1. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Photovoltaic Panels for the Inquisitive

2. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Solar Collection vs Solar Transference Radiant Convection Thermo Transference of radiant heat energy into liquids or gases Solar Hot water – transfer of radiation into water Solar heater – transfer of radiation into air mass e.g. your car on a hot day Radiant Transference Radiation (light energy in the form of photons) transferring kinetic energy into another kinetic energy i.e. electrical Solar PV – the ‘exciting’ of electrons by sunlight The Sun as kinetic energy? Source: Solar Hot Water TAFE Resource Module

3. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Solar Collection vs Solar Transference Energy Forms Radiation = kinetic energy The sun has a thermonuclear (fusion) interior – ‘energy’ transferred from here High energy radiation (gamma rays) released through photosphere via convection Chromo sphere transmits solar flares (thermal gases that make it past the gravitational pull) into the corona – solar wind Solar wind is essentially electromagnetic radiation – waves of photons This radiation filtered by earth’s atmosphere – particularly Ozone (O 2 supercharged with an extra oxygen atom to form a allotrope) – 1/200,000,000 of original ‘potential work” 270 trillion KWs ‘potential work’ at the earth’s surface (1000 watts per square meter) The Sun as kinetic energy? Kinetic (energy in motion) Electrical – atoms Radiant- solar Thermal Motion Sound Potential (stored energy) Chemical (e.g. coal) Mechanical (e.g. rubber band) Nuclear Gravity

4. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Solar Collection vs Solar Production Distributing factors on Solar Radiation Sunshine hours Is the sun (radiant energy) received on the earth’s surface on a bright, clear and cold day Two forms are – direct beam and diffused beams Direct beans are needed for energy production (Solar Panels – radiant heat used to create further kinetic energy) but both can be used for solar convection (solar hot water – heat used to create potential energy) Maximum benefit for sunshine hour capture is at true north – true solar noon (when the sun shadow lies directly on the North South longitude line) Most beneficial tilt to sun is at 38 0 – average over seasons/months and Azimuth The Sun as potential and kinetic energy? Source: Solar Hot Water TAFE Resource Module

5. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Photovoltaic Panels – Made from Silicon Crystals Silicon as an insulator and semi conductor Silicon Valley – the semiconductor and IT When photon/radiation falls on silicon – the element absorbs some of the photons and converts them to electrons. More Importantly the ‘photo’ response by the atoms is to release electrons that then look for a new bond Silicon crystal atom structure has a strong nucleus but weaker outer shell (4 electrons but it wants 8….) Using Crystals Carbon Crystals are usually called ?. Silicon crystals create a strong a semiconductor having four electrons in their electron structure thus creating a lattice. Good insulator as free electrons cannot move around – think of your toaster Metal is a good conductor as electrons can move freely PVs – how do they work?

6. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Photovoltaic Panels Doping the crystals By making impure crystals this lattice is broken This is done by doping or adding another element such as Boron (3 electrons/ 1hole in the outer shell) or Phosphorus (5 electrons/1 extra in outer shell) – hence breaks up the lattice This creates a N-type or P- type cell in which electrons behave in a attracting (looking for the bond) or a repelling (looking for a hole) manner These crystals are layered a N-type against a P-type Photo responses by electrons As light (radiant energy or photons) hits the crystal – electrons are set in motion by looking for a new bonds Free electrons and holes pass through the lattice from the N-type side of the panel to the P- Type side and back PVs – how do they work? Boron – P-Type Phosphorus – N Type Electrons -ve

7. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au

8. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Photovoltaic Panels Current This transference of electrons between the layers creates a current A conductor (diode and cathode) are placed in each layer of the crystal – drawing off the current PVs – an application to AC from DC and why do we need inverters? Current produced by panels is Direct Current or DC PV’s straight to batteries are good – batteries work on DC Most of our appliances work on Alternating Current AC so better for PV electricity to go back into the grid directly Though inverters can change DC into AC by modifying and stacking square sine waves to Imitate curved sine waves PV’s also produce current at 12 volts hence an inverter changes the current from 12 volts into usable current at 240 volts PVs – how do they work?

9. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Photovoltaic Panels The angle of the dangle To optimize solar hours For Victoria 38 o from horizontal maximizes sunshine hours (isolation and Peak Sun Hours) To determine how many sun shine hours for your area, look in: The Australian Solar Atlas BoM – Daily Global Solar Exposure (www.bom.gov.au) PVs – how do they work? Sun Altitude at midday (from horizon) Known as Zenith Summer 90 o Equinox 75 o Winter 52 o Source: Solar Hot Water TAFE Resource Module

10. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au

11. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Solar SETS software

12. Developed in partnership with: © Planet Savers & CERES Solar SETS Educational Resources www.solarsets.com.au Solar SETS software