Most solar cells are made from which element?
AnswerSilicon
Silicon, a semiconductor refined from sand, is the main material in most solar cells.
Science · Facts & stats
Panel facts & stats
7 fact-checked facts about solar panels, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
In the Northern Hemisphere, which direction do fixed solar panels usually face?
AnswerSouth
At most Northern Hemisphere latitudes the Sun crosses the southern sky, so south-facing panels catch the most light.
Going deeper
What device converts a solar panel's electricity into the form used by household wiring?
AnswerInverter
An inverter is the device that changes a solar panel's output into the type of electricity that household appliances and the grid use.
Albert Einstein's Nobel Prize in Physics was awarded for explaining which effect?
AnswerThe photoelectric effect
Einstein's Nobel Prize recognized his explanation of how light knocks electrons out of materials.
What usually happens to a solar panel's efficiency as it gets hotter?
AnswerIt goes down
Solar cells lose voltage as temperature rises, so hot panels convert sunlight less efficiently.
Expert level
Who first observed the photovoltaic effect, in 1839?
AnswerEdmond Becquerel
French physicist Edmond Becquerel saw a current produced when light shone on electrodes in a solution in 1839.
What sunlight intensity is used in the standard test conditions for rating solar panels?
Answer1,000 W/m²
Panel ratings use standard test conditions of 1,000 W/m² irradiance at a 25°C cell temperature.
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