🌾 Planning Estimates for 2026 ⚡ Free & Instant

Off-Grid Farm Solar Calculator South Africa

Size your system by farm type — house, borehole, cold storage or full operation. Compare it against Eskom's real fixed connection costs before you decide. Updated 2026.

Step 1 of 5
What's the primary use of your farm?
This sets a starting load profile — you can fine-tune every appliance in Step 3.

Recommended System

Array Size

Battery Bank

Complete battery sizing guide →

Cost Breakdown

Inverter Recommendation

MPPT charge controller + hybrid inverter sized to your array

Your 10-Year Cost Comparison — Grid vs Off-Grid

☀️ Off-Grid Farm Advantage

  • Unaffected by Eskom load shedding stages ✅
  • Borehole pump works regardless of grid status ✅
  • Cold storage protected from spoilage risk ✅
  • Security systems always powered ✅

Cost by System Size — Where You Fit

Smart Warnings & Optimization Alerts

The #1 Thing Farm Calculators Miss

The hidden cost of staying connected: Eskom's fixed charges explained

Most farm solar research starts and ends with a usage question: "how many kWh do I use, and what does solar cost to replace that?" For a suburban home, that framing is close enough. For a farm — especially one with a remote dwelling, an isolated borehole, or an outbuilding some distance from the main connection — it misses the bigger number entirely: the fixed cost of simply being connected to the grid at all.

A typical Ruraflex-style farm connection in the 25–30 kVA range carries several fixed components regardless of how much power you actually draw: a service charge, an admin charge, a network capacity charge tied to your connection size, a demand charge based on your maximum draw, and — newer from 2025 onward — a generation capacity charge. Added together, these commonly land in the region of R5,000–R7,000 a month. That is R60,000–R85,000 a year before a single kWh has been used.

The trend is moving in one direction. The service portion of Eskom bills has been shifting from roughly a third of the total bill toward around two-thirds over a three-year period, which means using less electricity does not necessarily bring a proportional drop in what you pay. For a remote borehole, an isolated dwelling, or a distant outbuilding, the honest question worth asking is simple: are you paying R70,000 a year just for the option of grid power you barely use? If the answer is yes, off-grid solar is very likely to cost less over any horizon beyond about five years — and the calculator above builds this comparison into your results automatically.

Water & Irrigation

Direct-drive solar pump vs battery-backed: which for your borehole?

Once a farm decides to solarise its borehole, the next real decision isn't panel brand or inverter size — it's whether to run the pump directly off solar panels into a storage tank, or to route power through a battery bank so the pump can run on demand at any hour. The two approaches suit different situations, and getting this choice right has a bigger effect on total cost than almost anything else in the system.

Option A — Direct-Drive Solar Pump

  • Panels power the pump directly during sun hours, filling a storage tank
  • Cheaper — no battery cost in the pumping circuit
  • Simpler, with fewer components to maintain
  • Longer lifespan — no battery degradation to plan around
  • Limitation: only pumps during sunny hours, so tank capacity matters
Best for: most farm boreholes, where a properly sized tank absorbs the "no pumping at night" limitation.

Option B — Battery-Backed Pump

  • A battery stores energy so the pump can run any time, day or night
  • No dependence on storage tank size
  • More expensive due to the added battery cost
  • More components mean more to maintain
  • Battery capacity degrades over roughly 5–10 years
Best for: continuous-demand applications like dairy operations or high-volume irrigation.

For roughly 90% of farm boreholes

Direct-drive plus an adequately sized tank is the smarter investment — it avoids paying for battery capacity that a tank can provide for a fraction of the cost. Use Step 4 of the calculator to size your tank and pump together.

Scope Clarity

What this calculator can — and can't — size

⚠️ Centre-Pivot Irrigation Reality

  • Large centre-pivot systems typically draw 5,000W–50,000W or more
  • This requires commercial-scale solar design — often 100kW–500kW arrays for full coverage
  • That sits beyond DIY or standard calculator scope
  • Consult a specialist agricultural solar installer for centre-pivot systems above roughly 10HP

Centre-pivot and drip irrigation tend to run hardest during daylight hours — which happens to be exactly when solar produces the most. That overlap means even a partial solar contribution can offset a meaningful share of a season's pumping cost, but full commercial coverage for a centre-pivot system is a different engineering exercise from sizing a farmhouse or borehole system, and it deserves a dedicated design from a specialist rather than a planning-level calculator.

Decision Framework

Grid vs off-grid: how to actually decide

The right answer depends less on ideology and more on three questions: how far are you from an existing connection, how large are your fixed charges likely to be, and how much does downtime actually cost you? A farmhouse a few metres from an existing pole with light usage may do fine staying grid-connected. A remote borehole, an isolated cold room, or a new outbuilding some distance from the network is where the maths tends to swing hard toward off-grid, because you avoid both the connection installation cost and the ongoing fixed charges entirely.

Hybrid systems sit in between: for farms that are already grid-connected and simply want backup against load shedding or supply interruptions, keeping the grid connection while adding solar and a moderate battery bank is often more cost-effective than a full off-grid rebuild. Use your answer in Step 2 of the calculator above — it changes which comparison numbers we show you.

A rough rule of thumb

If a new grid connection or ongoing fixed charges would exceed roughly 60–70% of what an equivalent off-grid system costs over 10 years, off-grid is very likely the better long-term investment — even before counting the load shedding resilience it also buys you.

Reference Table

Farm solar sizing by operation type

Planning-level ranges — your calculator result above will be more specific to your actual loads.

Farm TypeSystem SizeKey LoadsEst. Cost (2026)
Farmhouse only3–8kWHousehold basicsR80,000–R150,000
+ Borehole pump8–15kW+ Water pumpingR150,000–R250,000
+ Cold storage15–30kW+ RefrigerationR250,000–R420,000
Dairy operation20–40kW+ Milking, cleaningR320,000–R600,000
Game lodge15–40kW+ Guest amenitiesR250,000–R600,000
Full commercial50kW+EverythingCustom quote needed
Eco-Tourism

Why game lodges choose off-grid solar (beyond cost)

Running grid cable into a wildlife area is expensive, ecologically disruptive, and works against the exact experience guests are paying for. That's before counting the practical case: remote locations make grid extension costly, and reliability becomes critical the moment guest comfort is on the line.

There's an aesthetic and experiential argument too. No power lines cutting across a wilderness view. No generator noise breaking the quiet during a sundowner. A well-designed off-grid system can power everything from refrigeration and lighting to air conditioning and water pumps — silently, without visual or audio disruption to the guest experience, and in a way that aligns naturally with an eco-tourism brand.

Avoid These

5 mistakes farm owners make when going off-grid

1. Undersizing for seasonal peaks
Irrigation season creates load spikes that an "average day" calculation misses — size for your peak season, not your annual average.
2. No storage tank with a direct-drive pump
A direct-drive pump only works in sunlight — without adequate tank storage, the farm runs dry overnight or on cloudy days.
3. Ignoring three-phase requirements
Larger irrigation pumps and motors often need a three-phase design — a standard residential-only installer may not be equipped for this.
4. Not comparing against fixed grid charges
Many farms could save money by going off-grid but never actually calculate what the grid connection costs long-term — see the Eskom fixed-fee section above.
5. Battery-backing everything unnecessarily
Direct-drive plus a storage tank is often cheaper than a battery bank for pump-only applications — save the battery budget for loads that genuinely need power after dark.
By Location

Planning-level sun hours by South African province

These are broad planning averages, not a substitute for a site-specific assessment — shading, altitude and season all shift the real number.

Tax Considerations

Section 12B and registered farming businesses

Registered farming businesses may qualify for accelerated depreciation allowances on renewable energy equipment under South African tax law, which can materially improve the payback picture calculated above. Exact eligibility and the applicable rate depend on your business structure and the equipment installed, so this is worth confirming with a registered tax practitioner or accountant rather than relying on a general planning estimate — but it's a real factor to bring into the conversation before finalising a system size.

Related Tools

More calculators for your property

FAQ

Frequently asked questions

How big a solar system do I need for a farm with a borehole pump in South Africa?
A farmhouse with a single borehole pump typically needs an 8kW–15kW off-grid system, depending on borehole depth, pump size and household load. Adding cold storage usually pushes this to 15kW–30kW. Run your specific loads through the calculator above for a tighter estimate.
Is it cheaper to go off-grid or stay connected to Eskom for a remote farm?
Often, yes. Ruraflex-type fixed charges commonly run R5,000–R7,000 a month before any usage, which can total R600,000–R840,000 over 10 years. A comparable off-grid system can land in the R210,000–R330,000 range over the same period — though every farm's numbers differ, which is why Step 2 of the calculator builds this comparison for your situation.
Do I need a battery for a solar borehole pump, or can I use direct-drive?
Most farm boreholes are better served by a direct-drive pump feeding a storage tank rather than a battery-backed system — it's cheaper, simpler, and avoids battery degradation, provided the tank is sized to cover overnight demand. See the direct-drive vs battery guide above.
How much do Eskom's fixed charges cost for a farm connection in 2026?
A typical Ruraflex connection in the 25–30kVA range carries fixed monthly charges of roughly R5,000–R7,000 before any electricity is used. These are planning-level figures, not a quoted tariff — confirm exact charges with your local municipality or Eskom directly.
What size solar system does a farm need with cold storage?
A farm running a walk-in cold room or packhouse equipment on top of household and borehole loads typically needs a 15kW–30kW system, scaling toward 30kW–50kW for larger processing operations.
Can off-grid solar power a centre-pivot irrigation system?
Small centre-pivot or large drip systems above roughly 10HP move into commercial-scale territory — often 100kW–500kW arrays — which is beyond this calculator's scope and needs a specialist agricultural solar installer.
How long does a solar borehole pump system take to pay back?
Dedicated direct-drive systems commonly pay back against diesel pumping or grid fees in roughly 18–36 months, though this varies with fuel prices, depth and daily water demand.
Do game lodges and eco-tourism properties benefit from off-grid solar?
Yes. Beyond avoiding expensive grid extension into remote wildlife areas, off-grid solar removes generator noise and power-line visibility, supporting the guest experience eco-tourism properties are built around.