Section 12B / 12BA Solar Tax Allowance — Complete Guide for South African Businesses

For South African businesses considering commercial solar, the single most misunderstood — and most valuable — component of the business case is not the electricity saving. It is the tax deduction. Section 12B of the Income Tax Act has quietly delivered more accelerated depreciation on renewable energy assets than any other South African incentive, and the temporary Section 12BA enhancement made 2023–2025 the most tax-efficient window ever to invest in solar. This guide breaks down how each allowance works, what still applies today, and what a well-structured project looks like from a tax perspective.

What Section 12B Actually Is

Section 12B of the Income Tax Act allows a taxpayer to deduct the cost of certain renewable energy assets — including solar PV, wind, biomass and small hydro — from taxable income. For solar PV systems below 1 MW, the entire capital cost is deductible in the year the asset is brought into use. For larger systems (above 1 MW), the deduction is claimed over three years on a 50/30/20 basis. Section 12B is not a tax credit and it is not a rebate. It is an accelerated capital allowance — meaning the business writes off the full asset value against taxable profit, reducing corporate income tax in the year of commissioning.

For a company on the 27% corporate tax rate, this effectively means SARS funds roughly 27% of the system cost through reduced tax. On a R5 million commercial solar installation under 1 MW, that is R1.35 million of tax relief in year one — before the electricity savings even begin.

What Section 12BA Added — and Why It Mattered

Announced in the 2023 Budget and legislated through the Taxation Laws Amendment Act, Section 12BA was a temporary uplift on 12B that ran for assets brought into use between 1 March 2023 and 28 February 2025. Under 12BA, the deduction was increased to 125% of the asset cost, with no size cap. That meant a business installing a 2 MW solar system could deduct R1.25 for every R1 spent — a 25% tax-driven return before generation had produced a single kilowatt-hour.

12BA was designed to accelerate C&I solar adoption during the worst of load shedding. It succeeded: the two-year window drove record procurement activity. That window has now closed. Assets brought into use from 1 March 2025 onward revert to the standard Section 12B regime.

What Still Applies Today

Section 12B is permanent. For any qualifying solar PV asset commissioned in the current tax year, the 100% year-one deduction (for systems under 1 MW) or the 50/30/20 deduction (for systems above 1 MW) continues to apply. This alone remains one of the most generous capital allowances in South African tax law. The business case for commercial solar has not weakened — the temporary 25% uplift has simply been removed.

What Qualifies

• Solar PV panels, inverters, mounting structures, DC and AC cabling, combiner boxes, and installation labour.
• Grid-tied, hybrid and off-grid configurations, as long as the asset is used in the production of income.
• Systems owned by the taxpayer — assets on a PPA are owned by the funder, so the funder claims 12B, not the offtaker.
• Battery energy storage where it forms part of the renewable energy generation asset (SARS treatment on standalone BESS is more nuanced — get advice).

What Does Not Qualify

Section 12B does not apply to residential systems on personal properties, to leased equipment where the taxpayer is not the owner, or to purely resilience-driven backup infrastructure (generators, standalone UPS). It also does not apply retrospectively — the asset must be brought into use in the year the deduction is claimed.

How SOLINK Helps

Tax structuring is one of the levers that turns a good solar project into a great one. SOLINK works alongside your tax advisor to structure ownership, commissioning timing and asset registers so the full Section 12B benefit is captured — and to compare owned vs PPA vs solar asset refinancing structures on a fully tax-adjusted basis. The right answer depends on your tax position, your capital availability, and your risk appetite. Get the structure wrong and you leave millions on the table.

If you are evaluating a commercial solar project and want an independent view on the tax structuring, get in touch.