Solar setup newbie help

[ard2dabone]

Hi all

I'm looking to set up a solar pump for water feature/fountain. Looking to set up panel, controller and battery setup.

My question is, if I have a very small 8w or 18w pump. How do you regulate or set parameters (voltage/amps) for the load output between a controller and pump device as not to burn out the pump motor. I have no idea if this is obvious or dumb, I really know nothing about electronics.

Kind regards

Aaron

 

[Bob B]

As long as you are providing the pump with the voltage it is rated for ..... The design of the pump itself will determine how much power it uses.
You will want to fuse the circuit, but that is a separate issue.

 

[MisterSandals]

My question is, if I have a very small 8w or 18w pump. How do you regulate or set parameters (voltage/amps) for the load output between a controller and pump device as not to burn out the pump motor.

Not a dub question at all. The pump actually pulls the amps it needs and will be happiest with its rated voltage.

So the question is, what voltage do your pumps accept. And be sure to distinguish between AC and DC current.

Let’s do some math:
18W pump running 10h per day is 180Wh

If you get 5 h of quality sun (which is hard this time of year):
180Wh / 5h = 36W solar panel.

To store half of this energy (the 5 hours without quality sun) you need to store 90Wh (usable) in battery(s).

For a 12.8V battery, 90Wh / 12.8V = 7Ah of usable battery.
Since a lead battery can only be discharged 50% (down to 12V), you would need (at bare minimum and everything at 100% efficiency) a15Ah lead battery.

For lithium, close to 7Ah battery

Helpful?

 

[MichaelK]

Here is an important question. Do you want a pump that's running 24/7 to keep your fish alive, or just something for esthetics, that runs a fountain in the front yard? There are DC pumps that would only run while the sun is shining. That would be a very simple setup. Running an AC pump will be significantly more complex.

 

[ard2dabone]

It's just a pump in a water feature for aesthetics.
So I could connect any 12v DC pump and don't have to worry about wattage or amps or it burning out?

I don't need it going all night, just daylight hours really, maybe early evening.

 

[MichaelK]

It's just a pump in a water feature for aesthetics.
So I could connect any 12v DC pump and don't have to worry about wattage or amps or it burning out?

I don't need it going all night, just daylight hours really, maybe early evening.

That makes you life much easier. You just have two numbers to pay attention to now, the voltage, and the amperage. Let's say you select a DC only pump that needs 1.5A at 12V. Let's say you wire it into a standard 100W panel putting out 5.5A at 18V. The pump is the load, and will tend to drag the voltage down to the level the pump operates at, or say 12V. So, you'll have a maximum of 5.5A running at 12V.

But, during the day, the panel will not be producing 5.5 (if ever). It will make the amount of amps proportional to the intensity of the sun, and the angle of the sun to the panel. So, at 8am, when the sun is lower in the sky, and at almost a 90 degree angle to the panel, your output will only be a tiny fraction of full output, say 5-10%.

So, at 8am, the panel will be feeding maybe only ~0.5A instead of 5.5A. The DC motor in you pump might run very slowly, and pump a small volume of water, or it might get physically damaged by low amperage that is not high enough to get the motor spinning. You should check this before you buy. I can't tell you which pump motor will be fine, and which will not. Check with the manufacturer for that.

 

[Hedges]

Some motors will run OK as PV power slowly ramps up and down. Some won't. I've tested brushless DC fans of both types with an adjustable DC supply at the surplus store before buying.
Brush type motors should generally work.

Something called a "linear current booster" can stretch hours of operation, but costs I see are excessive for a water feature, more for household water pumping.

Use two PV panels, one aimed around 10:00 AM sun and one around 3:00 PM sun, wired in parallel.
That will provider power earlier, later, and more uniform during the day.

 

[jz fo]

Some motors will run OK as PV power slowly ramps up and down. Some won't. I've tested brushless DC fans of both types with an adjustable DC supply at the surplus store before buying.
Brush type motors should generally work.

Something called a "linear current booster" can stretch hours of operation, but costs I see are excessive for a water feature, more for household water pumping.

Use two PV panels, one aimed around 10:00 AM sun and one around 3:00 PM sun, wired in parallel.
That will provider power earlier, later, and more uniform during the day.

Can you help me set this up please, having major troubles!

 

[jz fo]

Can you help me set this up please, having major troubles!

 

[MisterSandals]

Can you help me set this up please, having major troubles!

Is there a reason you are adding to this thread? You should start a new thread with a descriptive title so your issue does not get mixed in with the existing thread.

You'll have to be more descriptive than "having major issues" for someone to know what you have and possibly figure out what to do.

 

[jz fo]

Is there a reason you are adding to this thread? You should start a new thread with a descriptive title so your issue does not get mixed in with the existing thread.

You'll have to be more descriptive than "having major issues" for someone to know what you have and possibly figure out what to do.

Thankyou, new to all of this!

 

[MisterSandals]

You should also post in the DIY Wind Turbine section (and put "wind turbine" somewhere in your title).

DIY Wind Turbines and Hydroelectric

diysolarforum.com

 

[jz fo]

Awesome thankyou!