February 8, 2018 Solar Energy Written by Sara Popescu Slavikova
Facts about solar energy
Sun, the star of our universe,

the life and light giver. Without the heat and energy of the Sun, life on Earth would not be possible. Without its gravity, our solar system would not hold together. The Sun affects ocean currents, weather, changes of the seasons, climate, and even our mood.

On sunny days, our bodies produce more serotonin, a chemical that cheers us up and motivates us [1]. We are “programmed” to feel happy about the Sun. Even numerous civilizations in the past have worshiped the Sun as if they have always known how important this shinny star is for our lives. No wonder some of the greatest minds of our history expressed their beliefs of the tremendous potential of harvesting solar energy.

One of them was the highly progressive renaissance painter and inventor Leonardo da Vinci, who designed a plan of an industrial use of concentrated solar power to heat water. In 15th century! Five centuries before we have ventured into large-scale utilization of this renewable energy source.

Other brilliant minds, who believed in the inexhaustible solar energy include names such as Thomas Alva Edison, Werner von Siemens and Albert Einstein, also called the father of photovoltaics. What is less known is that Einstein actually won the 1921 Nobel Prize in Physics for his explanation of the photoelectric effect – not the theory of relativity [2].

“I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that.”

Thomas Alva Edison

So, while in the past decades it required the thinking of a genius to conceptualize the idea of powering houses with sunlight, today, it has become one of the most exciting technologies used globally. You might see new solar farms or photovoltaic arrays appearing in your neighborhood often. Next time you lay your eyes on them, think of these ten interesting facts you have learned from this article.


10 interesting facts about solar energy


#1 China dominates the solar energy production

China is the world’s leading solar producer. At the end of 2016, the country’s solar capacity reached 77.42 gigawatts, which was more than double of the United States production [3]. But the ambitious plans do not end here. By 2020, China intents to achieve in total at least 200 gigawatts of solar capacity [11].

This move to harness renewable energy was partly prompted by the fact that China’s air pollution makes it almost impossible for citizens to breathe clean air in cities like Shanghai and Beijing. According to statistics, heavy air pollution from coal power plants has led to the premature deaths of more than 1 million people in 2012 [4]. That is why, the country has now seized the chance on the pollution-free solar technology.

Particularly in the last couple years, some of the extraordinary Chinese projects made worldwide news. These include the 250-acre solar farm shaped like a panda bear; the mega photovoltaic installations in the Gobi Desert; the construction of the Solar Valley in Shandong Province – a heavily polluted area from the coal mining industry; or one kilometer of solar paneled highway in Jinan.


#2 Solar power is cheaper than you would expect

Solar power is increasingly affordable. The cost of solar panels has dropped by 80% since 2008, and it is expected to keep falling. It is predicted that the price of commercially-available solar technology will decrease by 4.4 percent every year, meaning that by 2022 the price will decrease by another 27 percent compared to today’s prices.

Currently, most homeowners in the United States are paying on average $3.50 per watt to install solar in their homes. In 2010, the cost was roughly the double (around $7.24).

If you are interested in knowing more, read about How Much Do Solar Installations Cost.

When considering the global reach, according to this study, falling costs of solar energy will most likely boost the deployment of this technology. In the ideal scenario, photovoltaic systems could supply up to 69 percent of the world’s electricity production by 2050.

At this point, renewable energy will become more cost-effective than fossil fuels combined together with nuclear power. This means that in the close future we could rely entirely on renewable energy.

#3 Photovoltaic systems save lives of endangered wildlife

Investing in solar energy is not only good for your finance, but also good for the environment. One of the most important environmental benefits is the reduction of air pollution and greenhouse gas emissions.

According to a fact sheet of the National Renewable Energy Laboratory (NREL), a standard, single-household photovoltaic system can reduce pollution by:

    • half a ton of sulphur dioxide,
    • half a ton of nitrogen oxides,
    • 100 tons (!) of carbon dioxide [5].

Such high numbers are significant for mitigation of climate change. Through our transition to solar power and reduction of emissions, we can help lower environmental threats for many climate-vulnerable species. These range from the top predators like polar bears, tigers, all the way to rhinos, elephants, caribou, whales, or even the whole complex ecosystems of coral reefs.

Two polar bear cubs playing

Two polar bear cubs playing


#4 The exciting invention of a Power Photocell

In 1883, American inventor Charles Fritts created the first photovoltaic module by spreading a thin layer of selenium onto a metal plate and covering it with a semitransparent film made of gold. His module was only 1 percent efficient, but produced a continuous current when exposed to sunlight. In the eyes of the scientific world, the invention was a great breakthrough.

Werner von Siemens, a colleague of Fritts, stated about the discovery: “[this module] presented to us, for the first time, the direct conversion of the energy of light into electrical energy [6].”

Less than a century later, in 1954, the first commercially-viable photovoltaic solar cell was invented. Charles Fritts unfortunately did not get to witness this discovery that was built upon his foundation.

The new solar cell used a newly tested semiconducting element – silicon. Because of the use of silicon, this solar cell was able to produce more power than any design could achieve before. This cell reached six percent efficiency and raised a high level of enthusiasm between scientists, calling it a “power photocell.”

The reaction of the press was equally excited, claiming that we might have just entered a new era of powering our lives with energy of the sun [6].

#5 A material better than silicon (?)

Silicon photovoltaic cells utilized in commercial solar systems have currently the highest efficiency, spanning from 15 to 22 percent. Monocrystalline and polycrystalline silicon solar panels make up 94 percent of the solar market.  But soon that might change…with perovskite.

According to scientists, perovskite solar cells could one day reach higher efficiencies than silicon cells. Perovskite’s maximum efficiency potential is yet to be discovered, but in the laboratory conditions, these cells already reach the same efficiency as silicon. So, it is likely that in the future, this material might break new efficiency records [7].

According to the National Renewable Energy Laboratory (NREL), perovskite could stand at the beginning of the large-scale deployment of solar energy in the future [8].

Unlike silicon, the manufacture of perovskite is much cheaper. It can be made from commonly used metals and industrial chemicals. Another advantage of this material is flexibility. The perovskite solar cells can be easily utilized in the thin-film technology.

Thin-film cells can be attached on structurally diverse surfaces such as house facades, and do not have to be rigidly mounted like traditional silicon panels.

#6 Solar energy provides more jobs than fossil fuel industry

“Today’s energy jobs are in solar, not coal.” – The New York Times.

“Solar employs more people in U.S. electricity generation than oil, coal and gas combined.” – Independent, Forbes.

These headlines appeared after the release of the US Department of Energy’s 2017 report. The report delivered some unexpected news. More than 374,000 Americans worked in the solar industry in 2015, accounting for 43 percent of people employed by the Electric Power Generation sector. Fossil fuels on the other hand employed 187,117 people, representing only 22 percent.
United States

    • In 2016, one American out of 50 was employed in the solar industry.

    • California, Massachusetts and Texas are the States with the largest portion of solar jobs [9].


    • Solar photovoltaics is the largest renewable energy employer in the world. The technology provided job to almost 2.8 million people in 2015.

    • China, Japan and United States were the main solar job providers [10].

Employees of a solar company are setting up a solar panel array

Employees of a solar company are setting up a solar panel array


#7 You don’t need to own a house or land to have solar panels

Do you think this is a typo? It’s not. The statement is 100 percent correct, you can own solar panels but do not have to worry about their installation and placement.

Community solar projects, also called solar gardens, allow you to buy your share of solar energy even when you would normally not be able to because of living in an apartment building or not having enough space for a solar panel placement.

Community solar is either a common project of a community (apartment owners) or a third party (utility company) that decide to build a solar farm in your area. Once the farm is set up, you can buy some of the already installed solar panels and receive monthly credits from their production on your utility bill.

The idea of community solar was born in 2006 in Ellensburg, Washington and since then has become fairly popular throughout the United States. In 2017, more than 100 community projects produced around 108 megawatts of solar power in 26 States [12].

Similar projects have made their appearances even in some European countries. For example, in the capital of Bulgaria, Sofia, 117 apartment owners have joined together to install solar panels on the roof of their block building [13].

#8 Promising source of energy for developing countries

More than one billion people, or 17 percent of the planet’s population, live without reliable access to electricity. Despite all the development, this number has remained pretty much the same in the last 50 years, because grid extension has proven to be logistically difficult and expensive in some of the most remote corners of the world [14]. But now, thanks to the accessibility of solar energy, the future of many rural areas starts to look better.

The year 2015 marks the first great milestone of developing countries overtaking stronger economies in the investment into renewable energy. For example, Bangladesh holds prime in selling residential solar systems [15]. Even African countries such as Kenya, Uganda and Tanzania follow India’s example. Small solar systems bring electricity to many off-grid locations for the first time.

Solar power is a welcomed source for many rural families for being clean, easy to set up and reliable. Previously used kerosene lamps and candles have caused many house fires. Long-term breathing of kerosene fumes could also negatively affect health of family members – possibly leading to brain, heart or kidney damage [16].
The lion lights
Solar lights have become a tool for Maasai cattle herders to keep their livestock safe from lion attacks in a non-violent way. A teenage Maasai boy, Richard Turere, came up with this amazing and efficient solution on how to live in peace with these large predators.

He invented “Lion lights”- a series of flashing lights on poles around the cattle pen. The lights are powered from old car batteries, which are charged by solar panels during the day. This simple invention scares lions off because they think that herders with flashlights guard the cattle.

You can watch Richard’s 2013 TED talk:


#9 Solar desalination to prevent water insecurity

Beyond electricity production, heating or lion scarring, solar energy can also be used for making potable water from seawater. Many areas around the world face increasing shortages of freshwater supplies.

Cape Town in South Africa is one of the scariest examples that made news at the end of January 2018. Satellite images have shown that the water reservoir for 4 million city residents dramatically shrunk in size, and according to some estimates, the city could run dry sooner than expected. As a solution to such a crisis, the city prepares to launch a seawater desalination program [17].

While conventional desalination is an expensive and (fossil fuel) energy-demanding process, solar-powered desalination could be our great chance to expand our water supply at lower cost and emissions.

One startup from Israel has been working on off-grid and low-cost desalination technology that could provide up to 10,000 cubic meters of water per day (2.6 million gallons). Their plan is to offer this system to island communities, areas of humanitarian crises, or remote tourist resorts in arid countries.

To learn how does the solar desalination work, read Solar-Powered Water Desalination Plant.


#10 Organic solar cells exist

Yes, even solar cells can be organic. Solar industry is booming and scientists are looking for better options to replace traditionally used silicon cells with more environmentally-friendly, less costly and more efficient option. As some of them believe, one such opportunity can come in a form of semiconducting organic materials.

Organic solar cells could potentially become environmentally safe and easily available option for large-scale solar projects. The manufacture of these cells can be fast and easy, because their soft molecules can be simply printed as a thin-film “roll-up” solar panels [18].

However, this technology is still at the beginning and the major drawback is that creating an electric current in organic cells is more difficult. This affects their efficiency and long-term reliability.

But with such a rapid progress happening in the solar industry, we might see some astounding discoveries in the next few years with researchers finding the right combination of organic materials that will overcome this barrier.

Let’s get surprised, shall we? Perhaps it will be one of you – the passionate Greentumble readers – who will come up with some wonderful solar innovation in the future. Get inspired, for our future could be as bright as the sunshine.



[1] https://goo.gl/d56bB1
[2] https://goo.gl/x6M2Rw
[3] http://www.bbc.com/news/business-40341833
[4] http://www.wired.co.uk/article/china-climate-change-policy-solar-production
[5] https://www.nrel.gov/docs/fy04osti/35489.pdf
[6] https://goo.gl/MKKaJg
[7] https://goo.gl/H3XEck
[8] https://www.nrel.gov/pv/perovskite-solar-cells.html
[9] https://www.thesolarfoundation.org/national/
[10] https://goo.gl/fKjrex
[11] http://reneweconomy.com.au/china-heading-230gw-solar-2020/
[12] https://www.seia.org/initiatives/community-solar
[13] https://goo.gl/zGT243
[14] https://ensia.com/features/solar-energy-solutions-for-the-developing-world/
[15] https://goo.gl/atpzpp
[16] https://www.livestrong.com/article/188038-health-effects-of-kerosene-heaters/
[17] https://goo.gl/5y9UQN
[18] http://pubs.sciepub.com/rse/2/3/2/