How Do Solar Panels Work?

Solar panels convert sunlight into electricity. Unique semi-conductive materials from which the photovoltaic cells are made absorb the photons of sunlight which causes negatively charged electrons to be released from their atoms. The flow of electrons creates a usable electrical current.

Residential photovoltaic Solar installations have increased by 34% from 2020 to 2021. 2022 Has seen a similar trend, with about 8% of American homes using solar panels.

The solar energy generated by panels annually in the US alone is sufficient to power 24 million homes.

Over the past five years of installing solar energy systems, I’ve seen a massive influx of different solar panels becoming available for the domestic market.

One thing that they all solar panels have in common is how they work. In this post, I’ll cover the topics you see below:

β˜€οΈ How Do Solar Panels Work?

Photovoltaic cells are used in many applications to power items from as small as a wristwatch to large commercial applications.

The photovoltaic cell is highly versatile as the cells can be connected to other cells to generate more electricity.

The PV cell’s semi-conductive material is the key to a solar power cell’s ability to generate electricity from sunlight. Silicone crystals are by far the most widely used semiconductor in solar panels across the world.

Other materials that lend themselves superbly to use in solar panels are:

A significant advantage of a solar panel is that it contains no moving parts that can wear down. The PV cells’ semiconductor materials mentioned above are double-layered. The N-Type (negative) and the P-Type (positive) have the unique ability to release a virtually continuous supply of negatively charged electrons. 

When sunlight lands on the N-Type silicon layer, it releases negative electrons, which are attracted to the P-Type Silicon layer. The imbalance caused by the electrons attracted to the positive layer causes an electrical current harnessed from each PV cell to make up a large solar panel. 

The output of the Volt’s Amps and Wattage generated by a solar panel is directly related to the number of PV cells it contains.

Watts is the measure used to signify the output and to market the solar panel. Solar panels are available in various sizes depending on their application.  

The solar panels are useable on their own or linked together when more power needs to be generated. A solar panel generates a direct current which is perfect for charging batteries but requires conversion to alternating current (AC) for use in the average home by installing an inverter.  

An inverter is required for use with solar panels for any application where solar panels power 110-volt, 220-volt, or 380-volt alternating current circuits.

Three basic solar systems are used in the Solar Industry. 

System TypeBattery Yes / NoGrid Back UpApplication
Off-GridYesNoHome, Business, RV’s, Camping, mobile units, etc.
HybridYesYesHome and Business
Grid-TiedNoNoHome and Business

Off-Grid systems are ideal for use in areas where no electrical grid infrastructure exists and consist of solar panels, an inverter, and batteries for nighttime energy use.

Smaller off-grid systems, which operate like those used in homes, are ideal for use as portable units and in RVs and fish houses.

Hybrid systems use solar panels, battery storage, and an inverter and use the national electrical grid as a backup power source. 

Grid Tied systems only use solar panels and an inverter and is linked to the national grid. Grid-tied systems save the end user money in the daytime but don’t work at night or when the grid power is interrupted. 

Solar PV panels used in portable solar systems, such as those used to power a campsite, RV, Solar EV charging station, your home, or commercial application, all work similarly to produce electricity with energy from the sun. The difference is the size of the PV array that is required.  

🦾 Solar Panel Efficiency

Solar panel efficiency is a measurement used to express the solar panel’s ability or efficiency to convert available sunlight into electricity as a percentage. 

Like many things in life, not all solar panels are equal. Factors such as the electrical components, quality of the semiconductor and other materials used, and the manufacturing methods used in making the solar panel directly affect the efficiency of the individual solar panel.

Considering solar panel efficiency is less critical in regions where sunlight is abundant but in areas where daylight hours are limited, choosing a solar panel delivering maximum efficiency is essential to ensure advantage is taken of the little available sunlight. 

Solar panel efficiency ratings of between 18% and 23% are the norm for most solar panels today. 23% Is considered highly efficient, meaning the solar panel can effectively utilize 23% of the available sunlight striking the surface of the solar panel.  

🌟 Most Popular Solar Panel Types

The four common types of solar panels available today are listed below, but in total, twenty-five types of solar cells exist:

  • Polycrystalline
  • Monocrystalline
  • PERC – Passive emitter and rear contact cells
  • Thin film 

Polycrystalline Solar Panels:

Poly panels, as they’re often referred to, are made from compressed shards of silicone crystals that are artificially bonded to form a crystal which is then sliced to create the PV cell.

Poly solar panels are easily recognizable by their light blue surface color and scale pattern. 

In terms of efficiency, the poly panels lie at the bottom end of the scale, topping out at 20% efficiency. Polycrystalline solar panels are popular due to their lower cost and long lifespan. However, they have a shorter life cycle than monocrystalline solar panels. 

Monocrystalline Solar Panels

Mono solar panels PV cells are cut from a single silicon crystal. As the crystal is purer, the mono solar panels deliver excellent efficiency of up to 23% and last the longest. 

Mono solar panels are dark blue to black in appearance and don’t have the distinctive scale pattern of poly solar panels. 

PERC – Passive Emitter And Rear Contact Cells

Amongst the newest solar panel technological changes in pursuit of ever more efficient solar panels are the PERC solar cells. For easy identification, these are also called Mono PERC solar panels.

PERC Solar cells are modified monocrystalline solar panels with an additional reflective layer inserted under the PV cells, reflecting unabsorbed sunlight back through the PV cells for reabsorption. 

Adding the reflective layer within the solar panel increases the module’s efficiency by up to 12% compared to standard monocrystalline solar panels. Their lifespan is as good as traditional mono solar panels. 

The PERC solar panels lend themselves well to areas where lower sunlight conditions are experienced as they offer the maximum possible efficiency to be extracted from the available sunlight.   

Thin Film

Thin film or flexible solar panels are a specialty item produced for applications where standard framed solar panels are impossible to use. Thin film solar panels are ideal for curved surfaces, cylindrical poles, or even curved vehicle roofs or caravan roofs.

Thin film solar panels have a shorter lifespan than conventional solar panels and are less efficient. Thin film solar panels produce efficiency levels between 7% and 18%, significantly lower than the average poly or mono solar panel. 

The advantage of thin film solar panels comes into play when used in scorching environments. Their improved heat tolerance often makes them more efficient than mono or poly panels, where the temperature coefficient reduces their efficiency in these hot environments.

❓ FAQs

How Do Solar Panels Work When There’s No Sun?

Solar panels require sunlight to perform optimally; therefore, they cannot produce electricity without sunlight. Solar panels can generate low levels of power from light reflecting off the moon, but in virtually all instances, the power generated is too little to be useable.

When cloudy in the daytime, the photons of light reflect off and penetrate the clouds making it possible for the panels to work. 

How Does A Solar Panel Generate Electricity?

Solar panels are made from two layers of semi-conductive material, commonly silicone crystals. They are called N and P-Type layers.

Sunlight absorbed by the photovoltaic cells causes the negatively charged electrons to be dislodged from the N-Type layer and to flow to the P-Type layer.

The reaction produces electricity that is stored in batteries or used to power homes or businesses and for other suitable applications. 

Can You Run A House Just On Solar Panels?

Solar Panels generate a direct current, meaning the electricity needs to pass through an inverter that changes the current to alternating current and regulates the current flow for it to be useable in a home. 

The electricity generated can be stored in batteries for night use or when grid power is unavailable. Alternatively, the inverter must be linked to the grid as backup power instead of batteries. 

πŸ”‘ Key Takeaways

1️⃣ Solar panels work by absorbing photons of light to generate electricity and store renewable energy.

The sunlight dislodges the electrons in the PV cells’ negative (N-Type) semi-conductive material layer. The positive (P-Type) semi-conductive materials attract the freed electrons, which causes useable electrical.

2️⃣ The direct current (DC) generated by the solar panels is storable in batteries for later use.

To use the stored DC in a home or business, the current must pass through an inverter that converts the current to alternating current (AC) and provides the correct voltage, 110V, 220V, or 380V.   

Now that we’ve shared the facts on how solar panels and solar power work, all that’s left for you when you go solar is to determine the type, size, and quantity of Solar Panels you’ll need to get started on your own solar panel-powered solar system.

I’m the website operator and editor here at ALTA Devices. The solar revolution is the most exciting thing to happen in a generation! I’ve written extensively on solar, electric vehicles, and the electrification of the marine industry. You can find out more on LinkedIn below: