Battery energy storage systems (BESS) are making headlines for good reason. As renewables become a substantial part of South Africa's energy infrastructure, attention is turning toward energy storage.
Owners of renewable energy systems use batteries to store excess energy. But BESS for storage is more sophisticated than other battery systems, with advantages that boost overall sustainability. They are well-suited for both grid-scale storage and meeting smaller, yet still significant energy demands for industrial, business, and even residential users, says John Taylor, Head of M&A and Large C&I at Yellow Door Energy South Africa.
"The BESS market has expanded significantly, ranging from systems as small as a few kilowatt-hours to massive utility-scale storage. These options have grown as renewable energy markets matured. At first, the focus was on the cost and returns of energy-generation systems, using standard battery storage to plug any gaps. But today, sophisticated storage systems are in more demand because they give system owners more flexibility and control."
Energy storage's meteoric growth
That popularity reveals how much renewable energy has gone from the fringe into a central part of energy sustainability. In 2015, total energy storage investments totalled $1bn. Today, those orders exceed $70bn, according to the International Energy Agency’s World Energy Investment 2025 analysis.
Cheaper lithium-ion batteries spur that growth. Benchmark Mineral Intelligence estimates that Li-ion battery prices have reduced from US$290 in 2014 to $78 per kilowatt-hour. The same report reveals that the market's installed capacity has grown from 168 gigawatt-hours to over 3,400 gigawatt-hours.
While several sectors buy from the energy storage market, battery systems that support renewables have become one of the biggest battery consumers, with BESS taking centre stage. BESS combines batteries with electrical components such as inverters, as well as cooling and management technologies to ensure efficient energy delivery and longer battery lifespans. These additions have made it more economically viable to invest in larger battery storage and expand its versatility.
"The market's attitude used to be that batteries are for emergencies, to literally keep the lights on. Now, more and more companies are using BESS or hybrid energy solutions to reduce their energy costs and risks. It's not an emergency measure but a central part of sustainable and affordable energy," says Taylor.
BESS is becoming crucial for utility-scale operations as part of a Purchasing Power Agreement (PPA) to manage demand and grid frequency. However, industrial, commercial, and residential energy users are also discovering advantages. How are companies using BESS for more value and sustainability? The use cases include:
- Storing cheaply generated energy for use during peak demand periods, aka. peak shaving.
- Managing power fluctuations and voltage sags that damage electrical and industrial equipment.
- Creating energy independence by leaning less on national grid infrastructure and supporting microgrids.
- Provide cheap power for recharging electric vehicles without imposing a limited recharge window.
- Provide high-quality and comprehensive backup power without incurring fuel costs and carbon production, such as when using generators.
- Wheel excess energy for extra revenue.
It's tempting to reduce BESS as a shorthand for larger batteries. But in reality, BESS elevates the sustainability and economics of renewable energy, leading many to say that 2026 will be BESS's year.
"Interest in BESS has been growing for a while and surged in 2025. But 2026 is going to be even bigger," says Taylor. " It's a buyer's market, thanks to lower battery prices, large amounts of inventory, and wider adoption of renewables. The sophistication of energy mixes is also increasing interest. Sites can combine things like solar, wind, hydro, turbines, and even efficient generators. BESS extends the lifespan and value of those systems."
South Africa's energy market keeps growing, and renewables are a major part of that growth, leaping from 3.4 gigawatts in 2015 to 13.5 gigawatts in 2024. This growth has opened more options to owners and users of renewable energy, realising that BESS for storage creates more energy independence than just having power when utility sources fail. BESS is helping the market exercise more of those options, building a future of affordable and sustainable energy.
