SOLAR ENERGY PROJECTS

SOLAR ELECTRICAL APPLICATION- 1876 - PHOTOELECTRIC DREAMS William Grylls Adams, who, with his student, Richard Evans Day, discovered in 1876 that a solid material - selenium - produced electricity when exposed to light. Today, we refer to electricity produced directly from light as the photovoltaic effect. When William Grylls Adams and his student, Richard Evans Day, discovered that an electrical current could be started in selenium solely by exposing it to light, they felt confident that they had discovered something completely new. Werner von Siemens, a contemporary whose reputation in the field of electricity ranked him alongside Thomas Edison, called the discovery "scientifically of the most far-reaching importance." This pioneering work portended quantum mechanics long before most chemists and physicist had accepted the reality of atoms. Although selenium solar cells failed to convert enough sunlight to power electrical equipment, they proved that a solid mate...

SOLAR THERMAL APP HISTORY- SOLAR HOT WATER HEATING A cross-section of a hot box. Eighteenth- and nineteenth-century scientists used the hot box to test how much sunheat glass-covered enclosures could trap. Horace de Saussure, a noted Swiss naturalist, observed in the 1760s, "It is a known fact, and a fact that has probably been known for a long time, that a room, a carriage, or any other place is hotter when the rays of the sun pass through glass. To determine the effectiveness of trapping heat with glass covers, de Saussure built a rectangular box out of half-inch pine, insulated the inside, and had the top covered with glass, and had two smaller boxes placed inside. When exposed to the sun, the bottom box heated to 228 degrees F (109 degrees C) or 16 degrees F (9 degrees C) above the boiling point of water. de Saussure was unsure of how the sun heated the glass boxes. Today we can better explain what happened. Sunshine penetrated the glass covers. The black inner lin...

What are Photovoltaic (PV) Panels? Photovoltaic Panels are are used to transform sunlight energy into electrical energy.  ”PV panel” is the common name for a photovoltaic panel.  Literally translated photovoltaic means "light-electricity". Photovoltaic means "light-electricity".  It is formed from photo- which means light and -voltaic which means electrical current or electricity. PV panels are made up of smaller sections called solar cells.  Solar cells, like batteries, each have a rated value of voltage (V or volts) and amperage (A or amps).  The total power in wattage (W or watts) delivered is the voltage times the amperage. Volts x Amps = Watts or V x A = W Batteries can be arranged in parallel or in series depending on the requirements of the device we want to power. Batteries in Parallel In parallel the amperage is additive and the voltage is constant.  If we have batteries that are 1.5 V each and 1.8 A each then: ...

CONCEPT--  What is Solar Energy? The Law of Conservation of Energy: Energy can only change from one form to another. Energy can not be created or destroyed. Solar Energy is the energy from the Sun.  The Sun is a big ball of heat and light resulting from nuclear fusion at its core.  The nuclear reaction releases energy that travels outward to the surface of the Sun.  Along the way to the surface the energy transforms so that by the time it is released it is primarily light energy.  Sunlight.  The two major types of solar energy that make it to Earth are heat and light. Solar energy is often called "alternative energy" to fossil fuel energy sources such as oil and coal. One example of our use of solar heat energy is for water heating systems.  A solar panel is used to collect heat.  The heat is transferred to pipes inside the solar panel and water is heated as it passes through the pipes.  The hot water, heated by t...

SUN THE FATHER OF SOLAR ENERGY- How energy we can consume from sun? The sun is a star.  It is the largest object in our solar system and one of the larger stars in our galaxy.  The source of energy in the Sun is at its core where hydrogen is converted to helium in a thermonuclear reaction.  This energy travels from the core to the surface of the Sun and is released into space primarily as light.  The energy that comes to the Earth is in 2 main forms, heat and light. Every hour, enough sunlight energy reaches the Earth to meet the world’s energy demand for a whole year. --- U.S. Department of Energy --- The amount of energy from the Sun that reaches the Earth annually is 4 x 10 18  Joules.*** 4 x 10 18  Joules/ Year ÷ 365 Days/ Year = 1 x 10 16  Joules/ Day 1 x 10 16  Joules/ Day ÷ 24 Hours/ Day = 4 x 10 14  Joules/ Hour The amount of energy consumed annually by the world's population is about 3 x 10 14  Joules. Spe...

HISTORY OF SOLAR ENERGY Solar energy has been used by humans for thousands of years.  For example, ancient cultures used energy from the sun to keep warm by starting fires with it.  They also kept their homes warm through passive solar energy designs.  Buildings were designed so that walls and floors collected solar heat during the day that was released at night to keep them warm.  If you have ever stood in the sun to get warm then you too have utilized solar thermal energy. The discovery of photovoltaics happened in 1839 when the French physicist Edmond Becquerel first showed photovoltaic activity.   Edmond had found that electrical current in certain materials could be increased when exposed to light.  66 years later, in 1905, we gained an understanding of Edmonds' work when the famous physicist Albert Einstein clearly described thephotoelectric effect, the principle on which photovoltaics are based. ...