How Do Solar Panels Work?

With our population nearing 8 billion people and growing by 200,000 per day, our world has never been so hungry for energy. But our energy consumption has led to environmental changes that impact us all and resources are finite.

In our search for clean, renewable energy sources, it was inevitable that we would look to the skies. After all, the sun has been providing the Earth with energy every moment of the day since its creation.

Why Solar Power?

One of the main advantages of solar power lies in the reduction of pollution from power generation, as there are zero emissions from generating power with solar systems. Another key advantage is that it is effectively limitless and comes to us free from the sun without any effort on our part. In addition to generating electricity, solar power can also be used for heating by deploying solar thermal systems that can convert sunlight into usable heat.

Can solar power provide enough energy for the whole world?

According to the US Department of Energy, the sun hits the Earth with 430 quintillion Joules of energy every hour, a number large enough to appear somewhat abstract. To have a better idea of what this means, imagine 430 followed by 18 zeroes.

By way of comparison, if we total the amount of energy used by the Earth as a whole, it comes out to approximately 410 quintillion joules each year. In other words, in a single hour, the sun gives us enough energy to power our planet for an entire year.

The main issue is not whether the sun offers enough energy, but rather, how do we capture and make use of that energy? That’s where solar panels come in.

Solar Photovoltaics

Solar power is a hot topic these days, but it isn’t exactly new. In 1839, a young physicist named Edmond Becquerel was working in France when he observed and discovered the photovoltaic effect, which is a process producing electric current, or voltage, when exposed to light. Years later, Becquerel’s work served as an inspiration to Augustin Mouchot, a French mathematician. Mouchot started registering patents during the 1860s for solar-powered engines.

By 1883, the first solar cell was created by New York inventor Charles Fritts when he coated selenium with a thin layer of gold. His invention only had a conversion rate of 1 to 2 percent, but it was a great development that started us on the road toward the solar panels that followed. Only a few years later in 1888, the first solar cell based upon the photovoltaic effect was created by Russian scientist Aleksandr Stoletov.

In the 1950s, researchers at Bell Laboratories found that materials such as silicon were more efficient than selenium. This resulted in the creation of a solar cell with 6% efficiency. In April of 1954, they demonstrated the first practical silicon solar cell, but the cost made it prohibitively expensive for most people. It was only in 2000 that photovoltaic modules began mass production.

Today’s photovoltaic cells have become much more affordable, as well as more efficient, operating at an efficiency of 15 to 20 percent.

How Do Solar Panels Generate Power?

Solar panels collect sunlight, converting it into energy usable for multiple purposes. Each solar panel is made up of individual solar cells, which in turn, are made up of layers of silicon, boron, and phosphorous. The boron provides a positive charge, while the phosphorous provides a negative charge. Solar panels will absorb photons (light particles), creating an electric current by doing so. As these photons strike the solar panel, electrons are knocked out of their atomic orbits, into an electric field generated by the solar cells. These free electrons are then pulled in a directional current, causing electricity to flow.

The solar system of a typical home can generate enough electricity for all its needs and even produce additional solar electricity to send to the main power grid, or to a battery bank for use at night.

Benefits of Solar Power

Solar panels are an excellent means of generating power for multiple applications. To many, the potential for saving money while also investing in a technology that is helping to save the planet is one of the greatest advantages of solar power. A growing number of farms and agricultural businesses are looking to use solar energy power their needs. Solar energy is a great way to produce sustainable power while also saving on overhead costs.

The other obvious advantage of solar power is that it is a clean and renewable energy source. For those looking for ways to contribute to a cleaner environment, this might be its greatest advantage. The topic of climate change has its proponents and detractors, but regardless of where one stands, a clean environment is always going to be preferable to one that is polluted.

Some worry about the cost of solar panels, but you can begin saving right away on electrical bills. Once they have paid for themselves in electricity bill savings, you will continue to produce free, clean energy for the remainder of the system’s lifespan. With no moving parts to break down, solar panels can last several decades if cared for properly and depending on the system’s quality. Very little maintenance is required beyond ensuring that the panels remain clear of obstructions.

From the moment the system is up and running, the monthly cost of electricity will be reduced or even eliminated completely. In fact, if your system produces more electricity than you consume, excess power can be sold to your local utility company, sometimes at a premium. Some areas in Canada also offer rebates on solar panels.

Some other benefits of solar power are often overlooked. For example, if you decide to sell your home, potential buyers will understand the benefit of buying a house with solar power, potentially increasing the resale value. Additionally, solar panels mounted on your home’s roof help to protect it from the elements, increasing the effective lifespan of your roof.

How Do Solar Panels Work With Electric Companies?

Most homes with solar panels will still have times when they must draw upon the grid to meet their needs because their panels are not generating enough power. This may happen during overcast or rainy days and at night.

The other benefit of remaining connected is the ability to send power back to the grid. If no one is home on a particularly sunny day, there is likely to be a surplus of energy.

Most homes will use the most energy in the morning when everyone is getting ready for work or school, and again at night once they return home. During the rest of the day, energy use tends to be much lower, meaning that much of what is produced by the solar panels can be sent back to the grid. This will earn the homeowner a credit that will be applied toward whatever they draw for their own use. The more energy that can be sent to the grid, the greater the credit received. Your electricity bill will be based on the amount of energy consumed relative to the excess produced and sent back.

Homes that are still on the grid are connected via a bi-directional electricity meter or a separate outflow meter. Like a normal meter, this will measure the amount of energy that you are drawing from the grid at night and during sub-optimal weather conditions, but it also measures the amount of energy being sent back during those times that you are producing a surplus.

See how much power solar panels produce

When homeowners participate in their utility company’s net metering program, they will receive a credit for every kilowatt-hour (kWh) of energy that they send back to the grid. This credit can then be applied to any future consumption during periods when the solar panels cannot meet the demands of the home.
Although many homes use less electricity during the day, it is also the time when most businesses are operating, creating an increased demand overall. The excess energy sent to the grid from solar-powered homes helps to offset this greater demand and smooths out the grid’s demand curve.
This relationship with solar-powered homes also benefits the electrical utility company by lowering their costs. Having solar energy entering the grid will reduce grid stress, translating into reduced expenses for maintenance. This, in turn, leads to lower operating costs.

Solar panels have come a long way since their creation, and they continue to evolve. As they become increasingly efficient and less expensive, they represent an ever more attractive option for those who wish to help improve the environment while saving money.