ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How Solar Panels Get Sun Energy

Updated on February 5, 2019

The energy that reaches the Earth in the form of sunlight is immense - more than 12,000 times greater than the world's fuel consumption. The sunshine falling each year on the surface of roads in certain parts of the world, such as the US alone, contains twice as much energy as all the coal and oil used every year in the entire world.

But collecting and storing this abundant supply of free energy is difficult and expensive. The sun sheds its rays thinly over a vast area and its heat must be collected and concentrated before it can be used in homes or power plants.

In domestic hot-water systems that use the Sun's energy, solar collectors (panels) are mounted on roofs facing the Sun. They have glass or plastic panels behind which water circulates in pipes painted black to absorb maximum heat. The heated water is then pumped into the hot-water tank.

Photo-voltaic Solar Cells


Japan has more than 3 million solar panels on its roofs, and half the houses in Israel have them. They are popular in California, but cloudier Europe, which gets only half the sunshine of Israel or California, has far fewer. Only a fraction of energy collected in direct sunlight can be trapped on an overcast day.

Solar energy is also used to generate electricity. For direct uses of the Sun high temperatures are needed, and to achieve them, sunlight must be concentrated by focusing.

Mirrors, rather than lenses, are arranged in a semi-circle, reflecting the sunlight towards a concrete 'power tower'. The concentrated sunlight shines on a receiver at the top of the tower and heats a fluid which circulates through pipes. If the fluid is water, the high-pressure steam that is produced is used to drive electricity generators.

The largest power tower in the world is near Barstow, California, in the Mojave Desert, which has 300 days of sunshine a year. Its reflector covers 100 acres (40 hectares) and consists of 1818 mirrors in concentric circles focused on a boiler at the top of a tower that is 255ft (78m) high. Europe's largest solar energy plant is in France, at Themis in the western Pyrenees. Built in June 1981, it has a generating capacity of 2.5mW. Virtually every spacecraft and satellite has depended on solar cells for its electricity since the US satellite Vanguard in 1958. Solar cells exploit the discovery, made in 1887 by the German physicist Heinrich Hertz, that certain substances generate electricity when exposed to light-the-photo-voltaic effect.

Solar car
Solar car | Source

Cells are made from a thin layer of silicon placed next to an even thinner layer of silicon impregnated with boron, which alters the electrical behavior of the silicon. Light falling on the outer layer causes electrons to migrate into the silicon backing, creating a voltage between the two layers. A series of cells must be connected together so their output adds up to a usable amount. Although silicon is cheap - it is the basic constituent of sand and rock - converting it into the single crystals necessary for solar cells is expensive. And huge numbers of cells are usually needed.

The Solar Challenger, an airplane powered by 16,128 solar cells generating 2.5kW, crossed the English Channel in 1981. Solar cars carry batteries, but only to store solar energy for use when it is cloudy or when the car is climbing hills. Everyday applications of solar energy, like solar-powered watches and calculators, are widespread. Solar-heated swimming pools are also becoming popular.

The first solar-cell power station of significant size - with an output of 1mW - was completed near Victorville, California, in 1982. One of the largest solar-cell projects in Europe is on the island of Pellworm, off the West German coast, where 17,500 solar cells covering an area as big as two football pitches provide the electricity for the island's health spa.


This website uses cookies

As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

Show Details
HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
LoginThis is necessary to sign in to the HubPages Service.
Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
AkismetThis is used to detect comment spam. (Privacy Policy)
HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
MavenThis supports the Maven widget and search functionality. (Privacy Policy)
Google AdSenseThis is an ad network. (Privacy Policy)
Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
Index ExchangeThis is an ad network. (Privacy Policy)
SovrnThis is an ad network. (Privacy Policy)
Facebook AdsThis is an ad network. (Privacy Policy)
Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
AppNexusThis is an ad network. (Privacy Policy)
OpenxThis is an ad network. (Privacy Policy)
Rubicon ProjectThis is an ad network. (Privacy Policy)
TripleLiftThis is an ad network. (Privacy Policy)
Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
ClickscoThis is a data management platform studying reader behavior (Privacy Policy)