The earliest recorded use of solar energy by humans was in the 7th century BC when the magnifying glass was used to light fire. Later, in the 3rd century BC, Greeks and Romans harnessed solar energy to light torches for religious ceremonies using mirrors.
The “sunrooms” in Roman bathhouses and much later the solar-powered ovens and steamboats of the 18th and 19th centuries stand testimony to our association with this abundant and free natural resource.
Despite our ability and know-how to harness the sun’s power for centuries, it was only in the mid-20th century that solar panels as we know them today were invented. As a result of the collective effort of scientists from the late 19th century, the photovoltaic (PV) cell was created with silicon at Bell Labs in 1954.
Here are some amazing, interesting, surprising, and fun facts about solar energy and solar panels.
Some awe-inspiring facts about solar radiation
Solar radiation, also known as a solar resource or just sunlight is the primary source of energy for life on the earth and by a long way. Every single part of the earth’s surface receives sunlight at least for some part of the year.
- As a result of nuclear fusion happening in its core, the sun releases an incredible amount of energy as heat and light particles called protons. Electromagnetic solar radiation is released into space.
- Sunlight is a portion of this radiation that reaches the surface of the earth and is known as insolation.
- Sunlight takes 8 minutes and 20 seconds to travel from the surface of the sun to the earth at its closest point. The distance traveled by the sunlight is 91 million miles or 147 million kilometers.
- One hour of sunlight reaching the earth’s surface is sufficient to meet the energy needs of the entire world for a year.
- The earth’s upper atmosphere receives 174,000 terawatts of solar insolation constantly. About 30% of insolation is reflected into space and the rest is absorbed by clouds, water bodies, and landmasses.
- The water cycle is an important consequence of solar insolation. The heat energy from the insolation is absorbed by oceans resulting in evaporation. The water vapor rises to higher altitudes forming clouds that cause rain.
- Another positive result of solar insolation is photosynthesis. The plants convert solar energy into chemical energy, thus creating biomass, another renewable energy resource.
Amazing facts about solar power
The sun doesn’t merely provide us with light and warmth. It is also a source of energy. Solar power is the energy generated from sunlight using a process known as the photovoltaic effect. A photovoltaic cell converts the sun’s energy into electricity. The protons present in the sunlight knock out the electrons in the atoms on the surface of a photovoltaic cell, making them flow in a particular fashion. The flow of electrons constitutes electricity.
- Solar energy is a clean, renewable, sustainable, and green energy resource.
- Solar energy is the least polluting resource for generating electricity.
- Solar energy is the cheapest and most abundant energy source for us on the earth.
- Solar energy is cheaper than energy generated from fossil fuels.
- Solar energy is measured in kilowatt-hour. One kilowatt-hour is the electricity required to power a 1kW appliance for an hour.
- It is possible to power homes and offices 24 hours a day, 7 days a week solely on solar energy.
- The oil crisis of 1970 acted as a catalyst for the solar industry. It revealed the danger of our dependence on fossil fuels for power generation. The devastating incident opened up a massive search for renewable energy resources. This research helped in making solar energy affordable and convenient.
- Airplanes can fly around the world powered entirely by solar energy. The first aircraft built to run on solar energy, the Solar Challenger was built by Paul MacCready in 1981. He used it to cross the English Channel. The Solar Impulse 2, the world’s most powerful solar-powered aircraft was flown by Bertrand Piccard for a trip around the world in 2016.
- One of the earlier applications of solar energy was to provide power to satellites in outer space. Vanguard I satellite was the first one to use a one-watt solar panel to play the radio. The first Nimbus satellite launched by NASA in 1964 was the first satellite to run entirely on solar energy.
- The University of Delaware constructed the first solar-powered building Solar One in 1973. It used a hybrid of solar thermal and solar PV power integrated into the rooftops instead of an arrangement of solar panels. This is similar to the latest Tesla Solar Roof.
Fantastic facts about solar power plants
A solar power plant converts the solar energy into electricity using the photovoltaic process (PV) or Concentrated Solar Power (CSP). The CSP systems involve the use of mirrors, lens, and tracking systems to converge a large amount of sunlight to a small beam.
- China has been the world leader in solar power generation since 2015.
- The United States is the second-largest solar power generator and solar energy market in the world.
- California is the solar capital of the United States. The Ivanpah solar facility in the Mojave Desert is the largest solar plant in the United States.
- Solar energy consumers help in avoiding greenhouse gas emissions of 35 tons of carbon dioxide each year. In 30 years, rooftop solar power systems alone will be able to reduce pollution by 100 tons of carbon dioxide.
- 75 million barrels of oil are saved each year by solar power.
- Among the world’s top solar power stations, four are in India and three in China.
- The world’s largest solar park as of 2020 is located in Bhadla, India. Bhadla Solar Park is spread over a total area of 5,700 hectares (14,000 acres) and has a capacity of 2,245 MW.
- Huanghe Hydropower’s Golmud Solar park located in Qinghai province, China comes a close second with a 2.2 GW generation capacity and is backed by 202.8 MW/MWh of storage capacity.
- The lifespan of solar power plants is approximately 40 years.
- The solar PV industry employs 3.75 million people directly as of 2019.
History of solar panels
A solar module is an array of solar cells interconnected electrically in a series or parallel circuits to produce a higher power output. The arrangement of PV cells is sealed in a protective laminate to shield it from the vagaries of nature. The photovoltaic modules form the basic building blocks of a solar system.
- In 1839, at the age of 19 years, Alexandre Becquerel stumbled upon the photovoltaic effect, while working in his father’s laboratory. He created the world’s first photovoltaic cell with two electrodes coated with silver chloride or silver bromide immersed in an acidic solution and separated by a thin membrane. By illuminating one of the electrodes, he observed significant production of electricity.
- In 1883, Charles Fritts, an American inventor, built the first solar cell by coating selenium with a thin layer of gold. The conservation rate of this cell was in the range of 1-2%. This is very low when compared to the efficiency level of 15-20% in modern solar cells.
- In 1941, Russell Ohl, an American engineer, created the first silicon photovoltaic cell. While working in Bell Labs to improve the capabilities of radio broadcasting, accidentally discovered the p-n junction, which is the fundamental principle behind modern silicon solar cells.
- Gerald Pearson, Calvin Fuller, and David Chapin, the American researchers at Bell Laboratories, improved on Ohl’s silicon solar cell and developed the first modern solar cell in 1954. It had an efficiency level of 6%. Later in 1960, they improved the conversion efficiency to 14%.
- The era of the low-cost solar cell was made possible by Dr. Elliot Berman with funding from Exxon in the early 1970s. Dr. Berman brought down the price of solar energy from $100 per watt to $20 per watt. He discovered that instead of using a single silicon crystal, combining multiple silicon crystals is cheaper, though it marginally reduced the efficiency of the solar cell.
In 1979, solar panels were installed on the roof of the White House by President Jimmy Carter. The panels were removed in 1986 on President Reagan’s orders. President George.W.Bush had new panels installed in 2003. More were added by President Obama for generating 19,700 kilowatt-hours of electricity a year.
Awesome facts about residential solar power systems
Embracing solar energy by the common man faces many hurdles. The most prominent being the cost factor and the extra effort required for installation. Even though the cost of solar panels has come down substantially since the 1970s, especially in the last decade, there is still hesitancy in adopting clean energy technology.
Another stumbling block is the inconvenience of having solar panels spread out across the rooftops or yards and the maintenance, though limited, it requires. Solar power systems will become more common when it equals the convenience of grid energy.
- Solar power is the fastest energy production to set up.
- Solar panels can generate 10 kilowatt-hours of electricity per square foot.
- 191,000 square miles of solar panels are required to meet the global power demand.
- Residential solar systems pay for themselves in 7-8 years. If the conditions are perfect for solar production, it is possible to break even in as early as three years.
- Solar panels can produce electricity even with indirect sunlight.
- Solar panels are almost maintenance-free as they do not have moving parts.
- Solar panels made with monocrystalline silicon have the highest efficiency levels.
- The average efficiency of home solar panels is 20%. This means it converts 20% of sunlight received by it into electricity.
- The average lifespan of a solar panel system is 20-25 years.
- Home solar systems typically come with a 25-year warranty.
- The cost of solar panels has come down by 99% since the 1970s.
- The United States is home to more than 2 million solar energy systems.
- The cost of solar panel installation is less than $3 per watt in some U.S. states.
- With the rising popularity of solar energy, there are choices available for homeowners to enjoy the benefits of solar power without physically installing solar panels.
Now, it is all the more attractive to switch to solar power because of the financial incentives available for residential and commercial solar installations. This is in addition to the reduction in electricity bill. However, for true-blue environmentalists, what matters the most is the good solar installations can do in our fight against climate change.