How to Calculate Your Carbon Tax Liability Under the Carbon Tax Act

Understanding the Carbon Tax Framework

South Africa's Carbon Tax Act (Act No. 15 of 2019) levies a tax on greenhouse gas emissions from specified activities. For property managers, the two primary exposure pathways are direct on-site combustion (Scope 1) and indirect exposure through Eskom electricity tariff pass-through (Scope 2). This section will provide a concise overview of the legislative framework, who is liable, and how the tax interacts with the Carbon Budget Allowance system.

Step 1: Identify Your Emission Sources

Before you can calculate liability, you need to map every emission source across your building or portfolio. This section will cover the three categories relevant to commercial property: grid electricity consumption, on-site fossil fuel combustion (diesel generators, gas boilers), and fugitive emissions (refrigerant leaks from HVAC systems). It will explain how to determine which sources fall under the direct carbon tax and which contribute to indirect exposure through utility costs.

Step 2: Calculate Your Carbon Footprint

This section will walk through the conversion of energy consumption data into tonnes of CO₂e using South Africa's official emission factors. It will cover the Eskom grid emission factor (currently 0.92 kg CO₂e/kWh), diesel combustion factors, natural gas factors, and how to handle mixed-fuel portfolios. A reference table of key emission factors will be included.

Energy source	Emission factor	Unit
Eskom grid electricity	0.92	kg CO₂e per kWh
Diesel (generators)	2.68	kg CO₂e per litre
Natural gas	2.02	kg CO₂e per m³
LPG	1.51	kg CO₂e per litre

Step 3: Apply Tax-Free Allowances

The Carbon Tax Act provides several tax-free allowances that reduce the taxable amount. This section will explain each allowance category available under Phase 2: the basic tax-free allowance (60%), the trade exposure allowance, the performance allowance, the carbon budget allowance, and the carbon offset allowance. It will clarify the total cap on combined allowances and how to determine which allowances your property operations can claim.

Step 4: Calculate Your Net Liability

This section will present the complete calculation formula, bringing together the emission quantity, applicable tax rate, and net allowances into a single computation. It will address the distinction between direct carbon tax liability (payable to SARS) and indirect carbon tax cost (embedded in Eskom tariffs), and explain how to account for both in financial planning.

Worked Example: A 10,000 m² Office Building

This section will provide a complete worked example using a typical Johannesburg office building: 10,000 m² GLA, 180 kWh/m²/year grid consumption, a 500 kVA diesel backup generator running 200 hours per year, and gas-fired heating. The example will walk through each step of the calculation, from raw energy data to final Rand liability, showing both the direct and indirect components and the impact of different allowance scenarios.

"Most property managers are surprised when they see the number. The indirect carbon tax cost embedded in your electricity bill is already material — and it's growing every year as allowances fall."

What to Do with the Number

Knowing your liability is the starting point, not the destination. This section will outline how to use your carbon tax calculation to inform capital expenditure decisions (solar PV, LED retrofits, HVAC upgrades), tenant recovery strategies, budget forecasting, and ESG reporting for GRESB, GRI, and investor disclosures. It will also cover how to set a reduction target that translates directly into Rand savings.