Solar Energy | Powering the Third Rock from the Sun

Solar energy means sun-powered energy, and mankind has harnessed solar energy for a few thousand years. 

The sun is 93 million miles from Earth, but it’s the closest star. As a result, it provides life-giving power to Earth and every living thing on this rock.

How the Sun Powers the Earth

No, we haven’t been using solar panels for thousands of years; our ancestors simply realized the sun powers the growth of crops and has used that to their advantage for at least 10,000 years. As a result, agriculture has followed the cycles of the seasons, homes have been built to maximize sun exposure for heat, and technology has been developed to convert the sun’s energy for multiple uses.

solar energy
Image by Sebastian Ganso from Pixabay

Types of Solar Energy

There are three general types of solar energy.

  • Photovoltaic

This is electricity created by the sun. Photons (sunlight) shine from the sun and can be collected via solar panels on Earth. The photovoltaic cells on a solar panel convert photons into the type of power we need to for electronics. Remember being amazed by your grade-school calculator that turned on when you put it on your desk, but wouldn’t work when tucked in your bag or a drawer? That’s thanks to the little solar panels located on the face of the calculator to harness photons and turn them into power.

  • Thermal

This is just a fancy word for heat. The sun’s photons also provide thermal energy. This can be converted into electricity via a generator.

  • Passive Thermal Energy

Without the conversion process, you have passive thermal energy. No work is needed to be warmed by the sun, but you can amplify the heat with a greenhouse, or a structure that implements solar architecture to maximize the heat provided by the sun.

Throughout history, homes have been built to face the South in order to harness the heat and light offered by the sun. Other early evidence of using solar energy can be found in greenhouse structures, which convert sunlight into heat for plants. It’s believed that Roman emperor Tiberius loved cucumbers so much he had a greenhouse constructed around 30 CE (common era) to allow the plants to grow year-round. Although glass hadn’t yet been invented, Tiberius’ greenhouse was made with thin sheets of mica, which is a semi-translucent mineral.

solar energy
Image by Jude Joshua from Pixabay

The Evolution of Solar Energy

Throughout history, mankind has studied how the sun affects the Earth. The sun does more than just help you grow a beautiful lawn! From photons and photosynthesis to gravitational pull and greenhouse gases, there’s a lot to discover.

  • 7th Century B.C. – Humans allegedly concentrate sunlight through magnifying lenses to start fires
  • 3rd Century B.C. – Greeks and Romans use mirrors to harness solar power for lighting torches
  • 1200s A.D. – Pueblo/Anasazi homes are built into cliffs facing the sun to create “sunrooms” where they can stay warm during winter
  • 1767 – Swiss physicist Horace de Saussure is credited with building the first solar box cooker
  • 1800s – Solar water heaters are introduced 
  • 1873 – Willoughby Smith discovers that the element selenium can conduct photon energy
  • 1876 – William Grylls Adams and Richard Day Evans further develop Smith’s research and discover that selenium can create electricity when exposed to sunlight
  • 1883 – Solar cells are introduced by Charles Fritts using selenium wafers
  • 1954 – The first photovoltaic cell made from silicon is invented at Bell Laboratories
  • 1958 – Solar cells are used on the Vanguard I satellite launched from America
  • 1973 – Solar One is constructed by the University of Delaware, claiming the title of being the first solar building to use integrated photovoltaics for energy
  • 1976 – U.S. President Jimmy Carter has solar panels installed on the White House (later removed in 1981 by President Ronald Reagan)
  • 1980s – Solar disinfection (SODIS) is used to make potable water
  • 1981 – The first solar-powered airplane is built by Paul MacCready
  • 2001 – NASA sends a non-rocket aircraft 96,000 feet up into the atmosphere using solar power
  • 2009 -Taiwan builds the Kaohsiung World Stadium with 8,800 solar panels on the roof, which not only powers the stadium for games but 80% of the neighborhood around it
  • 2010 – President Barack Obama has solar panels and a solar water heater installed at the White House.

Pros of Solar Energy

Since the sun shines everywhere, it’s a universal power source. Here are some more specific benefits of solar energy.

  • Reduces Pollution

Unlike other power sources, solar panels do not release carbon dioxide, nitrous oxide, methane, or any other pollutants to the air or water.

  • Long Lifespan

Have you ever marveled at solar panels installed on rooftops? How do they withstand harsh weather? Thanks to lots of research and advancements in construction, modern solar panels are built to not only withstand wind and rain but hailstones up to one inch in diameter. Their long lifespan makes them a worthwhile investment for residences and businesses interested in solar power.

  • Renewable

Hopefully, we’ll never run out of sunlight. Unlike fossil fuels, there’s no finite amount of sunlight, meaning it’s a renewable resource we can use to create energy in our homes and businesses.

Cons of Solar Energy

Solar energy isn’t for everyone, and that’s okay.

  • It is Intermittent 

Obviously, there’s no sun at night. Solar cells can only harness solar energy during daylight hours, which means solar may best be used as a supplement energy source rather than a primary one.

  • It Takes up Space

The technology needed to collect solar energy needs physical space. It can not only be cumbersome, but it can disrupt natural habitats when installed. Additionally, solar panels aren’t the most aesthetically pleasing addition to your roof or yard.

  • It’s Expensive

The cost of harnessing and storing solar energy is pretty high. Advances in solar tech are working toward being more efficient and less expensive, but it’s still going to cost more to install than typical power sources. For comparison:

  • 1956 – Solar panels cost an estimated $300 per watt
  • 1975 – Solar panels cost an estimated $100 per watt
  • 2021 – Solar panels cost an estimated $0.50 per watt


Do your research to see how you can make use of solar energy in your home or business. Perhaps you’re considering building a new home, and you want to ensure certain rooms take advantage of sunlight throughout the day. Or maybe you’re going to build a garden and want to position a greenhouse in the optimal spot for heat and light. If you want to cut energy costs, solar panels on your roof may do the trick. Whatever the reason, it’s worth looking into this environmentally-friendly source of energy.

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