Do Solar Panels Need Direct Sunlight

Do solar panels need direct sunlight? Solar panels may be installed in areas that do not receive direct sunlight. This may happen if nearby buildings or trees cast shade over them or they’re positioned such that they face away from the sun.

Solar panels that lack direct sunlight become much less effective at producing electricity since direct sunlight provides ideal conditions for photovoltaic conversion to generate power. When shaded or facing away from the sun, solar panels receive less direct sunlight, leading to lower overall energy production.

Do Solar Panels Need Direct Sunlight?

Solar panels work best when exposed directly to sunlight; however, they still perform at some level even without it.

Solar panels produce electricity by harnessing both direct and indirect sunlight as inputs, using photons from both direct sunlight and diffuse sunlight as sources of power to produce electricity. They can even produce power in the absence of direct sunlight!

However, solar panel performance will deteriorate without direct sunlight. To reach their maximum output of 1000 W/m2, solar panels must receive direct sunlight exposure of at least 15 hours each day in order to achieve their irradiance threshold of 1000W/m2.

Do Solar Panels Work in the Shade?

Solar panels will still work under shaded conditions, but the current they generate will be less than it would have been in optimum conditions.

What factors determine the exact impact of shading on solar power systems?


The longer your solar panels remain shaded, the less electricity they will produce. It is important to note that the amount of sunlight and shade will vary from day to day due to the ever-changing path of the sun.


Modern solar panels equipped with half-cut photovoltaic cells are designed to mitigate the impact of partial shade. However, this is different from standard solar panel technology. Standard solar panels (i.e., those without half-cut cells) are more susceptible to performance degradation in shaded conditions.

Inverter Setup

If you utilize a central string inverter, shading on a single panel will result in reduced power output for the entire solar array. Conversely, when using MLPEs (microinverters or DC power optimizers), shading on one panel does not affect the performance of other panels significantly. It only leads to a slight decrease in energy production. The following information further explains the distinction between string inverters and MLPEs.

Before installing solar panels, it is advisable to assess the extent of shade on your roof. If you anticipate limited or partial shading, opting for solar panels equipped with half-cut cells connected via MLPEs (microinverters or DC power optimizers) can help minimize output losses. However, if your roof experiences significant shading, it may be worth considering whether installing solar panels there is a viable option.

A professional solar installer can accurately determine the amount of shade a specific section of your roof receives throughout the year. They can also assist you in calculating your solar panel output and estimating the solar payback time based on these factors.

Weather Conditions Can Also Impact Sunlight Availability

The weather conditions can affect solar panel production. Clouds, snow, and rain can reduce direct and indirect sun, affecting solar power production.

Do Solar Panels Work on Cloudy Days?

Solar panels are capable of functioning in cloudy weather, although their performance is not as optimal as on sunny days. Clouds hinder a portion of the sun’s energy from reaching the Earth (or, in this context, your roof), resulting in reduced effectiveness.

Under overcast conditions, solar panels can still generate between 10% and 60% more power compared to direct shade. The actual increase in power output depends on the thickness of the cloud cover.

Do Solar Panels Work in the Rain?

Rainfall does not directly impact the output of solar panels, but it is the heavy cloud cover accompanying rain that can have an effect. When rain clouds block sunlight and darken the sky, the output of the solar panel system can decrease by 40-90%.

Interestingly, despite its temporary impact on output, rainwater provides an unexpected advantage by aiding in the cleaning of solar panels. In dusty environments, a substantial downpour can effectively enhance solar output by washing away accumulated dust and debris.

Do Solar Panels Work When It Snows?

Solar panels can generate electricity even in snowy weather, as long as the snowfall is not excessively heavy.

Solar panels can continue producing electricity even with a light layer of snow covering them. Cold weather can benefit solar panels by preventing them from overheating and thereby maintaining their efficiency.

However, if the snow accumulation becomes too heavy, it can reduce the energy output of the panels. Fortunately, solar panels are designed to effectively shed snow, making this occurrence rare. Their smooth surface, heat absorption, and typically inclined installation contribute to the natural snow removal process.

It is worth noting that snow, similar to rain, also serves as a natural cleaning agent for solar panels as it melts, as emphasized by the Department of Energy.

How Much Sunlight Do Solar Panels Require to Be Economic?

A general guideline suggests that a solar energy system is economically viable if it receives a minimum of four hours of peak sunlight each day.

The cumulative solar radiation during these four peak hours amounts to 4000 watts. In this blog, we provide information on peak sun hours and specific values for each state.

However, solar power goes beyond the quantity of sunshine alone. There are additional factors that homeowners need to take into account. When calculating the payback period, it is important to consider local utility rates and state incentives.

Solar energy can lead to greater cost savings in regions with higher utility costs and favorable local incentives. Massachusetts, for example, receives an average of only three peak hours of sunlight per day, but it is still considered one of the most attractive places for solar adoption. In such areas, payback periods can be as low as 3.2 years.

The Bottom Line – Do Solar Panels Need Direct Sunlight?

So, do solar panels need direct sunlight to work? The answer is No! 

While direct sunlight does indeed enhance the efficiency of solar panels, they are not wholly reliant on it. Solar panels can function efficiently even under overcast conditions, generating considerable amounts of electricity. They capture and convert not just the visible light but also the invisible parts of the sunlight spectrum. 

Modern solar technology has advanced to the point that panel orientation, reflectors, and advanced photovoltaic cells have significantly lessened any impact of non-ideal sun conditions on photovoltaic cells. No matter where you reside; be it sunny regions or those prone to cloudy skies; don’t let sunlight stop you from making green energy choices!

Are you seeking greener, sustainable, and cost-effective energy solutions? Consider ESD Solar for assistance. ESD Solar has years of experience bringing solar energy benefits to homes and businesses throughout Florida, Texas, Oklahoma, Colorado, and Ohio. Our cutting-edge solar technology can capture sunlight even under challenging conditions for maximum return on your investment.

Get in touch with ESD Solar today, and let’s illuminate your path to a sustainable future!

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