We want to purchase a water tank / water pump that runs off Tshwane water installed as a 'closed loop' system so that if we have water outages, we can use this clean water.

Some background to our system:

• 8kw Sunsynk inverter
• 2 x 5 kw Sunsynk batteries
• 12 x 550 solar panels

Questions to the forum:

• Has anybody done this using their solar installation
• Which water pump should we buy as someone noted that it needs a specific water pump
• How much power does it use from the solar / battery installation and will it cause an issue with draining the batteries at night?

Any other suggestion / comments are appreciated.

This can definitely be done,

• We've done this our side and have been happy with the results. For our 6-person household we went with a 0.75kW VSD pump.
• With inverter/Solar installations, it's common practice to get a variable-speed (VSD) pump rather than a conventional pump: while VSD's are pricier, conventional pumps produce a surge on start-up that can be several times the pump's rating (and hence could overload the inverter/battery if the load is otherwise heavy). Likewise, if set correctly, VSD's consume less power in operation since they adjust speed based on pressure demand.
• Peak consumption of our 0.75kW pump is 800W (this is when several taps are on at the same time). With a single (low-flow-head) shower or a single tap switched on, consumption is about 580W.
• For our use, total power consumption on an average day is around 1.5kWh - 1.8kWh when the pump serves the household for the full day.
  • Water in a tank should be cycled every 2 weeks or so; so the pump needs to run even when municipal water is available to achieve this. In our case when municipal water is available, our pump is on a timeswitch that powers it on only during the day; hence at night we continue to use municipal water. This drops daily pump consumption to around 0.5kWh whilst still hitting the cycle-tank-water-every-2-weeks target.

 

Full system details in my signature; but the 5kW Sunsynk Inverter + 5kWh Hubble battery we use has worked well so far during water outages (we're frugal with water when using the tank - which also reduces battery load during load shedding); I'd imagine your larger system would handle this perfectly.

6 minutes ago, JayMardern said:

This can definitely be done,

• We've done this our side and have been happy with the results. For our 6-person household we went with a 0.75kW VSD pump.
• With inverter/Solar installations, it's common practice to get a variable-speed (VSD) pump rather than a conventional pump: while VSD's are pricier, conventional pumps produce a surge on start-up that can be several times the pump's rating (and hence could overload the inverter/battery if the load is otherwise heavy). Likewise, if set correctly, VSD's consume less power in operation since they adjust speed based on pressure demand.
• Peak consumption of our 0.75kW pump is 800W (this is when several taps are on at the same time). With a single (low-flow-head) shower or a single tap switched on, consumption is about 580W.
• For our use, total power consumption on an average day is around 1.5kWh - 1.8kWh when the pump serves the household for the full day.
  • Water in a tank should be cycled every 2 weeks or so; so the pump needs to run even when municipal water is available to achieve this. In our case when municipal water is available, our pump is on a timeswitch that powers it on only during the day; hence at night we continue to use municipal water. This drops daily pump consumption to around 0.5kWh whilst still hitting the cycle-tank-water-every-2-weeks target.

 

Full system details in my signature; but the 5kW Sunsynk Inverter + 5kWh Hubble battery we use has worked well so far during water outages (we're frugal with water when using the tank - which also reduces battery load during load shedding); I'd imagine your larger system would handle this perfectly.

Excellent thanks Jay for the response. 

@vanwyk.za I like the fact that Jay also mentioned water has to be recycled every "2 weeks or so". Just to add on to this, if you can get your water tank cleaned every 3-6months regularly, that'll ensure it remains clean from deposits that sit just below the outflow valve meaning you may not necessarily then need to invest in a water filter for your system and you can drink directly from the water. I've had a 5000litre water tank since 2015 and run off a DAB 0.5hp pump to the whole house and it's been dream without issues, well save for the regular cleaning. All the best.

Looking for advice on a VSD pump? 0.75kw with WiFi and app if possible. 

Nicely priced and good quality.

Secondly how difficult is it to configure these pumps? 

Must an irrigation specialist / plumber configure this? 
 

Edited May 1, 20242 yr by Raiden2912