Artificial intelligence (AI) is transforming industries and the infrastructure that powers them. The International Energy Agency (IEA) notes that electricity in a modern data centre is mainly used for storage (5%), networking (5%), backup power (minimal but essential) and cooling. Of these, cooling stands out: depending on efficiency, it can account for anywhere from 7% in hyperscale facilities to over 30% in smaller, less-optimised sites, says Dean Wolson, General Manager: Africa, Lenovo Infrastructure.
As AI workloads drive unprecedented power densities – with racks drawing 20-100 kW or more – cooling has shifted from a supporting function to a frontline constraint.
In South Africa and much of Africa, the challenge is magnified by high ambient temperatures, an unstable grid and rapid cloud and AI growth. Although the continent’s per-capita data centre electricity use remains below 1 kWh per person, it is expected to double by 2030 with South Africa leading as a regional hub for hyperscalers and sovereign AI projects.
This is the thermal tipping point: air cooling, once sufficient, can no longer scale to handle the energy intensity of AI’s future, particularly within Africa’s climate and grid context.
Air cooling has reached its limit
Air has long been the default because it is simple and inexpensive at low power densities. But once racks exceed tens of kilowatts, air becomes inefficient. The temperature differential widens, fans and CRAC units consume more power and thermal throttling risks rise.
Industry research shows a decisive shift towards liquid cooling whether direct-to-chip or immersion. Liquids move heat far more efficiently than air, lowering overall power-usage effectiveness (PUE). Air-cooled systems top out around 70 kW per rack due to the physical limits of air’s heat capacity. At the same time, AI processors now exceed 600 W each – five times higher than just a few years ago.
South Africa’s growing footprint
Africa’s data centre footprint is small but expanding fast. The IEA expects electricity use in this segment to double before the end of the decade. South Africa leads the region but faces persistent grid constraints. Coal remains dominant and, despite better stability in 2024-2025, load shedding and peak demand challenges continue. Rising digital demand, heat-intensive cooling loads and a carbon-heavy grid make the cooling issue particularly acute.
High ambient temperatures further reduce air-cooling efficiency. Across sub-Saharan Africa, smaller temperature margins mean cooling systems must work harder, driving up energy costs and risk of throttling. Ember’s 2024-2025 reviews show regional heatwaves already pushing up residential and industrial cooling demand – putting data centres in direct competition for scarce electricity.
Avoiding this thermal crunch requires technology and policy:
- Liquid cooling reduces energy use and enables higher rack densities.
- On-site solar-plus-battery systems can relieve grid pressure and improve resilience.
- Waste-heat reuse can improve overall efficiency where infrastructure allows.
- Regulatory reform – predictable tariffs, faster permitting for on-site generation and demand-response incentives – will attract private investment.
Africa may also adopt a hybrid model, combining smaller edge sites for latency-sensitive services with large liquid-cooled hubs in areas with stronger grids, low-carbon power or cooler climates.
Relying on air cooling while AI workloads intensify would mean:
- Higher operational costs – rising PUEs and declining competitiveness
- Reduced reliability – throttling during heatwaves or grid stress
- Lost opportunity – slower cloud and AI-ecosystem growth
Although Africa’s overall data centre energy use remains modest, its growth trajectory will strain fragile grids within the next decade.
Next steps for South Africa and the region
Policy makers and industry should incentivise pilot liquid-cooled AI hubs, fast-track hybrid power-and-storage approvals, and foster partnerships between operators and utilities to secure firm capacity. Regulators should set clear energy and water benchmarks for new projects to ensure transparency and accountability.
By combining technical innovation with regulatory foresight, Africa’s digital ecosystem can expand sustainably – turning today’s cooling constraint into a catalyst for cleaner, more efficient and more resilient infrastructure.
