in system that perfect for all year full residential use. In a nutshell the system in question is just for one or two daily summer showers. my plan was to make it as basic as possible.
Cheers
Phil

 

[yodamota]

Why not just use a 30 watt 12v panel? Our garden water pump runs off 130w of solar direct from 3 - 12v panels.The pump runs at 10 amps 12v nominal. works like a charm.

I have a 120v light switch in the positive line to shut it off when not needed. And the pump came with a 15amp inline fuse.

 

[chrisski]

If I go down the panel route what size panel is suitable for this 12v 2.2 amp / 26.4 watts pump?

A south facing 100 watt panel in the sun can reliably deliver 2.2 amps between 10 am to 2 pm the shortest days of the year.

Add an east and west facing 100 watt park in parallel, I get that 2.2 amps between 8 am and 4:30 pm. In summer, much longer of course.

If cloudy, 2.2 amps won’t be produced and it shuts down.

A 50 watt panel would reach that amperage, but unreliable.


What ifs:
-Make sure the pump can handle the voltage or add a converter.

-I’m not sure of the surge of the pump, and as an inductive load you may need more than 2.2 amos if panels.

Since the ideal system would have a battery, probably would be cheaper with an AC install.

 

[Shimmy]

Can you elaborate on what controller you are using ?
Is it an off the shelf one, or specific to the hotwater system ?

Off the shelf-- mine is a SunEarth controller. Their modern ones are variable speed drive and have a few more bells and whistles, but the basic one does the job.

 

[houseofancients]

Off the shelf-- mine is a SunEarth controller. Their modern ones are variable speed drive and have a few more bells and whistles, but the basic one does the job.

Ah, yes, here we know these as STECA controllers