The use of pollution-free direct sunlight probably has the greatest potential of all the forms of solar energy for becoming a major source of energy in the future

• But today it is not yet used in any major way.

Each year the Earth receives from the sun about ten times the energy that is stored in all of its fossil fuel and uranium reserves put together. 

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Direct sunlight can be used to heat space and water.

• It can also produce electricity ....

• indirectly in solar thermal systems

• directly by using photovoltaic or solar cells.

A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity

The photovoltaic effect is a physical and chemical phenomenon.

Solar thermal systems collect sunlight through mirrors or lenses and uses it to heat a fluid up to high temperatures.

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The fluid heats water to produce steam, which is then used to drive turbines to generate electricity. 

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The Cost?

The cost of solar has dropped significantly in the past several years. A decade ago, an average 6 kilowatt hour residential solar system could cost more than $50,000.

Now, the outright cost of a typical home installation ranges from $16,200 to $21,400, which is a 62% average annual decrease.

Although dropping in cost, solar cells are still relatively expensive

• Solar power, overall, in 2009 was far more expensive than energy produced from oil, natural gas, coal, and even wind.

• The high cost of solar cells is probably the most serious hindrance to their wider use

Riding the Light

What countries are investing into Solar Energy

In 2019, China produced the most solar cells in the world

Top 7 Countries That Use Solar Energy

• China: 204,700 MW (32.6%)

• United States: 75,900 MW (12.1%)

• Japan: 63,000 MW (10.0%)

• Germany: 49,200 MW (7.8%)

• India: 42,800 MW (6.8%)

• Italy: 20,800 MW (3.3%)

• United Kingdom: 13,300 MW (2.1%)

Oh, how things have changed.

• The United States was once the world's leader in solar energy but the ending of governmental incentives after the 1980s and low natural gas prices ended its leadership.

• In 2005 solar power was mainly used in the United States to heat swimming pools

The Middle East

Some regions, such as parts of the Middle East and North Africa, are particularly well suited for large-scale solar thermal plants, and these plants are becoming cost competitive. 

Developing Nations to the Rescue?

The developing world is in fact, often mentioned as a vast potential market for solar energy because many of its rural areas still lack electricity.

Solar energy could be used well in moderately or intensely sunny places. 

• Much of the developing world fits this criterion

In conclusion

If one includes the hidden costs of fossil fuels. That is, the costs society bears now and will bear in the future because of the pollution produced and the costs of military forces to ensure access to fossil fuels, then one can may come to the conclusion that....

Solar energy is probably less expensive than fossil fuels right now.