Lighten up: 21 solar facts

June 21 is the summer solstice – the longest day of the year in terms of daylight. Here are 21 facts on solar energy, and why the industry is advancing at light speed.

1. More energy from the sun lands on the face of the earth in just one hour than the entire global population uses in one year.

We have all the solar power we could want. Plus, unlike fossil fuels, it’s renewable and will never run out – at least not for a few billion years.

2. The US Department of Energy estimated that 90 percent of the electricity used by the US could be generated from solar panels installed in abandoned industrial sites in our nation’s cities.

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3. Elon Musk projects that solar energy will become the world’s largest energy source by the year 2031.

He’s not alone. The International Energy Agency has also projected that it won’t be long before solar dominates global electricity production.

Musk, in addition to having founded Tesla and SpaceX, is a strong environmental advocate – he even served as an advisor to the White House and advocated for clean energy, before quitting his role after the announcement of the US pulling out of the Paris Agreement.

4. The Solar PV sector in South Africa creates 88 times more jobs than coal power, and 620 times more jobs than gas and nuclear.

5. Costs for utility-scale solar panels have dropped 85 percent since 2009.

With rapidly falling costs and new business models, solar panels are becoming an increasingly financially viable option for average Americans – increased popularity and demand helps to drive down costs as they become more common across the country.

6. The solar industry was responsible for creating one in every 50 jobs added in the US during 2016.

In fact, the US solar industry now employs more than double the number of people that the US coal mining industry does – and that number is growing every year.

7. The photovoltaic effect – which converts sunlight into electricity – was first observed by physicist Alexandre-Edmond Becquerel in 1839.

Much of the Becquerel family was populated by physicists – Alexandre-Edmond’s father, Antoine Cesar, and his other son, Henri, were both noted in their fields for various discoveries and inventions. However, the photovoltaic phenomenon was not fully articulated until 1873 by engineer, Willoughby Smith.

8. The first practical solar cell was unveiled in 1954 by Bell Laboratories in New Jersey – and converted solar energy at an efficiency of about 6 percent.

Three scientists at Bell Laboratories – Daryl Chapin, Calvin Fuller, and Gerald Pearson – were primarily responsible for engineering the original silicon solar cells. Chapin was originally focused on engineering solar cells made of selenium, but silicon was quickly found to be significantly more efficient.

9. The current record for solar panel efficiency, 26.6 percent, was set in March 2017 by Japanese scientists.

The panel still uses the same principles in the original silicon cell design pioneered by Bell Labs in the 1950s, with a few significant innovations to minimize the space where electrons can’t exist and allowed for the collection of a greater number of light particles from the sun (known as photons).

10. In 2016, an average of 31,000 solar panels was installed every hour worldwide.

By the end of 2016, the Solar Energy Industries Association reported that there were 1.3 million solar panel installations across the US alone.

11. According to one projection, the cost of solar panels is projected to continue falling at a rate of about 10 percent per year.

The rapid decline of solar costs in recent years now means it’s increasingly becoming financially competitive or cheaper to use than fossil fuels in more and more places around the world.

In South Africa, solar PV costs USD 0.05 per energy unit; the worldwide average cost is USD 0.08, which makes it highly competitive and often more affordable than other sources of power such as baseload coal, gas or nuclear.

12. Small-scale PV systems can be used with or without connection to a power grid.

They can provide power to houses and buildings for essential services such as lighting and charging electric appliances. They are already providing alternatives in rural settings to electricitiy from distribution lines connected to national transmission lines. Extending a national or regional grid to remote villages has often been an expensive solution to rural electrification. Solar PV (with or without battery storage) can also help significantly reduce fuel costs in existing mini-grids. Even when a connection to the existing network is available, if an uninterrupted supply is required, such as in health-care settings, solar PV systems with battery storage can be an economic solution.

Off-grid PV markets have seen particularly dynamic development in a wide range of African countries.

13. Cooler temperatures actually make solar panels process sunlight more efficiently than at hotter temperatures.

This is due to the way that the photovoltaic effect works. Normally, electrons at rest on the solar panel (low energy) are excited by photons from the sun (high energy), and the difference between their excited and rest energies is the potential difference that you get from a solar panel (i.e., the size of the electrical current you can generate). However, if the electrons have more energy at rest (meaning your solar panels are already hot), the difference between the rest energy and excited energy you can create is smaller, and the solar panels will produce less energy.

14. The renewable energy sector acccounted for about 61,000 jobs in Africa in 2015

Renewable energy technologies are more job intensive than fossil fuels – the global average is three to six time more than fossil fuels or nuclear for the same amount of energy generated.  These ratios are even higher in Africa. Thus the potential of renewable energy  to create direct employment is considerably higher than conventional sources like coal, gas or nuclear.

15. According to one estimate, the surface area we would need in order to power the entire globe with solar would only cover approximately the same amount of surface area as Spain.

The entire planet has a surface area of about 197,000,000 square miles, while Spain has just 195,000 square miles – or about 0.09 percent of the total surface. Spreading solar panels across the globe, rather than keeping them condensed in one area, makes it even more feasible.

16. Solar PV uses on average 15L of water to produce 1 MGWh of electricity

This compares to an average 681L for thermoelectric power (natural gas), 1,476L for oil and coal, and  2,120L for nuclear.

17. The first solar-powered car was unveiled in 1955 … but it was only 15 inches long.

Like Chapin’s initial experiments, the solar panels on the car used selenium rather than silicon. Although an adaptation into an actual commercially viable automobile has yet to materialize, advancements happening this century give us reason to believe that solar-powered cars will one day be available in the future.

18. Solar angle affects how much power is generated by a panel.

A panel produces the most electricity when the sun is directly perpendicular to it. Solar panels are often installed at a tilted angle in order to receive the most direct amount of sunlight throughout the day – and some advanced solar panels are even calibrated to turn and follow the sun across the sky.

19. Solar panels don’t require moving parts to operate.

This means that it requires much less maintenance than other traditional forms of energy generation, which do require moving parts.

20. A radical switch to renewable energy could bring 1.8 million more jobs in Africa by 2030.

An ambitious switch to renewable energy and greater energy efficiency is likely to lead to at least 9% more jobs in Africa than business as usual by 2030.

21. For each unit of electricity generated, solar energy produces 10 times less hazardous waste than coal and gas

The production of solar energy technologies generates limited e-waste. In comparison, conventional fossil fuel-based energy sources are responsible for outdoor air pollution, water contamination by chemicals, as well as environmental hazards such as crude oil spills.

Why Does This All Matter?

Well, the more people that switch to solar, the better – as clean energy increasingly replaces dirty fossil fuels, less and less carbon pollution goes into the atmosphere. Not only that, but the solar industry is booming. It is creating jobs at an extraordinary rate, and as solar energy keeps getting cheaper and cheaper, it becomes accessible to more and more people.

Solar energy is a big part of the renewable future, plain and simple.

More about the positive impact of shifting to renewable energy in Africa in these infographics.