The solar panels have evolved from a giant structure to a small solar chip. With the advent of technology across the globe, solar panels are available in different shapes and sizes. Well, now you don’t just install them on the roof. You can place them inside a building or vehicle. But, can you put them behind glass?
Surprisingly, yes. Yeah, you heard it right. We can place the solar panels behind the glass. Will they be as effective as if they were installed out? Certainly not. But, that is not bad news because the benefit from the remote placement of the panels is still welcoming.
In this article, let us discuss how solar panels work behind glass and the other aspects. Let us get started.
How do solar panels work?
Solar panels are made up of Photovoltaic cells and sandwiched between silicon or glass, a semi-conductive material.
The silicon combines with other elements like phosphorus and boron to establish the electric field to the PV cells to create a negative and positive charge. They work together to create a positive and negative charge, producing electricity.
The sunlight, made of several photons, hits the solar panels and the PV cells. These photons are collected by the conductive plates and can create electricity.
Why should you place the solar panels behind the glass?
It is good to know that solar panels can work behind glass. But why would you want to place them behind the glass? There are several reasons you might want to do that, and let us look at them.
- Solar panels are not low cost. If you live in an area where the risk of stolen solar panels is relatively higher, you might certainly want to place them behind the glass windows, and you can risk your investment rite.
- The caravan or motorhome is the most common place where solar panels are placed behind the window.
- Some people don’t prefer drilling their roofs. If that is the case, placing them behind the glass would be better.
Will my solar panel generate electricity behind glass?
Yes. The solar panels can generate electricity behind the glass. For understanding the methodology, we need to analyze the different ways and ranges in which the glass can affect the sunlight. Shall we start the analytical job?
According to the Fresnel Laws and Snell Law, when light travels in a speed and direction and falls on the surface of another media, say, for instance, a glass of water, a portion of the light is reflected into the atmosphere and the rest is refracted inside the surface of the media. The angle and speed at which the light is refracted may differ from the angle and speed of reflection.
This difference in angle and speed depends on a coefficient known as the Refraction index of the media, and this coefficient may vary depending upon the type of glass.
So, how do this reflection and refraction affect the solar panel?
Some of the light received from the sun is reflected in the atmosphere. So, all the photons flowing through the sun are not directly received by the solar panels, and some are reflected. The solar panels will lose those photons that are reflected and will not produce electricity to that extent.
Orientation and sun’s position
The Orientation of the solar panels towards the sun is essential to optimize the output. Placing the solar panels behind the glass, inside the house, or a vehicle is a horrible idea, and it would help put your solar panels facing the south (US).
If you are placing the solar panel in a vehicle and constantly moving, then the Orientation keeps changing, and so does the level of energy obtained.
If you plan to place the solar panels inside the house, make sure you find a perfect south-facing glass window that can quickly assist the solar panels. Keep in mind that placing the solar panels under the north-facing glass is equal to not having the solar panels.
Further, placing the solar panels behind the tinted glass windows may negatively affect them. When the sun is in its highest position during the mid-day, the solar irradiance will be at its maximum. Placing the solar panels inside the house blocks the flow of the highest irradiance directly on the solar panels, and they will not be able to take advantage of the best time to absorb the energy.
DNI and DHI
Solar irradiance is a salad of two types of irradiance – Direct Normal Irradiance (DNI) and Diffuse Horizontal Irradiance (DHI).
DNI/ is described as the sun’s location at a perpendicular angle directly to the solar panels. There is no reflection, retraction or loss.
DHI is a situation in which the solar radiation is reflected and refracted by the atmosphere, clouds, lakes, mountains or the ground. DHI is defined as that component of solar irradiance that indirectly affects the surface of the solar panels.
If you place the solar panels behind the glass, you would probably be eliminating the DNI component that would directly affect the solar panels. It means your solar panels will be working along with the DHI components.
Shadings and Thermal Losses
One of the significant disadvantages of placing the solar panels inside the house or behind the glass window is that the shades of the windows and bars would prevent the sun rays from falling into the solar panels. The light falling on the panels is already minimal and on top of it, if there are shades, imagine how solar panels produce electricity.
If you have placed the solar panels on your car, thinking that the sun rays would directly fall on the solar panels, there is no way of any losses. If yes, wait a minute. The temperature inside the car increases as you keep them under the sun for a long time without an air conditioner. The solar panel will get hotter because of the electricity generation and the hot temperature inside the car. When there is too much heat, the solar cells might be damaged, which will also induce thermal loss.
Is it worth installing solar panels behind glass?
As discussed above, several reasons justify why you must not place the solar panels behind the glass. Well, that does not mean it does work behind glass, and the output level will be relatively lower for the amount you spend on the installation. So, if you are planning to purchase a solar panel, that is indeed a great idea. But, placing them inside the house behind the glass is not a great idea.
How to optimize the panels for use behind the glass?
After so much discussion, worry not if you still prefer to place the panels behind the glass. We will give you ideas about optimizing the panels for use behind the glass.
- First and foremost, use the south-facing window to place the solar panels, and it helps you get as much light as possible to the panels.
- If you have a smaller panel that can be portable, move them to different directions in which the sunlight is maximum. This helps in increasing the productivity of the panel.
- To avoid shadows and refraction, try to place the panels as close as possible with the windows.
- You can also try keeping the windows open and letting the direct sunlight flow to the surface of the panels.
So now, let us answer the same question. Do Solar Panels work behind the glass? Yes. They do. But do you want to place them behind the glass after knowing all the pros and cons? If yes, please do not expect them to provide the optimum output they can if not placed behind the glass.
If you plan to meet your house’s entire electrical needs from the panels, then placing them behind the glass is certainly not feasible. The investment you make would override the benefits, and it would be suitable if you want to charge small devices.
The glasses, infact create a greenhouse effect between the panel and the glasss, which might degrade the efficiency of the panel—the greenhouse effect results in increasing the temperature of the solar panels.
Furthermore, the sunlight entering the home through the glass windows is also used and absorbs any other objects in the room. In that case, think about the total solar loss that you need to face.
You lose a few photons through reflection, orientation, shading, thermal loss, and now other objects could also take a portion of your sunlight. And all of this for a high cost? It would help if you thought about it.
If you are still persistent about placing them under the window, make sure you follow the measures that we have suggested to improve the efficiency and get optimum results from the panels placed below the glass windows.
We hope you have a tremendous solar panelling experience. Let us save energy and save the earth.