Over the past five years the pairing of solar photovoltaics (PV) with battery-energy-storage systems (BESS) has moved from demonstration projects to being a core pillar of national energy-transition strategies. Fast-falling battery‐pack prices — by 93% since 2010, reaching USD 192/kWh for utility-scale systems in 2024 — have shattered the notion that reliable 24-hour solar power is a niche product.

Today, PV-BESS plants are being procured not as experimental add-ons, but as bankable sources of firm capacity able to displace diesel, defer thermal peaking plant, and hard-wire flexibility into weak grids.

Why adoption keeps accelerating

On the supply side, two forces are resetting the economics of solar + BESS; price compression and scale. Global module prices fell to record lows through 2024 on the back of Chinese overcapacity, with spot modules touching about USD 0.09/Wattsdc in December. Battery pack prices also dropped sharply between 2010 and 2024, while analysts expect further easing as manufacturing scale and cheaper chemistries diffuse. Together, these shifts lower the levelised cost of electricity (LCOE) and make storage-backed solar competitive in more hours and more places, including secondary and weak-grid locations.

Industrial policy and gigafactory capacity have pushed module and battery costs to record lows while catalysing new chemistries (e.g. lithium iron phosphate, sodium-ion) better suited to hot climates. Digitisation, including AI-enabled dispatch optimisation, forecast-driven charge cycles, and predictive maintenance, etc., further lifts utilisation and investor confidence.  

On the demand side, the driver is no longer just resilience, it’s the physics of solar energy. PV output is diurnal and weather-sensitive, creating steep ramps and fast intra-hour swings. Storage flattens those ramps, shifting midday surplus into the evening when demand peaks, and providing operating reserves and fast frequency response. Data centres are adopting grid-interactive uninterruptible power supply (UPS)/BESS to replace or complement diesel, earning grid-service revenue when idle and tightening onsite reliability.  

Electric mobility also adds another layer to the trend. Across Africa and beyond, start-ups now operate solar-powered battery-swap stations in Rwanda and Kenya, each equipped with approximately 37 kilowatts (kW) of rooftop PV and modular lithium packs, to service more than 17 000 e-motorcycles and 18 000 daily swaps.

Indeed, battery swapping avoids the need for large public chargers that industry players fear would stress weak urban grids. Instead, behind-the-meter PV-BESS clusters leverage daytime solar, charge swap batteries off-grid, and feed surplus back to distribution networks, turning a potential strain into a balancing resource.

Solar+BESS progress in emerging markets

Emerging markets now treat hybrid plants as mainstream infrastructure. Rwanda’s USD 187 million Bugesera project (60 MW PV + 60 MWh BESS) will supply the country’s new international airport and inject guaranteed evening capacity into the national grid, setting a template for future utility procurements. In Egypt, the International Finance Corporation is financing a 300 MWh battery for the 500-MW Kom Ombo solar park.

These examples are not your standard small battery packs (typically 0.5-1MW BESS per 5MW installed PV capacity) that only covers the usual day-time intermittency associated with solar PV. These projects confirm that more stakeholders now view storage as integral to large-scale renewables, and that hybrid or storage-ready solar plants are no longer a mere ‘alternative’; they are a viable way to add dispatchable megawatts in many emerging grids.  

Off-grid, mini-grids built on containerised PV-BESS architectures are scaling faster than ever. A World Bank assessment estimates that solar mini-grids could deliver Tier-3 or better electricity to 380 million people in Africa by 2030 at the lowest life-cycle cost, provided hybrid systems remain the default design. Recent deployments in northern Nigeria and coastal Kenya illustrate the point: batteries sized for evening commercial loads have cut diesel back-up hours by  more than 85%, enabling longer shop opening times and powering new agro-processing enterprises.

The scaling up of this technology in emerging markets is not without challenges, however. The persistent ones include:

• The need for lifecycle stewardship. Developing and emerging economies need to put in place end-of-life frameworks for lithium batteries; without recycling mandates and financing, today’s climate solution could become tomorrow’s waste problem.
• Demand for affordable capital. Support in the form of concessional funds (such as those provided by the Energy Transition Accelerator Financing) remain essential until local lenders are comfortable with merchant-revenue storage projects.
• Absence of local value-addition. Import dependence exposes projects to forex volatility; building assembly plants and training technicians can keep more value onshore.
• Lagging regulatory clarity. Clear rules on storage licensing, tariff design, and grid-service remuneration, are pre-conditions for scaling up.

Frontiers in Solar+ BESS

These days, digital optimisation is turning those batteries into living assets. Developers now twin every megawatt-hour with a digital system that analyses, forecasts and dispatches electricity in real time. Such twinned projects can increase revenues by stacking services across energy, capacity and frequency markets while managing degradation in hot climates.  

As suppliers are racing to commercialise long-duration chemistries and second-life electric vehicles batteries to meet the needs of tropical conditions, there is an opportunity to make the technology more bankable and attractive for emerging markets. The above-mentioned trends signal that PV-BESS is ready to play a more essential role in renewable-based power system, as it is no longer just a transitional fix, but can serve as a backbone of a resilient and flexible energy future.