Photovoltaic Devices Solar Thermal Electric Power PlantPhotovoltaic effect recognized The first application of solar thermalIn 1839 followed by the first in 1767 known as ‘hot box’, later inphotovoltaic cell in 1883. 1891 the first solar thermal system was built.Converts energy from the sundirectly into electricity Generate electricity indirectly from the sun. Most commonly used - Solar Power Tower, Parabolic Trough.Used to power or rechargeportable devices and for Used in large electric powerresidential commercial use. production and for residential commercial use.
- Solar Panels are made upof a collection of solar cellsthat are then bonded to asheet of glass. It convertssunlight into electricitywhich can be usedimmediately or stored in abattery.- Solar Cell is made ofsemiconductors, like silicon,that has special materialproperties that allow thesun light that strikes a cellto be absorbed in thematerial.
Charge controller - Also known as charge regulator, monitors the batterys charge state. - Protect the battery from discharging, below its lowest acceptable voltage, to prevent damage by over discharge. - Protects against wrong connection of the battery and reverse voltage to the panel. - Stores the power generated by the solar Batteries modules during the day to be used during the night. - The type of battery used is Deep Cycle (Lead Acid) Maintenance Free type. - This battery is designed to be fully charged and discharged over and over again without causing damage.
DC-AC Inverter- DC-AC inverters are used to convert Direct Current (DC) fromthe battery into Alternating Current (AC) to run AC appliances.- Types of inverters available are Stand-alone inverters,Synchronous inverter and multi-function inverter Stand-alone Inverter Synchronous Inverter Multi-function Inverter
Heliostat ~ Mirrors which reflectsthe sun’s energy to the correct Central Receiver ~ Receivesspot on the tower. concentrated solar radiation and transform it to thermal power. 3 Molten Salt ~ Stores the suns 2 heat and release it 1 in a controlled manner for steady SOLAR POWER TOWER steam turbine power generation. 4 5 6Condenser ~ Condense exhauststeam from the steam turbine Turbine ~ Receives steam Storage Tanks ~ Stores fluid,and channels it back to steam from steam generator that one at high temperaturegenerator. turns the turbine blades to and one at low temperature. generate electricity.
Collector ~ Structure of collector must :- Supports the mirrors and receivers,maintaining them in optical alignment- Withstands external forces(winds).- Allows the collector to rotate, so the 2mirrors and receiver can track the sun. 1 Mirrors ~ Usually coated with silver or polished aluminum. 6 Reflects the suns energy to the receiver. PARABOLIC TROUGH 3Collector Interconnect ~Connects the receivers on twoadjacent collectors and allows 4them to track independently. Steel tube ~Surrounded Drive ~ Positions the by a glass envelope to 5 collector to track the reduce convection heat sun during the day. It losses. Functions as a can be either a standard Fluid ~ Normally receiver that can motor and gear box oil, absorbs accept optical input configuration or can use sunlight, increases from any direction. a hydraulic drive System. temperature and heats steam in
Multiple solar or The solar cells willConverts energy photovoltaic cells convert sunlight from the sun are connected to directly into into electricity. form a solar electricity (DC). module. It monitors the The role of the charge The electricity condition of the controller is to from the solarbattery state of charge regulate the voltage cells is stored and protects the and current from the in the battery battery from being solar cells before it is for immediate over-charged. stored in the battery. or later . The charge controller will also protect the Where required, an inverter battery from is used to change the Direct discharging below its Current (DC) to Alternating lowest acceptable Current (AC) to power most voltage. AC appliances.
1. Greatly reduced 1. It is available most pollution. abundantly in areas with a2. Greatly reduced high number of sunshine contribution to global hours. warming. 2. It is not directly available at night or under cloud cover.3. Infinite energy 3. DC power must be resource. converted to AC power4. Reduced maintenance before it can be used. costs. 4. Initial installation cost may5. Falling production be too expensive. costs. 5. Solar panels require large6. Low running costs. land/roof areas to be7. Local application. effective.
• With the threat of global warming, and the gradual depletion of petroleum supplies, “Why we dont use more solar energy?” 1) The energy intensity of solar energy is relatively low. 2) The technology is expensive.• Solar Thermal Vs Photovoltaic. – Solar Thermal has an efficiency of 70% whereas PV 12%. – Solar Thermal requires much less space than PV. – Solar Thermal are 5 times cheaper than PV. – Difficult to add thermal walls and other passive solar collectors to an existing home which gives an advantage to PV. – Solar thermal space heating system will sit idly by during the long summer months while a solar PV system will provide usable electricity all year.• Differences between Solar panels and Solar Modules : – Technically, there is a difference, but even within the solar industry there is no clear cut answer. For all practical purposes, a solar panel is the same as a solar module.
• Solar power is a good alternative energy source. It does not hurt the environment and it is a renewable energy source.• Can be used to power houses and their electronic appliances, such as flashlights, electric motors and even refrigerators. It can also be used to heat water and cool buildings.• Two ways to capture the suns energy, by Photovoltaic devices and Solar Thermal Electric Power Plant.• Learned how solar energy can be used to make electricity and power everyday appliances.• Also learned about structures of Photovoltaic Panels, Solar Thermal and how it works.