Solar Power

The Sun The Sun’s surface is called the photosphere is 10,000 Fahrenheit.  The temperature at the core, or very middle, of the Sun, is about 27 million Fahrenheit. The sun is only important to our solar system. There are over 100 billion stars in the milky way.

The Sun Is a G2 dwarf star that is 4.6 billion years old It will burn for another 4.6 billion years The sun is only important to our solar system. There are over 100 billion stars in the milky way.

The Sun The sun is the closest star to Earth and is 149.60 million kilometers (92.96 million miles) away The sun rotates on its axis once every 25.38 Earth days or 609.12 hours The sun is only important to our solar system. There are over 100 billion stars in the milky way.

The Sun Approximately 109 planet Earths would fit on the surface of the sun More than one million planet Earths would fit inside of the sun. The sun is only important to our solar system. There are over 100 billion stars in the milky way.

The Sun 100,000,000,000 tons of dynamite would have to be detonated every second to match the energy produced by the sun The sun is only important to our solar system. There are over 100 billion stars in the milky way.

The Sun

How could we utilize the Sun? The sun is a renewable energy resource. Just a tiny fraction of the Sun's energy that hits the Earth (around a hundredth of a millionth of a percent) is enough to meet all our power needs many times over. In fact, every minute, enough energy arrives at the Earth to meet our demands for a whole year if only we could harness it properly.

Solar Green House Sun’s short waves go in Infrared rays cannot get back out Warm air rises from the ground Air collectors heat the ambient air and circulate it around

Envelope Homes Utilizes convection Passive (no moving parts) Air collectors heat the ambient air and circulate it around

Envelope Homes Trombe Walls Sun goes through glass and is absorbed by the absorber Air collectors heat the ambient air and circulate it around

Parabolic Dish Reflects rays of the sun to a focal point Hydronic collectors heat a fluid called a hydronic fluid and then used in heat exchangers or stored in tanks. Water can also be superheated into steam and create electricity.

Parabolic Trough Reflects rays of the sun to a focal point Hydronic collectors heat a fluid called a hydronic fluid and then used in heat exchangers or stored in tanks. Water can also be superheated into steam and create electricity.

Solar Hot Water Water is heated Stored in tanks Hydronic collectors heat a fluid called a hydronic fluid and then used in heat exchangers or stored in tanks. Water can also be superheated into steam and create electricity.

Photovoltaic Cells A solar electric system that converts visible sunlight directly into electricity Light hits a silicon or cadmium sulfide and creates a positive and negative charge. Cell acts as a small battery

Photovoltaic Cells

Connecting to the Grid

Solar Thermal Energy Conversion

What is it? Solar thermal electric energy generation concentrates the light from the sun to create heat, and that heat is used to run a heat engine, which turns a generator to make electricity. The working fluid that is heated by the concentrated sunlight can be a liquid or a gas. Different working fluids include water, oil, salts, air, nitrogen, helium, etc.

What is it? Different engine types include steam engines, gas turbines, Stirling engines, etc. All of these engines can be quite efficient, often between 30% and 40%, and are capable of producing 10’s to 100’s of megawatts of power. Heat can be stored during the day and then converted into electricity at night.

Major Solar Thermal Industry Players eSolar http://www.esolar.com/ Brightsource http://www.brightsourceenergy.com/ Abengoa http://www.abengoasolar.com/corp/web/en/index.html

2 types of Solar Thermal Collection Line Focus Point Focus

Line Focus Less Expensive Technically less difficult Not as efficient 250° C or 482° F

Point Focus Series of mirrors surrounding a central tower. 500° C or 932° F

Point Focus

Point Focus

References c “Solar System Exploration: Sun.” NASA.gov. June 11, 2008. Accessed: June 10, 2009. d “Sun: The Center of It All.” NationalGeographic.com. Accessed: June 10, 2009. http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sun http://www.motherearthnews.com/Green-Homes/1979-03-01/The-Thermal-Envelope-Home.aspx http://www.builditsolar.com/Projects/SpaceHeating/SolarWall/SolarWall.htm