Solar energy is widely regarded as a clean and sustainable power solution. Although some people mistakenly believe that solar panels only function under direct sunlight—or even that they don’t work at all at night—this is a common misconception.

While it is often associated with bright sunshine and arid climates, solar panels can also perform effectively under cloudy weather conditions. Contrary to popular belief, photovoltaic systems continue generating electricity when skies are overcast or during rainy seasons. Thanks to modern solar technology and smart system design, solar power remains reliable and efficient in a wide range of environments, including regions with frequent cloud cover.

HOW does it work?

Modern photovoltaic (PV) panels work by converting sunlight into electricity using photons. Even when sunlight is diffused by clouds, enough light reaches the Earth’s surface to allow solar panels to operate. On a fully overcast day, solar panels can still produce approximately 10% to 25% of their rated output. On partially cloudy days, that range increases to 30%- 60%, depending on the solar panel technology, cloud density, and system setup. Additionally, cooler temperatures under cloud cover can actually enhance solar panel efficiency, since excessive heat reduces output.

Rain, rather than being an obstacle, can actually improve solar panel performance by naturally cleaning the surface of the panels. This removes dust, pollen, and debris that typically accumulate and reduce efficiency. Especially in rural or off-grid installations, this “self-cleaning” effect helps lower maintenance costs and ensures consistent energy production.

In East Africa, off-grid solar solutions are transforming access to electricity in remote and underserved areas. Countries like Kenya and Rwanda have launched large-scale initiatives to deploy solar mini-grids and home systems, especially in regions beyond the reach of traditional power infrastructure. Despite experiencing seasonal rainfall and overcast skies, these systems continue to perform well year-round. Kenya’s Off-Grid Solar Access Project (KOSAP), supported by international agencies, aims to deliver over 250,000 stand-alone solar systems and 120 solar mini-grids across 14 counties. 

Do Solar Panels Function During Hail and Snow?

Solar panels are capable of operating during hail and snowy conditions, although their efficiency may decrease. Much like on overcast days, sunlight can still pass through light layers of hail or snow, allowing the panels to continue producing electricity—albeit at a reduced output.

That said, snow can present specific challenges. If snow accumulates heavily and isn’t cleared, it can cover the surface of the panels and significantly block sunlight. In such cases, energy production may drop dramatically or stop altogether, as the panels are unable to absorb sufficient sunlight.

Tech That Maximizes Performance in Low-Light Conditions

Solar technology has advanced significantly in recent years, making systems more effective even in challenging climates. Here are some key innovations:

  • Monocrystalline solar panels: These are more efficient than polycrystalline ones and perform better in low-light situations.
  • Bifacial panels: Capture sunlight from both the front and rear surfaces, increasing total energy yield, especially with ground reflection (albedo effect).
  • Microinverters: Improve system performance by optimizing power output at the individual panel level, particularly helpful when parts of the system are shaded.
  • Battery storage systems: Allow excess energy generated during sunny hours to be stored and used when sunlight is limited.

Another important factor in maintaining consistent solar output during cloudy weather is the use of high-efficiency solar panels, such as monocrystalline and bifacial modules. These panels are more effective at capturing low-intensity light and reflected radiation, even when direct sunlight is unavailable. Microinverters and smart energy management systems further optimize performance by ensuring that each panel operates independently, which is especially valuable during partial shading or variable weather conditions.

To address intermittent sunlight, solar battery storage systems are increasingly integrated into solar installations. These batteries store excess energy generated during peak sunlight hours and release it during low-production periods, such as cloudy days or nighttime. This is particularly valuable in regions with unpredictable weather or limited access to grid power.

In summary, solar panels do work on cloudy days, and their performance continues to improve through advancements in solar technology, system design, and energy storage.  With proper system planning and the right components, solar energy remains a resilient and scalable solution in the global transition to renewable power.

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