Let’s face it, we all love the sun. In fact, we wouldn’t be here without it. Generating electricity from sunlight has been around for a while, but how does solar energy work exactly? The sun emits light, it warms up the planet but it does so much more.
Since 1839 we know of the existence of solar energy, and since the 50’s we have been able to really harvest this energy and use it. So how is the energy emitted by the sun, 150 million kilometres away (93 million miles) useful for us on Earth? Let’s have a closer look and answer the question: how does solar energy work?
How is solar energy produced?
The sun is basically a giant ball of plasma where nuclear fusion creates light and infrared radiation. That light (and radiation) needs about 8 minutes to reach the Earth. When sunlight hits our planet, about 30% of it is reflected back into space, due to the clouds, polar caps and oceans. The other 70% gets into our atmosphere. The gases there absorb some sunlight, but most of it reaches our surface. Despite having travelled millions of miles, this sunlight is still very powerful. A day in the sun without sunscreen shows you just how powerful.
The power of the sun has been used for many centuries. Sunlight and its heat were used to start fires as early as Ancient Greek and Roman times. The Romans also used sunlight to warm up water for their bathhouses. The most common example of using the energy from sunlight is of course, agriculture. Plants need sunlight to grow, we have known that since the dawn of time.
In 1839, Edmond Becquerel, a physicist from Paris, discovered the so-called photovoltaic effect. This is the generation of electric current due to exposure to light. He noticed that a silver chloride in an acidic solution generated a current when being illuminated while it was connected to platinum electrodes. He created a photovoltaic cell. His discovery was also known as the Becquerel effect.
How does solar energy work in solar panels?
Now that it was possible to create a cell to convert light into electric currency, the main struggle became efficiency. Even as late as the 80’s, harvesting solar energy was an expensive activity. There are two ways of turning sunlight into electricity. The most popular method is the one mentioned above, through photovoltaic panels (PV). The other technology is called concentrating solar-thermal power (CSP). Let’s look at PV panels first.
Photovoltaic Panels
When looking to get solar panels for your house, you will be looking at PV panels. Inside the PV panels, there are photovoltaic cells. These cells absorb the sunlight that hits the panels. The cells have an internal electrical field. The absorbed sunlight creates an energy that causes electrical charges to move within the cell. This way, the electricity moves around, creating a current. A single cell doesn’t produce that much electricity, but most panels have 60 or 72 cells. The current generated by the cells is Direct Current electricity, or DC. Since wall sockets use Alternating Current (AC), you will need an inverter to turn that DC into AC.
But how does solar energy work if there’s no sun?
Unfortunately, the sun isn’t out every day. And in some regions of the world, the sun is a lot more scarce than in other parts, so how does solar energy work then? Is it still possible to have solar panels in those cases? Yes, definitely. When you have solar panels at home, you are also still connected to the grid. Thanks to a switchboard you will first make use of the solar energy generated by your panels. But if there is none, then the switchboard will allow electricity from the grid to enter your network so you will never be out of power.
On days that you aren’t using all the electricity generated from the panels, the switchboard will allow your surplus to go to the grid. All energy you generate at home will either be used by you or be sent to the grid. No electricity will go to waste. The best part is, the electricity that you send to the grid will give you credits, which means you will get a discount on the electricity used from the grid. This process is called net metering. Depending on how much electricity you use and spend, you could be enjoying free power for the rest of your life.
Concentrating solar-thermal power
This is a technology that you won’t be using at home, how does solar energy work in concentrating solar-thermal power? CSP uses mirrors that redirect the sunlight over a large surface area. This sunlight will be reflected onto a receiver. Inside this receiver there is an amount of fluid that heats up by the sunlight. This causes a turbine to spin, generating energy. That’s where the thermal part in the solar-thermal power comes from. You may have seen CSP installations in action. In certain remote areas you’ll find large sites with many mirrors and a tower like structure in the middle. That tower is the receiver. In the picture above you see a large CSP site.
What can you use solar energy for?
In recent years, solar energy’s popularity has skyrocketed, and now it’s used for everything from charging cell phones to portable water heating and keeping entire towns running on electricity. With the advent of numerous solar devices, solar energy is now within the reach of both households and enterprises.
The ABFOCE Bluetooth Solar Speaker and the Solarbank Boombox are examples of a popular solar product that has seen increased demand. This devices combine the portability of a Bluetooth speaker with the environmental friendliness of solar energy. The solar-powered speakers can be charged by exposure to sunshine, making it perfect for use at outdoor events like picnics and camping trips.
The Jackery Solar Generator is another well-liked solar product because it can power a number of electronic gadgets while in transit. The ability to store solar energy and transform it into usable power makes this generator ideal for use in the great outdoors or as a backup power source in the event of a power outage. Larger items, such as backpacks and bags, are beginning to incorporate solar technology for charging electronic gadgets. For instance, the Solgaard Lifepack is a solar-powered backpack with an integrated solar panel to charge electronic gadgets while travelling.
The BigBlue Solar Power Bank and the the Solgaard Solarbank are two solar energy storage devices that can provide a significant amount of juice when you need it. These devices are ideal for use on camping vacations, at outdoor events, or in times of disaster due to their capacity to store significant amounts of energy from the sun. The X-DRAGON Solar Charger and the YELOMIN Solar Battery Charger are also gaining in popularity. These solar-powered battery chargers offer an environmentally responsible and sustainable alternative to conventional battery chargers.
Solar-powered fans, thanks to their low energy consumption and low environmental impact, have also seen a rise in demand in recent years. The motor in these fans is driven by electricity generated by the sun, which is collected by photovoltaic cells.
Last but not least, SunPower Solar Panels are a household name in the solar sector. The solar energy collected by these panels can be converted into electricity and used to power homes and businesses. SunPower Solar Panels are a preferred option for long-term solar energy investments due to its excellent efficiency and longevity. In conclusion, there is a vast selection of products available in the ever-expanding solar applications market to meet the demands of individuals and businesses alike. The applications of solar energy, from solar lanterns to solar watches, are practically limitless.
References
[1] Climate and Earth’s Energy Budget
[2] 30 percent of the energy sent to Earth bounces back into …
[3] Solar Radiation – Earth Science