solar-well-pumps-aussie-off-grid-reality-check

By Dave Miller · off-grid sparky · 22 years wiring solar, batteries and sheds in central QLD

“After frying a $1,200 pump on a dry-run in 2019, I now insist on a 24-hour battery buffer for every Aussie solar well.”

OffGrid Masterplan

— Dave. Measure twice, buy once.

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Solar Well Pumps: Submersible vs Surface for Aussie Off-Grid

Stop wasting money on the wrong pump. You need to know this before you buy.

Comparison of submersible and surface solar well pumps with shared panel-driven setup and tank storage.

Submersible vs Surface: The Real Deal

Submersible (pump in the well):

Best for wells deeper than 10m. If your water's below 10m, you're screwed with surface.
No priming needed. Just drop it in and go.
Quieter. You won't hear it whining at 3am.
Price: $1,200–$3,500 (Aussie brands). Don't buy cheap Chinese ones – they die in 6 months.
Downside: If it fails, you're pulling the whole pump out of the well. Costly.

Surface (pump above ground):

Only for shallow wells (max 7–8m depth). If your well's deeper, forget it.
Cheaper upfront ($500–$1,500) and easy to fix.
Needs priming. If the well runs dry, you burn the pump. Happens every summer.
Only use if you have a reliable water table. Not for dry areas.

Biggest Aussie mistake: Buying a surface pump for a 12m well. It'll sit there doing nothing. You'll waste $1,000 and 3 months of frustration.

Head Calculation: Don't Guess, Calculate

Head = Vertical lift (m) + Friction loss (m). You need this number to pick the right pump.

Example: Your well is 8m deep. You need to lift water 2m to the tank. Total vertical lift = 10m.

Friction loss: For 20mm pipe, every 10m adds ~1.5m head. If you have 15m of pipe, that's +2.25m.

Total head = 10m + 2.25m = 12.25m

Buy a pump rated for AT LEAST 13m head. If it's rated 12m, you'll get 30% less flow.

Use the Solar Water Pumps head calculator (free, Aussie-made). Don't eyeball it.

Practical Tips: What They Won't Tell You

Don't run the pump dry. Install a low-water cut-off. $50. Worth it.
Size your solar array right. A 100W panel runs a tiny pump. For a 10m head, you need 200–300W. Get a solar controller (like the Renogy 12V) to prevent battery drain.
Test the pump before you bury it. Run it for 24 hours on a test rig. If it fails, you're not stuck in a hole.
Check your water table. If it drops below 10m in summer (like in NSW or QLD), get a submersible. Surface pumps will die.
Always get a spare pump. They break. It's not a matter of if, but when.

Australian Suppliers & Pricing (indicative prices)

Solar Water Pumps (solarwaterpumps.com.au)

Best for submersibles. Reliable, Aussie-owned. No fluff.

Submersible: $1,250–$3,200 (for 10–20m head). Includes controller.

Surface: $550–$1,100 (for shallow wells only).

Aussie Solar (aussiesolar.com.au)

Good for budget surface pumps. Check their "off-grid water" section.

Surface: $480–$950. Submersible: $1,000–$2,800.

Warning: Their cheaper submersibles fail. Stick to the $1,500+ models.

Power Solutions (powersolutions.com.au)

For big jobs. They do custom setups.

Submersible: $2,000–$4,000 (for 20m+ head). Includes installation quote.

Get a quote. Don't buy off the shelf for deep wells.

Price reality: $500 surface pump = $1,000 headache later. $1,500 submersible = 5 years of water. Do the math.

The Bottom Line

Submersible for wells deeper than 10m. Surface only if your well is shallow AND you have a reliable water table. Calculate head. Buy for the worst-case scenario (summer drought). Get a spare pump. Use Aussie suppliers – no Chinese junk. If you skip this, you'll be buying another pump in 6 months. Simple.

Worth a watch: How Do I Choose A Solar Pump? · RPS Solar Pumps

It cuts through the sales fluff and spells out the head, flow and voltage specs you need to match your bore, so you can pick the right pump without guessing. — Dave Miller

When to Call a Professional

While many off-grid projects are achievable as DIY, certain situations require licensed professionals:

Electrical work beyond basic 12V DC additions — requires a licensed electrician
Structural modifications to buildings or load-bearing elements
Gas line installation or modification
Solar array installations above safe voltage thresholds
Any work that affects the structural integrity of your property

Always check local regulations and obtain necessary permits before commencing work.