What are Solar Panels and How does Solar Energy System Work

This article will give you an understanding of solar panels, what are they made of? How do solar panels work? And how important it is to choose the right type of solar panel?

Before we get into our core topic, let’s begin with a few basics which will help you grasp the concept better.

Our Earth captures more than billions of photons (tiny packets of energy) from the sun which is a natural nuclear reactor. It is the sun which determines the climate and supports life on our planet in the form of heat and light. Did you know these amazing statistics that less than two hours of sunlight striking our planet can fulfill our electricity needs for an entire year? Intercepts

Currently, solar power accounts for only a small portion of the total global energy mix but with more and more people investing in solar power; this technology is advancing rapidly. Although we care about our environment like most sane people, the cost impact of using solar power is also important for us.

We had a lot of questions regarding solar technology; so we did some research to find out how this technology works and how it would benefit us. When we talk about solar panels, we are talking about just one component of a solar energy system.

We would also advise you to read our detailed article on the solar energy system. 

What are Solar Panels?

The solar panel is also known as photovoltaic (PV) panel is made up of multiple cells stacked within an aluminum frame and covered on top by toughened glass. The main components of a solar panel are as follows:

  1. Frame
  2. Glass
  3. Encapsulant
  4. Solar Cells
  5. Back Sheet
  6. Junction Box
Solar Panels Breakdown
Courtesy DUPONT

While most reputed solar panel manufacturers do their own manufacturing from scratch. However many panel manufacturers use externally sourced components and assemble solar panels.

Please read EnergizedPAK’s article on solar panel construction.

How do Solar Panels Works?

Solar panels directly convert sunlight (photons) to electricity (voltage). When sunlight (photons) hits a solar cell, electrons are knocked out of their respective atoms and if conductors are attached to the positive and negative sides of a cell, it forms an electrical circuit. When these electrons flow through an electrical circuit they generate electricity.

Solar or PV solar panels generate direct current (DC) electricity. With DC electricity, electrons flow in one direction around a circuit. This example shows a battery powering a light bulb. The electrons move from the negative side of the battery, through the lamp, and return to the positive side of the battery.

With AC (alternating current) electricity, electrons are pushed and pulled, periodically reversing direction, much like the cylinder of a car’s engine. Generators create AC electricity when a coil of wire is spun next to a magnet. Many different energy sources can “turn the handle” of this generator, such as gas or diesel fuel, hydroelectricity, nuclear, coal, wind, or solar.

Solar or photovoltaic (PV) Cells

In the mid-1950s, Bell Telephone discovered that an element found in the sand called silicon (Si) creates an electric charge when exposed to sunlight. This led to the discovery of solar cells that capture the sun’s energy and convert into electricity.

Simply put, a solar cell is a semiconductor device made up of wafers of pure silicon (Si) doped with special impurities, which convert sunlight either visible light, ultraviolet (UV) radiation or infrared (IR) radiation into direct current (DC) by using photovoltaic action of the cell without the use of any moving parts.

Solar cells or PV cells operate according to the photovoltaic effect. Here, “Photo” means light and “Voltaic” means electricity. They are constructed with a positive and negative layer which together creates an electric field.

You can read EnergizedPAK’s detailed article on Solar or Photovoltaic (PV) cells.

Types of Solar Panels

As you’ve read previously, solar panels collect and convert sunlight into electricity. Whenever you evaluate solar panels for your house, office or business, you will encounter two main types of solar panels:

  1. Poly-crystalline or Multi-crystalline Solar Panels
  2. Mono-crystalline Solar Panels

Both types of panels serve the same purpose of producing electricity from sunlight, but there are key differences you should be aware of.

Poly-crystalline or Multi-crystalline Solar Panels

Imagine loading a bucket containing 1500 pounds (lbs) or 680 kilograms (kg) of silicon rocks into a 3 foot by 3-foot quartz mold to create a square shape and then loading it into a 2500 degree Fahrenheit furnace. It takes about 20 hours to for the silicon rocks to melt and about 3 days to cool down.

A poly-crystalline panel has a blue mottled look, like a piece of particle board; it looks like it is made up of multiple chips of silicon pressed together. That’s actually caused from when the melted silicon cools and hardens; it crystallizes like frost on a window. When it is sawed into the wafers, there’s much less wasted material from the square ingot than from the round mono-crystalline ingot.

Poly or Multi-crystalline cells are manufactured from are solar panels are made from multiple small silicon crystals melted and joined together to form wafers for the panel. The manufacturing process of poly-crystalline solar panels is simpler, less wasteful and quite cheaper compared to mono-crystalline solar panels.

Check out the Advantages and disadvantages of Poly-crystalline or Multi-crystalline solar panels below.

Mono-crystalline Solar Panels

Mono-crystalline solar panels are made from a single silicon crystal block melted and joined together to form the wafers for the panel. The manufacturing process of poly-crystalline solar panels is simpler, less wasteful and quite cheaper compared to mono-crystalline solar panels.

How Does a Solar Energy System Work?

Here’s an example of how a home solar energy installation works. First, sunlight hits a solar panel on the roof. The panels convert the energy to DC current, which flows to an inverter. The inverter converts the electricity from DC to AC, which you can then use to power your home. It’s beautifully simple and clean, and it’s getting more efficient and affordable all the time.

However, what happens if you’re not home to use the electricity your solar panels are generating every sunny day? And what happens at night when your solar system is not generating power in real-time? Don’t worry, you still benefit through a system called “net metering.”

A typical grid-tied PV system, during peak daylight hours, frequently produces more energy than one customer needs, so that excess energy is fed back into the grid for use elsewhere. The customer gets credit for the excess energy produced and can use that credit to draw from the conventional grid at night or on cloudy days. A net meter records the energy sent compared to the energy received from the grid.