--- title: "Understanding Eskom Demand Charges — and How Solar & BESS Reduce Them — SOLINK" description: "For most C&I businesses, demand charges are 30–40% of the electricity bill and don't reduce with solar alone. Here's how demand charges work, why battery storage matters, and where the real savings live." lang: en json-ld: --- [![SOLINK](/assets/solink-logo-DvjvhsCl.png)](/) [Home](/)[About](/about) [Services](/services) [Industries](/industries) [Projects](/projects)[The Group](/group) Platforms [Resources](/resource-hub)[Careers](/careers) [Get in touch](/contact) [← Back to Resource Hub](/resource-hub) # Understanding Eskom Demand Charges — and How Solar & BESS Reduce Them 10 July 2026 · SOLINK ![Understanding Eskom Demand Charges — and How Solar & BESS Reduce Them](/__l5e/assets-v1/d9849584-7d73-4c2c-873b-f935f26bbd56/solink-solar-panel-battery-storage-system-south-africa.jpg) Most South African businesses evaluating solar focus on the R/kWh energy tariff. That is the wrong number to obsess over. For any commercial or industrial site on a demand-based Eskom tariff — Megaflex, Miniflex, Ruraflex or the equivalent municipal tariff — the demand charge is 30 to 40% of the total electricity bill. And here is the uncomfortable truth: solar PV, on its own, barely touches it. Understanding why is the difference between a solar project that delivers on its business case and one that quietly underperforms for 20 years. ## **What a Demand Charge Actually Is** A demand charge is levied on your peak kilowatt draw during a defined billing period — not on the total kilowatt-hours you consume. In simple terms: your energy charge pays for how much you use; your demand charge pays for how big your instantaneous appetite is. Eskom's demand charges are further split into a Network Access Charge (fixed on notified maximum demand) and a peak demand charge (variable on the highest half-hourly kW measured during peak periods). This means a factory that runs one large press for 15 minutes at 2 pm can generate a demand charge as high as a facility that runs steadily at half the load all month. ## **Why Solar Alone Doesn't Fix It** Solar PV reduces your kWh consumption during daylight hours. That directly cuts the energy component of the bill. But your peak demand — the moment your load is highest — often occurs at the start of a shift, during a heavy machinery start-up, or in the evening after solar has stopped generating. If those peaks remain, the demand charge remains. Some businesses see their solar bill savings undercut by demand charges that barely moved. ## **How BESS Changes the Equation** This is where a correctly sized Battery Energy Storage System (BESS) transforms the business case. A BESS can discharge precisely during your peak windows — shaving the top off your demand curve. Instead of your peak coming from the grid, it comes from the battery. This is called peak shaving, and for many South African C&I sites it delivers a larger financial saving than the solar energy production itself. ### A Simple Illustration Consider a mid-size factory with a monthly Eskom bill of R1.2 million. Energy charges make up R750,000, demand charges R400,000 and fixed charges R50,000. A rooftop solar system that delivers 30% of annual consumption might reduce the energy bill by R220,000/month — but leaves demand charges nearly untouched. Add a right-sized BESS optimised for peak shaving, and the demand charge can drop by another R120,000 to R160,000/month. On a 10-year view, the incremental IRR of adding storage is often higher than the base solar IRR. ## **The Three Numbers That Determine BESS ROI** - Your demand tariff (R/kVA or R/kW) — the higher, the better BESS pays back. - The shape of your peak demand — sharp, short peaks are BESS's sweet spot; long, flat peaks are less economic. - The time-of-use structure — Megaflex peak/standard/off-peak differentials drive arbitrage opportunities. ## **Where to Start** SOLINK begins every BESS assessment with an analysis of your last 12 months of half-hourly consumption data and your current tariff structure. From that we can model — precisely and independently — whether solar-only, BESS-only or an integrated solution delivers the strongest returns for your specific site. Get in touch to run the numbers on your facility. Keep reading ## Related articles [View all →](/resource-hub) [ ![Eskom Tariff Increase 2026 — What It Means for Commercial & Industrial Businesses](/__l5e/assets-v1/9b12d9c1-3919-4132-a616-e32ebf28ac32/solink-traditional-electricity-rising-energy-costs-south-africa.jpg) 10 July 2026 ### Eskom Tariff Increase 2026 — What It Means for Commercial & Industrial Businesses NERSA's 2026 tariff decision has landed. Here's what changed, what it means for C&I electricity bills through the year, and which businesses are most exposed. ](/resource-hub/eskom-tariff-increase-2026-what-it-means-for-ci)[ ![Solar PPAs Explained — What South African Businesses Need to Know](/__l5e/assets-v1/9ece5a00-c805-4f07-9671-2b0c64dd04c8/solar-panel-side.jpg) 10 July 2026 ### Solar PPAs Explained — What South African Businesses Need to Know A Power Purchase Agreement lets a business consume solar power without owning the system. Here's how PPAs work in South Africa, what the tariff structure looks like, and the five clauses that make or break the deal. ](/resource-hub/solar-ppa-explained-for-south-african-businesses)[ ![Volatile Electricity Costs Are Hurting Your Bottom Line — Here's How Businesses Are Locking In Savings](/__l5e/assets-v1/1114c4e3-c1a2-4bfb-b75b-986798c0b0cb/solink-business-owner-stressed-rising-electricity-costs-south-africa.jpg) 8 May 2026 ### Volatile Electricity Costs Are Hurting Your Bottom Line — Here's How Businesses Are Locking In Savings ](/resource-hub/volatile-electricity-costs-are-hurting-your-bottom-line-heres-how-businesses-are-locking-in-savings) Newsletter ## Renewable energy insights, straight to your inbox Independent commentary on solar, BESS, wheeled energy and the South African electricity market. Subscribe I agree to receive marketing communications from SOLINK. You can unsubscribe at any time. SOLINK South Africa's independent renewable energy consultant, project developer and facilitator — engineering bankable solar, BESS and wheeled energy solutions for commercial and industrial businesses. [Start a project](/contact) Services - [Overview](/services) - [Feasibility Studies](/services/feasibility-analysis) - [Battery Storage](/services/battery-storage) - [Wheeled Energy](/services/wheeled-energy) - [Glint & Glare](/services/glint-and-glare) Company - [About](/about) - [The SOLINK Group](/group) - [Projects](/projects) - [Careers](/careers) - [Contact](/contact) - [LinkedIn](https://www.linkedin.com/company/solink-power-procurement/) - [Resource Hub](/resource-hub) Platforms - [SOLINK Procurement](https://www.solinkplatform.co.za/login/) - [SOLTRAK](https://app.soltrak.co.za/) - [SOLINK Core](/core) Contact Cape Town Black River Park, Fir St, Observatory, Cape Town, 7925 [021 300 0485](tel:+27213000485) Johannesburg 3rd Floor, Unit T, 165 West St, Sandown, Sandton, 2031 [010 500 7675](tel:+27105007675) [info@solink.co.za](mailto:info@solink.co.za) © 2026 SOLINK. All rights reserved.· [Privacy Policy](/privacy-policy) Independent renewable energy advisory · South Africa