True cost calculator

What does each way of paying actually cost — once everything is counted?

Sticker price and monthly repayment only tell part of the story. This model also factors in the opportunity cost of the capital you tie up, and the ongoing maintenance and component replacement that comes with owning a system — so cash, bond, loan and subscription can be compared on the same terms.

Your numbers

Drag the sliders — everything below updates live.

R150 000
R3 000 / month

Today's value — same starting point for every route, since it's the same system generating the same power.

10 years
10%

Typical range 8–12% — this grows your saving every year, for every route, since grid electricity keeps getting more expensive.

4%

Usually capped at CPI (~4%) in the contract — grows the premium each year, slower than electricity typically rises.

9%

What your cash could otherwise earn — money market ≈ 8–9%, equities historically higher but riskier.

10.75%

SA prime is 10.5% (Jul 2026) — bonds typically price at prime to prime+1%.

20 years
15%

Set to LookSee's published solar loan rate — adjust for other funders.

5 years
R3 300 / month
1.5% of system cost

Owned systems only — inverter/battery replacement, cleaning, call-outs. Subscription providers typically carry this themselves.

Net monthly position

Your monthly saving, minus what each route costs you.

Cash

Today

+R3 000

By year 10

+R7 781

No repayment — full (escalating) saving is the net benefit

Bond addition

Today

+R1 477

By year 10

+R6 258

R1 523/mo repayment, fixed at signing

Solar loan

Today

R568

By year 10

+R7 781

R3 568/mo repayment, fixed at signing

Subscription

Today

R300

By year 10

+R2 896

R3 300/mo premium today, rising with escalation

Net financial position over time

Where each route stands, year by year.

CashBond additionSolar loanSubscription

A line trending up means that route is, on paper, paying for itself and then some by that year. Two things now compound into these lines: your electricity saving grows every year (grid tariffs keep rising), while bond and loan repayments stay completely flat — so owned routes tend to curve upward faster the longer you hold them, and sharply once the debt is paid off. The subscription premium also escalates, but usually slower than electricity (CPI-capped vs. tariff inflation) — which narrows the gap over time even though it rarely closes it, since you're paying every month for the life of the contract with nothing owned at the end.

Pros & cons

The trade-offs the numbers don't show.

Cash

Pros

  • No interest cost, typically lowest total cost long-term
  • Full ownership from day one, ~3–4% home resale value uplift (Nedbank/Private Property data)
  • No credit approval or monthly obligation

Cons

  • ×Large capital outlay has an opportunity cost
  • ×Full maintenance/replacement cost sits with the owner
  • ×Upgrading later (e.g. a bigger inverter) is costly — it's not just a component swap, it usually means resizing cables and breakers too.
  • ×Thin secondhand market — real listings show systems reselling around 40–50% of comparable new cost even under 2 years old, if sold separately from the home

Bond addition

Pros

  • Usually the cheapest financed route, prices near prime (10.5%)
  • Long amortisation keeps monthly repayment low
  • Preserves savings, no cash drawdown

Cons

  • ×Needs bond headroom or a further-advance application — not guaranteed, can take weeks
  • ×Increases total debt secured against the home
  • ×Long term means early payments are mostly interest on a depreciating asset
  • ×Upgrading later (e.g. a bigger inverter) is costly — it's not just a component swap, it usually means resizing cables and breakers too.

Dedicated solar loan

e.g. LookSee, ~15%

Pros

  • Fast, purpose-built approval, doesn't touch the bond
  • Shorter fixed term (often 3–6 years), debt-free sooner
  • No bond headroom required

Cons

  • ×Highest interest rate of the credit options
  • ×Shorter term means higher monthly repayment for the same capital
  • ×Still leaves maintenance/replacement with the owner
  • ×Upgrading later (e.g. a bigger inverter) is costly — it's not just a component swap, it usually means resizing cables and breakers too.

Subscription / rental

Pros

  • Little to no upfront capital required
  • Easy to upgrade the system size later — no big upfront cost, since you don't own the hardware.
  • Maintenance and component replacement are usually the provider's responsibility (confirm per contract)
  • Predictable fixed monthly cost, avoids the 4–12 week warranty-repair wait falling on the customer
  • Premium escalation is usually capped at CPI (~4%), typically rising slower than grid electricity tariffs (~8–12%) — your saving margin tends to widen over the contract.

Cons

  • ×You never own the system — no resale/home-equity uplift attributable to it, and no 'paid-off' point where the monthly cost drops to zero.
  • ×Usually the most expensive route in total Rand terms over the system's full lifespan
  • ×Dependent on the provider's solvency and contract terms for the duration

Sources: SA prime lending rate 10.5% as at July 2026 (SARB) · Home resale value uplift ~3–4%, Nedbank Retail & Business Banking / Private Property · Secondhand equipment pricing from current South African marketplace listings. Figures are directional, not guarantees.

This tool is for illustration only and is not financial advice. Actual rates, terms, and outcomes depend on your credit profile, chosen provider, and system specification — always get final numbers in writing before committing.