Solar energy has really taken the world by storm over the past decade. The industry itself has grown exponentially and the cost of solar production has decreased over 70 percent. Solar energy has even become more inundated in mainstream media, houses, and businesses. But what is solar energy? And why has it gained so much popularity? Here are five interesting facts about the energy we harness from the sun.
1. Solar Energy Is the Most Abundant Energy Source
No, really. According to National Geographic, every hour the sun produces enough energy to power the entire world for a year. That means that by harnessing the sun’s energy for a single hour, every person currently living on Earth could forgo all coal, oil and natural gases for a year. This also means that filling the Mojave Desert’s 47,877 miles with solar panels would generate more than twice the electricity the United States uses annually.
To give a bit more perspective, Energy Informative compares the amount of solar energy absorbed by Earth every year to 40,000 times the total energy consumption in the United States and 8,000 times the consumption in the entire world. It would also be about 40 percent of the energy required to heat every drop of water on the Earth’s surface by one degree Celsius. That’s some serious power.
2. Solar Energy Is Everywhere
In early 2019, the United States installed its two millionth solar panel, just three years after installing their one millionth. This is because the costs of installation have decreased exponentially ($77 per watt in 1977 to $0.21 per watt in 2019) and the demand for individual home panels has increased.
Chances are, there are solar panels on a home near you. Homeowners are installing panels as the cost of grid electricity begins to rise. This investment usually pays off after seven or eight years and grants a 20-year savings of an estimated $20,000. Even large corporations are spending more on renewable energy. In fact, according to the Solar Industries Energy Association, Target is the largest corporate solar energy buyer, followed closely by Walmart and Apple. Apple’s share of the energy market could power 39 million iPhones every day for a year.
3. Solar Panels Can Convert Energy
You’ve probably seen a couple of solar panels, including the ones on your calculator. But what are solar panels? And how do solar panels work?
Solar Panels are created from two levels of silicon — a positive layer and a negative layer. These layers are filled with photovoltaic (PV) cells and create an electric field, similar to a battery. When the sun hits a solar panel, the PV cells absorb the light and use it to separate the photons from electrons, creating direct current (DC) electricity. However, this electricity is pretty useless as it cannot power anything in your home. Luckily, solar panels also come equipped with an inverter that converts the DC electricity into alternating current (AC) electricity. The AC electricity runs through your net meter and powers everything within your home. Your leftover energy is donated to the power grid and saved for future uses (like once the sun goes down).
4. Solar Energy Isn’t Afraid of the Dark
Because solar panels are powered directly by the sun, the techniques don’t work at nighttime. The PV cells can only absorb sunlight and cannot separate the photons without it. So does your electricity shut off when the sun goes down?
Luckily, solar energy offers two options for night owls. First, your solar panels can go into standby mode until the morning. For the rest of the night, your power will be drawn from the utility grid. This option also works on cloudy days when solar energy is not prevalent enough to power all your electricity.
The second option is solar batteries. These batteries, usually included with solar panel installation, store energy from the sun throughout the day and act like a generator at night. This means that the excess energy created throughout the day is stored for your personal usage, instead of being sent back to the grid. While you might still rely on the grid once the battery is depleted, having this additional security can grant more control over energy finances. They also ensure that your house remains up and running in the case of a grid malfunction.
5. Solar Energy Has Been Around Forever
Harnessing energy from the sun is not a new concept. In fact, solar energy has been used for over 2,700 years. In 700 B.C., it was discovered that fire could be sparked by using a glass lens to magnify the sun’s rays. Even the Greeks and Romans understood the power of the sun and built their homes with south-facing windows so the sun could light and heat their rooms. In 1954, the first silicon solar cell was built by Bell Labs and became the precursor for the solar panels used today. In modern times, solar panels are built to last. Current panels can last between 40 and 50 years, and lifespan improvements are constant.
The future for solar energy seems brighter than the sun. By providing 24/7 power from a renewable resource at a fraction of the cost of other providers, solar energy is truly here to stay. These fascinating facts only touch on some of the amazing qualities of the sun’s energy and over the course of the next decade, there can only be more improvements and discoveries.