Advice for simple set up for solar pump

[mixed]

I have a 5,000 ltr tank and I want to pump to it from a nearby well, then use this for both domestic and garden. I'm looking for simplest solar pump set up to achieve this. If it was running 5-8 hrs a day, the pump wouldn't need much volume. Head is 6m - 8m.

 

Can anyone offer advice on thehe simplest set up for this? Something that could be added to later with other pumps and possibly batteries.

 

Thanks in advance for any replies.

[Crossy]

Do you have mains power on site?

 

If so, use it and a mains pump, your wallet will love you for it.

 

By all means supplement it with a couple of panels and a grid-tie inverter for the green feeling.

 

[mixed]

I would have to buy a pump. At the moment we are using town water, which is unreliable in the hot season. So I am looking to supplement as you've suggested. I understand simple solar pumps and panels are not that expensive?

[Crossy]

OK, how much volume do you think you actually need?

 

What sort of budget do you have in mind?

 

[Crossy]

This chap is cheap, no idea of the quality of course.

 

https://www.lazada.co.th/products/solar-water-pump-qb-60-150w-dc12v-series-mtec-i1411606108-s3624822463.html

 

Add a 300W panel for about 3k Baht.

 

[mixed]

Thanks Crossy, I would need enough to pump 1,000 lts in about five hours.

Budget is basically as little as possible, while still being reliable and durable enough.

The pump you have posted looks interesting. Would I only need that and a panel?

 

Prices for panels vary a lot. A 300w can be as low as B1,850 (regular price) or for B3,190 I can get 330w, which apparently is a 60% discount.

 

First question would be exactly what is needed,

Second is how to work out if it's decent quality.

[bankruatsteve]

33 minutes ago, mixed said:

Second is how to work out if it's decent quality.

Chinese products can be with dodgy quality but seem to be getting more reliable.  MTEC has mostly good reviews.  But, a 1 month warranty might be an indication.

[Crossy]

It could be worth messaging the pump seller to ask what panel size they recommend.

 

The problem is that there are many variables including the amount of sunshine. 

 

I'd be tempted to add a 12V battery and a small charge controller to avoid over-powering the pump when the sun was really bright and allow the pump to keep pumping when the sun is hiding for a bit.

 

But of course this all adds cost.

 

How I would do it:-

 

For about the same money you can get a similar sized mains pump. No panel, battery etc. needed and it doesn't go to sleep with the sun. Add a float switch to stop it when the tank is full and you're good to go.

 

Then get a couple of cheap panels and a baby 1kW grid-tie inverter to offset your power bill even when the pump isn't pumping.

 

[SomchaiDIY]

Includes also item list in video

 

 

 

 

 

[Crossy]

3 minutes ago, SomchaiDIY said:

Includes also item list in video

 

Looks a handy system, any indication of cost??

[mixed]

1 hour ago, Crossy said:

For about the same money you can get a similar sized mains pump. No panel, battery etc. needed and it doesn't go to sleep with the sun. Add a float switch to stop it when the tank is full and you're good to go.

The tank itself is stored energy, during the rainy season, when there's lots of clouds, the water will only be for household use. The cost may be similar to a mains pump and while there will only be a small saving on power bills, no outside inputs are needed, we will be self sufficient for water. Some days through the hot season there's no town water. Another thing is the well can run dry if we pump to fast, so slow pumping is best, with gravity fed to the house and garden.

[mixed]

1 hour ago, Crossy said:

 

Looks a handy system, any indication of cost??

Somchai goes through the costs at 4;17.

2 x 340w solar panels = B7,450

Pump and  controller = B8,280

TOTAL = B15,730

 

The pump is 550w and without batteries will only work with the sun. My idea is to have a much cheaper system, the tank will fill slowly, but it around 3m high, so hopefully good pressure. The tank I got free, if I had to buy it then the system wouldn't be affordable.

[Crossy]

Back to the original pump we looked at, 300W panel, small battery, 12V charge controller.

 

The panel should run the pump on it's own, but I'd worry about over driving in bright sunshine. 

 

Try it and see.

[mixed]

2 minutes ago, Crossy said:

Try it and see.

I will take your advice and go for the controller. They are fairly cheap. So the system could be done for around B5k?

 

The only thing is getting decent hardware, it's very difficult to know with Lazada, going  by price doesn't work as sometimes the same item is being sold at half the price by others.

 

How about for solar cells? I know that mono is better. Is there anything else I need to look for, such as brands etc?

[Crossy]

1 minute ago, mixed said:

How about for solar cells? I know that mono is better. Is there anything else I need to look for, such as brands etc?

 

Much of a muchness really, I wouldn't bother paying extra for mono, you're not looking to get every last watt out of the system. We have a mix of cheapo and mid-priced panels, they all seem to perform pretty well.

 

By the way, don't be tempted to run your solar controller without a battery, many of them emit the Magic Smoke if connected like that.

 

[bankruatsteve]

25 minutes ago, mixed said:

the tank will fill slowly, but it around 3m high, so hopefully good pressure.

Maybe to slowly fill a bucket.  You need 10m above tapping point for just 1 bar.

[mixed]

4 hours ago, Crossy said:

By the way, don't be tempted to run your solar controller without a battery, many of them emit the Magic Smoke if connected like that.

 

Would this need to be an expensive battery? I really know very little.

[BritManToo]

48 minutes ago, mixed said:

Would this need to be an expensive battery? I really know very little.

Any old 12v car battery (or 2) would do.

Quite a lot of the charge controllers need 24v.

It doesn't need to hold a charge, just dissipate any unwanted energy.

Edited November 9, 2020 by BritManToo

[Elkski]

Op states a desire to pump 1000 l 8 meters high.   In 5-6  hours.   These numbers  plus the  pipe  friction losses are all you need to calculate  energy required.  Then figure out panel wattage  required.   Do you currently have a well pump? Submersible or not?  Is it really only 8 meters from well bottom to top of the tank?   

[Crossy]

9 hours ago, mixed said:

Would this need to be an expensive battery? I really know very little.

 

Not really. As @BritManToo says and old car battery would do to start with. It needs to work well enough for an auto-sensing charge controller to determine the system voltage when it starts. Obviously a better battery would allow the pump to run when there was less sun.

[mixed]

Quote

Op states a desire to pump 1000 l 8 meters high.   In 5-6  hours.   These numbers  plus the  pipe  friction losses are all you need to calculate  energy required.  Then figure out panel wattage  required.   Do you currently have a well pump? Submersible or not?  Is it really only 8 meters from well bottom to top of the tank?   

This morning it is 5 meters from water in well to the top of tank, this will drop at least another 3m, so I would probably be better calculating for 10m.

 

Quote

Not really. As @BritManToo says and old car battery would do to start with. It needs to work well enough for an auto-sensing charge controller to determine the system voltage when it starts. Obviously a better battery would allow the pump to run when there was less sun.

At some point I would like to run our aquaponics system off solar, but that is well into the future. Right now I'd like the simplest set up for filling the tank, with the possibility of adding batteries etc. later.

 

At a glance, controllers range from B120 to over B2k, it's difficult to know what suits my needs and will not become redundant if I add.  For B1,200 this controller uses a battery and also provides power outputs. Would be OK to begin with? Later I could add proper batteries if needed.

[Crossy]

46 minutes ago, mixed said:

For B1,200 this controller uses a battery and also provides power outputs.

 

The controller itself is 129 Baht https://www.lazada.co.th/products/pwm-30a-solar-charge-controller-12v-24v-lcd-display-dual-usb-solar-panel-charger-i298448297-s511734598.html

 

Is the breaker etc and putting it on a board worth 1000 Baht to you?

 

[mixed]

30 minutes ago, Crossy said:

 

The controller itself is 129 Baht https://www.lazada.co.th/products/pwm-30a-solar-charge-controller-12v-24v-lcd-display-dual-usb-solar-panel-charger-i298448297-s511734598.html

 

Is the breaker etc and putting it on a board worth 1000 Baht to you?

 

Looks like the same unit can be had for B1,000. If an extra B800 would mean I don't have to keep researching, that the controller won't smoke and also gives me two power points then it would be. I could charge my 36v Bosch tool batteries from the powerpoints. There are similar systems that also have an inverter, this is something I could add later.

[snowgard]

What is the pipe size of your deep well? It must be big enough that the submersible water pump fit.

Sometime the builders used a small 2" pipes for it but the most pumps need 4".

[Elkski]

I think the charge  controllers are usually separate from inverters.   An inverter is a whole next  level.  Here is a good resource explaining the physics and math behind lifting  water.   Some nice math examples in the how the numbers are calculated PDF link.   

 

https://codegreenprep.com/2012/05/the-energy-cost-of-pumping-water-from-a-well/

You still haven't told us if your current pump is at the surface or submersible.   Or it's voltage or rating.    If you have a pump and an amp meter or watt meter you can measure your system loses currently.  Measure  the power used to pump a measured amount of water.   

Here is another good read and only 6 months old. https://offgridpermaculture.com/Water_Systems/How_to_Run_a_Well_Pump_on_Solar.html

[mixed]

Thanks for the replies, I've been dealing with some family matters over the last few days.

Quote

You still haven't told us if your current pump is at the surface or submersible.   Or it's voltage or rating.    If you have a pump and an amp meter or watt meter you can measure your system loses currently.

At present I don't have a pump to the well. I would prefer surface, however I think for a well it a submersible is recommended, but I'm not sure. I'm not trying to have the most efficient system, I'm looking for a simple system at a reasonable cost, that can be added to later.

 

So far this is what I'm considering, any feedback is much appreciated.

SOLAR PANEL

This one is considerably cheaper than any others, however it has no reviews as yet, although the brand does have a good looking website.

 

SUBMERSIBLE PUMP

This seems to be the best value, with plenty of good reviews, although I think it's more than I need (I haven't found anything smaller with decent reviews).

 

SURFACE PUMP

If I can get away with a surface pump, this one has good reviews, is a good size with a reasonable price.

 

VOLTAGE CONTROLLER

This one looks like good value.

 

Is it correct that this is all I'll need and it can be installed fairly easily? Any feedback is much appreciated. Thanks

 

[Crossy]

26 minutes ago, mixed said:

Is it correct that this is all I'll need and it can be installed fairly easily? Any feedback is much appreciated. Thank

 

You'll need a battery to use that charge controller, but the submersible pump suggests that you can run it directly off one 250W (or bigger) panel.

 

 

 

[mixed]

Thanks for the fast reply Crossy, that's very helpful. Do all the charge controller's need batteries?

 

[Crossy]

18 minutes ago, mixed said:

Do all the charge controller's need batteries?

 

No, but many will emit the Magic-Smoke if they don't have one. Best to talk to the supplier if you want one that will work battery-less.

[mixed]

Does the panel need to be receiving direct sun without clouds to produce 300w? I prefer the surface pump because it's a lower wattage, will this mean it would be more likely to work on overcast days than the 250w pump? Thanks.