Solar Calculator South Africa 2026

Solar in South Africa: savings and resilience

Solar makes exceptional sense in South Africa for two reasons that reinforce each other: electricity from Eskom has become very expensive and keeps rising, and the country has abundant sunshine. On top of that, the memory of years of load-shedding means many households and businesses value the backup that a solar-plus-battery system provides. The result is one of the strongest solar cases anywhere — fast payback on the savings alone, plus resilience as a bonus. This calculator separates those two cases so you can see both clearly.

Tariffs and tax rules change; figures here are dated references to confirm with current Eskom/NERSA schedules and an accountant.

The economic case: solar vs the Eskom tariff

The core saving is stark. Rooftop solar generates electricity at roughly R0.95/kWh averaged over a 25-year system life, against a grid tariff around R3/kWh and climbing — with NERSA-approved increases adding to it year after year (a further double-digit increase applied in 2026). Every unit you generate and use yourself saves the difference, so payback has compressed to under five years for many homes, after which the power is effectively free for decades. And because each Eskom increase widens the gap, solar gets more valuable over time, not less. The savings simply equal your solar units multiplied by the tariff you avoid — a calculation that grows more favourable with every tariff hike.

The resilience case: backup through load-shedding

Load-shedding is currently paused, but the risk of its return remains real as ageing coal plants retire over roughly 2027–2030 and the grid stays tight. A solar-plus-battery system keeps essential loads running through an outage, which for many South Africans is worth as much as the bill savings. Sizing the backup is straightforward: the battery capacity you need is roughly your essential load (in kW) times the hours of a load-shedding block, divided by the battery's usable depth of discharge. The calculator works this out so you can size storage to ride out the stages you're concerned about, rather than over- or under-buying.

Self-consumption and feed-in

As elsewhere, the most valuable use of your solar is to consume it yourself, avoiding the high Eskom tariff. Some municipalities now offer feed-in arrangements for exported surplus, but rates are typically well below the retail tariff and vary widely by municipality, so they're a bonus rather than the basis of the case. Sizing the system to your daytime consumption — and using a battery to push solar into the evening — captures the most value. Where feed-in is available and worthwhile in your municipality, it adds a little on top, but the economics stand firmly on self-consumption savings alone.

Business incentives

For businesses, South Africa has at times offered accelerated or enhanced tax deductions for renewable-energy investment, which can significantly improve the after-tax return on a commercial solar system. These provisions change, so a business should confirm the current rules with an accountant before relying on them — but where available, they shorten payback further on top of the already-strong savings from avoiding high commercial tariffs and keeping operations running through any future load-shedding.

Frequently asked questions

Very much so. Solar generates power at roughly R0.95/kWh versus a grid tariff around R3/kWh and rising, so payback is often under five years, followed by decades of low-cost electricity. Each Eskom increase makes the case stronger. A battery adds backup through any return of load-shedding.

Roughly your essential load in kW times the hours of a load-shedding block, divided by the battery's usable depth of discharge. Backing up only essentials (lights, internet, a few plugs) needs far less than backing up the whole home, so decide what you truly need to keep running.

It's currently paused, but the risk remains as old coal plants retire over roughly 2027–2030 and the grid stays tight. Many South Africans size a battery for resilience precisely because the future is uncertain — the backup is valuable insurance even if outages stay rare.

South Africa has offered accelerated or enhanced tax deductions for renewable-energy investment at various times, which can meaningfully improve a business's after-tax return. These rules change, so confirm the current position with an accountant before relying on them in your calculations.

Usually not necessary. A grid-tied solar system with a battery gives you the savings and the backup through load-shedding while still drawing on the grid when needed, which is cheaper than sizing a fully off-grid system to cover every worst case. Full off-grid suits remote properties without a viable grid connection.