Can Solar Panels Work Underwater? What It Means for Rooftop Solar in Kerala
Imagine being told that a solar cell can still harvest energy from sunlight after being placed underwater.
It sounds counterintuitive.
We normally think of solar panels as something that needs a clear, bright sky and direct sunlight. But researchers have been studying how solar cells can be designed to work underwater, where water absorbs and scatters much of the sunlight before it reaches the cell.
Research published in Joule explored how different solar cell materials could be better suited to underwater environments. The researchers found that certain wavelengths of light, particularly blue and yellow light, can penetrate water more effectively than others.
But this raises a more practical question for homeowners in Kerala:
If solar cells can harvest sunlight underwater, what does that mean for rooftop solar panels during cloudy days and monsoon weather?
The answer is more useful than the underwater technology itself.
How Can Solar Cells Work Underwater?
Solar cells do not necessarily need bright, direct sunlight to produce electricity. They need available light that can be converted into electrical energy.
When sunlight enters water, different wavelengths are absorbed at different rates. Red and infrared wavelengths are absorbed relatively quickly, while some blue and yellow light can travel deeper. This is why researchers have explored solar cell materials specifically suited to the underwater light spectrum.
This is very different from simply putting an ordinary rooftop solar panel underwater.
The research focuses on solar cells and materials designed or optimised for underwater conditions, where the available light is different from what a conventional solar panel receives on a rooftop.
That distinction matters.
The real takeaway is that solar energy generation is not limited to perfectly bright, cloudless conditions. The amount and quality of available sunlight determine how much electricity a solar system can produce.
And that brings us back to Kerala.
What Does Underwater Solar Research Have to Do With Kerala?
At first, underwater solar technology and rooftop solar in Kerala may seem unrelated.
They are connected by one simple factor:
Sunlight.
Water can reduce the amount of sunlight reaching a solar cell, but some usable light still remains. Similarly, clouds can reduce the intensity of sunlight reaching a rooftop solar panel, but they do not automatically stop solar generation.
That means a cloudy day does not equal a zero-generation day.
The amount of electricity generated will vary depending on cloud cover, sunlight intensity, panel orientation, shading, system design and other site conditions.
For homeowners considering rooftop solar panels in Kerala, this is an important distinction.
The question isn't:
“Will my panels work when the sky isn't perfectly clear?”
It is:
“How much electricity can my system realistically generate throughout the year?”
That is a much better question to ask before investing.
Do Solar Panels Work on Cloudy Days?
Yes, solar panels can continue generating electricity on cloudy days, although their output is generally lower than under strong sunlight.
The exact reduction depends on the thickness and type of cloud cover and the conditions at the site.
Kerala's weather changes considerably throughout the year, so solar system performance should be considered over longer periods rather than judged from one cloudy day.
KSEB notes that a grid-interactive rooftop solar system installed on a south-facing roof can generate approximately 4–6 units per day per kWp, with actual generation varying according to weather conditions.
This is why one rainy afternoon should not be used to decide whether solar is suitable for your home.
A properly designed system is evaluated based on expected generation, electricity consumption and site conditions over time.
Does Kerala's Monsoon Make Rooftop Solar a Bad Investment?
This is one of the first concerns many homeowners have.
Kerala's monsoon can bring long periods of cloud cover and rain. Naturally, solar generation can be lower during these conditions.
But that does not make rooftop solar unsuitable for Kerala.
A solar system is a long-term investment. Its performance should be considered across the entire year rather than based only on the monsoon season.
SolarMaster's existing guidance also notes that solar panels continue generating electricity during cloudy and rainy weather, although output can temporarily decrease during heavy rainfall.
The more important question is whether your system is properly sized and designed for your actual electricity requirements.
What Actually Determines Solar Power Generation?
Two homes with identical-looking roofs can produce different amounts of solar electricity.
Several factors influence the output of a rooftop solar system.
Roof orientation
The direction and angle of the roof affect how much sunlight reaches the panels throughout the day.
Shading
Trees, neighbouring buildings, water tanks and other structures can create shade that reduces generation.
System capacity
The number and capacity of panels need to match the household's electricity requirements and available roof area.
Inverter selection
The inverter plays an important role in converting the electricity generated by the panels into usable power for the home.
Weather conditions
Sunlight availability naturally changes with season and weather.
Installation quality
Panel placement, wiring, mounting structures and electrical design all contribute to the overall performance and safety of the system.
So when comparing solar installation companies, looking only at the number of panels or the quoted price doesn't tell you the whole story.
Should You Install More Solar Panels Just Because Your Home Uses More Electricity?
Not necessarily.
It is tempting to think:
Higher electricity bill = more panels.
But solar system sizing is more nuanced.
Your monthly electricity consumption is an important starting point, but the ideal system also depends on your roof area, available sunlight, energy usage patterns, future electricity requirements and the type of solar system you choose.
For example, a household that plans to add an electric vehicle may have very different future electricity requirements from a home with no major increase in consumption.
Similarly, a home that wants battery backup has different requirements from one primarily interested in reducing its electricity bill through a grid-connected system.
This is why a proper assessment is more useful than choosing a system based only on what your neighbour installed.
How Do You Know What Size Solar System Your Home Needs?
Start with your electricity consumption.
Your recent electricity bills can provide a useful indication of how much power your household uses. From there, the available roof area, sunlight exposure and system type can be evaluated.
For homeowners considering solar installation in Kerala, this is where a solar savings estimate can make the decision easier.
Instead of asking:
“How many panels should I buy?”
Start with:
“How much electricity do I use, and how much of that can solar realistically offset?”
SolarMaster's Solar Savings Calculator can provide an initial estimate based on your electricity bill and location, including a recommended system size and estimated savings.
Is Rooftop Solar Worth Considering for a Kerala Home?
For homeowners looking to reduce their long-term electricity costs, rooftop solar can be worth considering when the system is properly designed for the property.
The financial outcome depends on factors such as:
Current electricity consumption
Solar system size
Roof conditions
Available sunlight
Installation cost
Applicable subsidy or incentives
Electricity tariff
System performance
Future energy consumption
This is why there is no single savings figure that applies to every household.
A family with a high electricity bill, good roof exposure and suitable space may have a very different solar opportunity from a smaller household with limited roof space.
The goal should be to find the right system for your home, not simply the largest system available.
What Should You Check Before Installing Rooftop Solar?
Before choosing a solar installer, ask a few practical questions.
How much electricity will the proposed system generate?
Don't look only at installed capacity. Ask about expected generation.
Has the roof been assessed for shading?
Even partial shading can affect system performance.
Is the system sized according to my electricity consumption?
A quotation should be based on your requirements rather than a standard package.
Which inverter and panels are being proposed?
The components should be appropriate for the system design and site conditions.
What protection is included?
Earthing, surge protection, mounting and cable management are important parts of a safe installation.
What happens after installation?
Ask about monitoring, maintenance, warranty support and service.
SolarMaster's recent guidance on Kerala's climate also highlights the importance of considering monsoon rain, lightning, humidity, corrosion, earthing, surge protection and mounting quality when designing a solar system for the region.
The Bigger Lesson From Underwater Solar Research
Underwater solar cells are an interesting area of research because they show how scientists are adapting solar technology to environments where sunlight behaves very differently.
But homeowners don't need underwater solar technology to benefit from the idea.
The practical lesson is simpler:
Solar generation depends on available sunlight, not on perfect weather.
That is why a cloudy Kerala sky should not automatically rule out rooftop solar.
What matters more is understanding your property's actual solar potential, choosing the right system size and having it professionally designed and installed.
If you're considering rooftop solar panels in Kerala, don't make the decision based on one sunny day, one rainy week or a neighbour's system.
Start with your own electricity consumption and your own roof.
Ready to See What Solar Could Look Like for Your Home?
The first step doesn't have to be a sales call.
Start by understanding your potential savings.
Enter your electricity usage into SolarMaster's Solar Savings Calculator to get an initial estimate of your recommended system size and potential savings.
From there, a professional assessment can help determine whether your roof and electricity requirements are suitable for a rooftop solar system.
FAQs
Can solar panels work on cloudy days?
Yes. Solar panels can still generate electricity when the sky is cloudy, although generation is generally lower than under strong sunlight.
Do solar panels work during Kerala's monsoon?
Yes. Rooftop solar systems can continue generating electricity during rainy and cloudy weather, although output may decrease when sunlight is significantly reduced.
Can solar cells really work underwater?
Researchers have demonstrated that solar cells can harvest sunlight underwater. However, underwater applications require consideration of the different light spectrum and conditions found beneath the water.
Does underwater solar mean normal solar panels can be installed underwater?
No. Research into underwater solar focuses on materials and designs suited to underwater light conditions. It should not be interpreted as a recommendation to install conventional rooftop solar panels underwater.
Are rooftop solar panels suitable for Kerala?
Rooftop solar can be suitable for Kerala when the system is properly designed according to the property's sunlight exposure, roof conditions, electricity consumption and system requirements.
How much electricity can a rooftop solar system generate in Kerala?
KSEB states that a grid-interactive rooftop solar system on a south-facing roof can generate around 4–6 units per day per kWp, although actual generation varies with weather and other conditions.
How do I know what size solar system I need?
The right system size depends on your electricity consumption, roof space, sunlight exposure, future energy requirements and the type of system you choose. A solar assessment can provide a more suitable recommendation.
How can I estimate my solar savings?
You can use SolarMaster's Solar Savings Calculator to get an initial estimate based on your electricity usage and location.