Hi smart people,

I need some advise please. I would like to run my pool pump off solar, with the grid supply as a backup or to cater for shortfall. I don't want to use batteries. Only solar. Inverter will be connected to the pool pump DB. Herewith my idea:

Existing pump spec:

Speck 1.1kW
Operating Watts: 1085w (Tested)
Start-up watts: 1630w (Tested)

Proposed Inverter: Growatt 3000w. Max PV array 1500w. Max open circuit voltage: 102VDC. MPPT range@operating voltage: 30-80 VDC.

https://www.solarwaysuppliers.co.za/wp-content/uploads/2014/01/GROWATT-PDF-NEW.pdf

 

I WOULD APPREICATE ADVISE ON AN ALTERNATIVE INVERTER. PRICE RANGE R5000-R8000.

Questions:
 

• I'm thinking of getting 3 x 450 watt panels. Is that enough? What do I need to look out for?
• Can the proposed Growatt inverter operate without batteries connected?
• If the power generated from the panels doesn't meet the full pump load. Can the balance be taken from the grid? 
• I assume the motor start-up can be powered by grid and then switch to solar for operating power?

Any advice would really be appreciated.

Thanks in advance
Delwin

5 hours ago, Delwin said:

Hi smart people,

I need some advise please. I would like to run my pool pump off solar, with the grid supply as a backup or to cater for shortfall. I don't want to use batteries. Only solar. Inverter will be connected to the pool pump DB. Herewith my idea:

Existing pump spec:

Speck 1.1kW
Operating Watts: 1085w (Tested)
Start-up watts: 1630w (Tested)

Proposed Inverter: Growatt 3000w. Max PV array 1500w. Max open circuit voltage: 102VDC. MPPT range@operating voltage: 30-80 VDC.

https://www.solarwaysuppliers.co.za/wp-content/uploads/2014/01/GROWATT-PDF-NEW.pdf

 

I WOULD APPREICATE ADVISE ON AN ALTERNATIVE INVERTER. PRICE RANGE R5000-R8000.

Questions:
 

• I'm thinking of getting 3 x 450 watt panels. Is that enough? What do I need to look out for?
• Can the proposed Growatt inverter operate without batteries connected?
• If the power generated from the panels doesn't meet the full pump load. Can the balance be taken from the grid? 
• I assume the motor start-up can be powered by grid and then switch to solar for operating power?

Any advice would really be appreciated.

Thanks in advance
Delwin

I don't know this inverter apart from looking at the specs. To me this is not what you need. This charges battery from PV and AC.

You need a grid tied inverter like the Solis 4G mini or the newer replacement model.

Okay thank you. I would like to use without the battery yes.

Then this one then: https://ecopec.co.za/product/solis-mini-4g-single-tracker-inverter-2-0kw/?utm_source=googleshopping&utm_medium=shp&utm_network=x&utm_mobile=0&utm_creative=&utm_position=&utm_random=759919814526010837&gclid=Cj0KCQjwhsmaBhCvARIsAIbEbH5Pcr_ivOAW8Q4WQZoqMlDbXcSv9WEHvIhiQp8ZUt0pmL_N3CFrEdsaAqjQEALw_wcB&utm_campaign=smart shopping - za (3)&utm_ad_group_id=984757&utm_campaign_id=1025688&utm_prod_id=5628

 

 

have you looked at this option from speck?

https://www.speck-pumps.co.za/badu-solar-system/

I have no experience with either inverter.

What I understand is that you want an "out" on the inverter to the pump, and an "in" on the inverter from the grid and PV.  Pump starts and runs and as the PV ramps up the kw produced by PV reduces the draw from the grid.  The inverter should be able to blend the grid and solar PV to meet the pump requirements.  That way you reduce your cost of grid power. 

Technically a grid tie inverter does just that ...

 

@JayN Yes, exactly that. Thank you. 

@liceman Yes, they are rather expensive. Around 20K. I think my idea would cost less + I don't have to change my pump. 

My understanding is that a grid-tied inverter will not work if there is no grid supply. Not a biggy. 

Will a hybrid inverter work? 

9 hours ago, Delwin said:

Okay thank you. I would like to use without the battery yes.

Then this one then: https://ecopec.co.za/product/solis-mini-4g-single-tracker-inverter-2-0kw/?utm_source=googleshopping&utm_medium=shp&utm_network=x&utm_mobile=0&utm_creative=&utm_position=&utm_random=759919814526010837&gclid=Cj0KCQjwhsmaBhCvARIsAIbEbH5Pcr_ivOAW8Q4WQZoqMlDbXcSv9WEHvIhiQp8ZUt0pmL_N3CFrEdsaAqjQEALw_wcB&utm_campaign=smart shopping - za (3)&utm_ad_group_id=984757&utm_campaign_id=1025688&utm_prod_id=5628

 

 

Yes this is the easy solution as long as you don't use some prepaid meters that might trip. The inverter is slow to throttle although it does use a CT to prevent export.

The true hybrid can do the same but also has the back up or normally called essential side.

The Solis does not have a input and output as is normally assumed. It only has a input from the main DB. This very same 3 wires are used to put the power generated by the MPPT from the panels on top of the grid. This power is always used before any grid and if it is not enough for the load the remaining power is seemless drawn from the grid.

The Solis 4G mini from 0.7kW up to 2.5kW can work with 2 panels with a starting volts of 60 and after start on 50V. Normally 60 cell panels will provide enough volts to start and work during the day.

If you need to control the output one can use say a 2.5kW and only fit panels to 500W and then the output will be capped at what these 500W panels provide.

Simple install as you just need the 3 wires to the main DB through MCB to the main 220V. Plus the 2 wires from the PV string which can be up to about 500V. No noise from fans. Only a few clicks in the morning from relays as it synch with the grid. Cannot trip. Even if more panels are fitted than the maximum it will just cap its output to the size of the inverter.

@Scorp007 Thank you for this. 

On 2022/10/27 at 5:31 PM, Delwin said:

@Scorp007 Thank you for this. 

Delwin, did you install this system? If so what did you use as I am currently looking at the same issue.  
rgds Rob 

On 2022/10/21 at 9:07 AM, Delwin said:

Okay thank you. I would like to use without the battery yes.

Then this one then: https://ecopec.co.za/product/solis-mini-4g-single-tracker-inverter-2-0kw/?utm_source=googleshopping&utm_medium=shp&utm_network=x&utm_mobile=0&utm_creative=&utm_position=&utm_random=759919814526010837&gclid=Cj0KCQjwhsmaBhCvARIsAIbEbH5Pcr_ivOAW8Q4WQZoqMlDbXcSv9WEHvIhiQp8ZUt0pmL_N3CFrEdsaAqjQEALw_wcB&utm_campaign=smart shopping - za (3)&utm_ad_group_id=984757&utm_campaign_id=1025688&utm_prod_id=5628

 

 

I hope that you did not buy from Ecopec.  They ripped me off.  I paid for a purchase.  They did not have the product.  Paid me a portion back and kept R12000.