• Extreme heat and dust reduce solar panel efficiency by 15% to more than 60% across sub-Saharan Africa.

• Module surface temperatures often exceed 70°C, sharply lowering voltage and energy conversion rates.

• Researchers urge manufacturers to adopt region-specific solar design and maintenance standards.

Solar power generation systems suffer significant efficiency losses across sub-Saharan Africa due to extreme heat and dust accumulation, according to a report published on Sunday, February 1. Researchers from Arusha Technical College and the Nelson Mandela African Institution of Science and Technology in Tanzania released the findings in the scientific journal Discover Sustainability.

The report, titled “Photovoltaic system performance in SubSaharan Africa under environmental, technical and policy constraints,” drew on field analyses conducted across several countries in the region. The study assessed performance losses affecting solar panels operating under local environmental conditions.

High ambient temperatures, intense solar radiation, and humidity accelerate thermal degradation in sub-Saharan Africa. These environmental conditions add thermal stress that directly impairs photovoltaic performance.

In many areas south of the Sahara, daytime conditions frequently push module surface temperatures above 40°C. These levels exceed the temperatures at which photovoltaic systems achieve optimal efficiency. Several studies show that module surface temperatures above 25°C degrade power conversion efficiency. These findings indicate that photovoltaic performance losses begin well before heat reaches extreme levels in sub-Saharan Africa.

At the extreme levels often recorded in the region, module temperatures can exceed 70°C. Such conditions significantly reduce open-circuit voltage and increase recombination losses. Field data confirm that crystalline silicon modules, the most widely used photovoltaic technology, can suffer efficiency losses of 15% to 20% under these thermal stresses. These losses reduce overall energy yields, particularly in off-grid and rural systems where capacity margins already remain limited.

Dust accumulation represents another major constraint on solar performance in sub-Saharan Africa, particularly in arid and semi-arid zones. Unlike desert regions where dust consists mainly of mineral particles, much of the dust in sub-Saharan Africa contains higher proportions of organic matter, moisture-retaining particles, and saline deposits. Without frequent cleaning, these layers block sunlight and sharply reduce electricity production.

Observed output losses range from 20% to more than 60%. Particle size, tilt angle, and humidity all influence the scale of these losses. However, efficiency losses vary widely by environment. Industrial zones characterized by coal dust experience efficiency losses ranging from 53% to 64%. Dust aggregates from construction sites and mining areas cause reductions of between 58% and 72%. By contrast, agricultural areas exposed to organic fertilizer dust record losses of about 25% to 35%.

Developing climate-adapted technologies

The report also highlights persistent maintenance challenges at many rural solar installations. Limited infrastructure and financial resources prevent regular upkeep in remote areas.

To reduce the impact of high temperatures on panel efficiency, researchers examined passive and active cooling techniques, including ventilation systems, heat-dissipating materials, and reflective surface coatings. Passive cooling methods improve performance without additional energy demand. Active cooling systems deliver greater efficiency gains but often require water or electricity, which limits their practicality in isolated regions.

The study also notes that some protective coatings degrade faster than expected in tropical environments, raising long-term costs.

The authors warn that environmental efficiency losses undermine the reliability of one of the region’s most critical clean energy solutions. Nearly 600 million people in sub-Saharan Africa still lack access to electricity. Against this backdrop, the researchers call on industrial solar companies to adopt region-specific standards for panel design, certification, and maintenance.

The report identifies three priorities. Manufacturers should develop photovoltaic components optimized for high-temperature operation. Operators should adapt cleaning protocols to local dust conditions. Regulators should establish certification systems for solar technologies designed for tropical climates.

This article was initially published in French by Walid Kéfi

Adapted in English by Ange J.A de BERRY QUENUM