Here’s What You Need To Know About Solar Panels


Renewable energy is quite a hot topic these days. Sri Lanka’s infrastructure for providing energy to its citizens is by and large by Hydroelectricity. There is a more powerful source of energy though. It’s a giant ball of hot plasma that generates massive amounts of heat, known as the sun. With advancements in technology, it is possible to harness the power of the sun to power various electronic components through equipment called Solar Panels.

What is a solar panel?

Simply put, a solar panel is a panel that can absorb sunlight and then convert it into electricity using a process known as Photovoltaics. This effect is the creation of electric current in a material that is exposed to light.

Solar PanelsFirst introduced in 2011, Solar panels have come a long way in terms of technological advancements and material design. They can be mounted on to the rooftops of buildings, houses and apartments. They can even be used as separate units making them extremely flexible as an alternative power source. From solar street lights, to solar powered vehicles to even powering your smartphone or caluculator.

How does a Solar Panel work?

A solar panel allows particles of light, or photons, to literally crash into atoms, thus releasing electrons and generating a flow of electricity. A typical solar panel is made up of a number of photovoltaic cells. Each cell is made up of two slices of silicon or similar semi-conducting material. These cells create an electric field and each slice is given either a positive or negative charge.

Solar Panels
The internals of a Solar panel
Image Credits: Visual Capitalist

Delving a bit further into this, the top layer of silicon is coated with phosphorous, adding extra electrons to create a negative charge. The bottom layer gets a coating of boron, resulting in fewer electrons leading to a positive charge. Once a photon of sunlight hits an electron free, the electric field generated will push the electron out of the silicon.

What else is needed for a Solar Panel to generate electricity?

Once the electrons start jumping around to create an electrical field, metal plates are placed on the sides of the cell to collect the electrons, transferring them to wires. Once done it’s just a matter of transferring the electricity to wherever its needed.

A typical solar panel setup, also referred to as a photovoltaic power station would require a number of components in order to operate. Apart from the Solar panel itself, you would need a mounting system. These are racks that are used to mount solar panels to roofs, facades and even the ground.

You will also need cables. These are not ye average cables you can pick up from your local hardware. Rather, these are cables that are laid outside and connect solar panels to other components. They are both weather and UV resistant, capable of withstanding a large temperature range.

Solar PanelsIn case you were wondering, A solar panel creates DC (Direct current). Our home appliances run on AC (alternating current). This is where an inverter comes into play. The purpose of this device is simple: convert DC power generated by Solar panels into AC power. Solar panels absorb sunlight during the day to produce electricity, but what about in the night? Or when it’s cloudy (with no chance of meatballs)?. That’s when you need a battery. These store the generated electricity so that they can be used as a backup power source if sunlight is insufficient.

Solar PanelsAnother key component you would need is a Charge controller. This essentially regulates the voltage produced by the solar panel so that it doesn’t damage the battery. Remeber, the higher the levels of photons that are absorbed by the panel, the greater the amount of power (electricity produced). This can cause a voltage fluctuation and damage connected components such as a battery or even appliances.

Solar PanelsWhere can I get Solar panels from and how much will it cost?

Whether or not you need a Solar panel depends on how much your current electricity bill is and how many units of electricity (measured in kWh) you’re using each month. If you’re using anywhere less than 199 units, then you’re better off staying connected to your local electricity grid as it makes no sense to install a Photovoltaic system to your house.

However, if you’re consuming anywhere between 200-2500 units at a non-commercial level, then you can consider harnessing the power of the Sun to power your appliances. If you search online, the most popular results are JLanka Technologies and KMH Solar. KMHSolar’s pricing options start off at Rs. 343,286/- for a system that generates around 85 kWh/month, with a system size of 750W. A system of this size would require around 54 square feet. From there, the systems scale up in terms of energy generation, system size and required roof area. Installation for all these usually takes around 1-2 days.

Taking the my house as an example, i requested a quotation from KMHSolar. On average, we use around 300 units of electricity per month and the final bill is around LKR 7000-8000. Two days later, the quotation was in my inbox.

Solar Panels
The quotation I received from KHMSolar

As you can see from the results above, to fully power my house on solar power, with no reliance on electricity from the local grid, whatsoever, it will cost around LKR 610,000/-. The quotation is quite detailed specifying items, quantity, pricing and warranty. A total of 10 solar panels are used  with a total kilowatt power output of 2500W and an expected average output (in KwH) of 300 kWh units which is what is currently in use. If you’re considering whether to go Solar or not, this can be a good stepping point.

Factors to consider when getting a Solar panel

While you still can’t casually walk up to your nearest hardware depot and pick up a couple of Solar panels and fix them, there are a number of places that you can inquire from in order to get the information you seek. For starters, it’s not going to be cheap. Installing a solar panel is a long term investment. You can’t simply decide that you want it one day and dispose of if the next day.

That being said, there are several factors to consider if you’re going ahead with installing a photovoltaic system aka a solar panel system.

  • Firstly, you’re going to have to see what your requirement is. Various solar panels have various uses such as residential, commercial and industrial purposes. Make sure you get the correct panel for your requirement.
  • You will also need to know how much of energy is needed to power your house building. This depends on the number of electronic devices used, how many people are living in the building etc. You can usually get a rough idea by observing the amount of units marked on your electricity bill and then calculating the panels required accordingly.
  • Once that is done, check the efficiency of the panels. This involves calculating the rate at which the panels convert solar power to electricity. The higher the efficiency, the lesser the number of panels you will need.
  • Next, find the best area of your house or building that receives the most amount of sunlight. There’s no point spending all that money if you fix a fleet of solar panels to where the sun doesn’t shine, literally. The more sun shines on your solar panels, the more energy that will be generated.

Make sure that no tall objects such as trees or other buildings don’t cast shadows on the panels else they cannot absorb sunlight. Also ensure that the roof of the building or house is sufficiently durable to ensure the weight put by the panels and the mounting racks.Here's What You Need To Know About Solar Panels 1

  • Ensure that the layout of the root and materials used are all strong enough to withstand the duration of the system. As these systems usually will be operational for around 10-15 years, it’s important that your roof too is that durable.
  • If you’re not financially stable, stay away from installing a solar panel system If you suddenly find that you don’t have enough finances to finish the job or you cannot afford the maintenance cost, then things are going to be pretty dark.
  • It’s also important to look for companies and professionals who can offer proper warranty in case something goes wrong. There’s no harm in asking around from others who have solar panels installed to see who they got the systems from. Be sure to get a good warranty period and make sure you know exactly what is covered in the warranty period. You can even check online for reputed companies and read reviews to see how they’re rated.

How do Solar Panels affect your electricity Bill?

As you saw from the quotation above, roughly around LKR 600,000/- will be needed as a one-time payment to fully power my house via solar power. Do the math and you’ll see that this is essentially how much would be spent for the next 6 years at LKR 8000/- per month. While this may look like a steep initial investment, if you have the finances to support it, then you will no longer need to pay your electricity bill or you’ll pay the bare minimum amount in the event that you need to use the local electricity grid.

Solar PanelsIn order to calculate your ROI or Return on Investment when going Solar, take a look at the last 12 months of your electricity bill to figure out your average monthly electricity bill. Once that is done, calculate the total cost of a solar energy system. After that is done, determine how much you pay per kilowatt hour (kWh).

A simple formula to use here would be where the Solar Payback Period equals the initial Net Investment divided by the Yearly Benefit. So, if your solar panel costs LKR 610,000/- and your yearly benefit was LKR 96,000/-, the payback period would be 6.3 years.

In fact, when your solar power system generates more electricity than is needed for your house, the excess power flows back to the utility grid. If you speak with your local electricity supplier, you could even get paid for giving back electricity to the local grid. Certain terms and conditions may apply for this, but it’s a start to saving money.

Are there any cons to getting a Solar Panel system?

Solar panel systems or photovoltaic systems as they’re technically called are not 100% perfect. They too have their drawbacks.
For example, if there’s no sunlight, then there’s no way to generate solar power. Depending on your location geographically, solar power generation may vary. If there are tall buildings casting shadows over the system, then that too would affect solar power generation.

The next con is the initial investment. Unless you have the cash to splash, opting for a photovoltaic system is a costly venture. Even a basic system will cost you upwards of LKR 100,000/-. Adding to this is the cost of maintenance. Photovoltaic panels need periodic cleaning to ensure that dirt and debris do not hinder efficiency. If there is a severe lightning storm, you also risk the system getting hit by a bolt of lightning.

Solar PanelsThere’s also the cost of implementation. Apart from the photovoltaic system itself, you may have to carry out repairs to your roof or alter your house’s physical infrastructure to make room for the system. Depending on the level of reconstruction needed, this can be a huge cost.

Storing energy can be expensive. Even though energy storage systems such as batteries will aid you in storing generated energy for later use, these technologies are also expensive.

In conclusion

As you can see, photovoltaic systems or solar panel systems do offer a method to significantly reduce your electricity bill and can even bring you extra income by recycling generated energy to your local electricity grid. True enough, it is expensive, but it has its advantages such as generating less pollutant power when compared to fossil fuels and help create a cleaner tomorrow. As with any technology, there are drawbacks as well. In the end though, the choice is up to you. If you feel that you can benefit from PV technology, then by all means go ahead. If you have a system


  1. Thanks lot for your infomation….
    its great collection of all infomation of solar….
    i think up to now solar is not beneficial on cost ,if you have General purposes CEB conection or domestic conection which monthly consumption less than 250 unit.

  2. Thanks for the compiled information. However is it possible for you to comment on the efficiency rates of the solar panels available in the domestic market?


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