Solar Panel Technology Design Team 7: Nathan Vargo Tianhang Sun Spencer Krug Liqing Yao Qifan Wang

What is it? Solar panel refers to a panel designed to absorb the sun's rays as a source of energy for generating electricity or heating. A photovoltaic (PV) module is a packaged, connected assembly of a collection of solar cells. Solar Photovoltaic panels constitute the solar array of a photovoltaic system that generates and supplies solar electricity in commercial and residential applications.

History 1839 Edmond Becquerel discovers photovoltaic effect 1954 development of silicon photovoltaic technology by Daryl Chapin, Calvin Fuller, and Gerald Pearson 1958 n-on-p silicon photovoltaic cells 1958 first satellite launched with pv powered systems 1970 cheaper solar cells available to public 1990 first grid-supported photovoltaic system

How Does This Technology Work? Photovoltaic effect Semiconductors Solar cells Solar arrays Energy storage

Photovoltaic Effect The photovoltaic effect is the creation of voltage or electric current in a material upon exposure to light Band gap energy Valence and conduction bands Electron hole pair Return to neutral state

Semiconductors Silicon Dopants p-n junction Potential barrier boron and phosphorous p-n junction charge neutrality depletion region Potential barrier electrons free to flow without hindrance of holes

Solar Cells Antireflection Coating Front Contact n-type silicon Electrode n-type silicon p-type silicon Back Contact 0.5V to 0.6V untreated silicon reflects more than 30% of light incident on it silicon monoxide (Si0) good antireflective coating double layer reduces reflection to 3% texturing the top surface of cell also reduces reflection

Solar Array Construction Cell to Module to Array Module Connection of cells Most cells connected in series Typically 36 cells Array Series or Parallel Tied to grid Lenses and mirrors Tracking devices cells need only be joined to. one another in progressive size levels until Jheir individual power contributions add to that fulfilling a designed need

Storing PV’s Electricity Tied to grid Insufficient solar energy, power taken from public grid Sufficient solar energy, power sent to public grid Batteries Expensive Not very efficient

Advantages Green Energy Unlimited source/Renewable Energy Source No pollution Slow/Stop global warming Unlimited source/Renewable Energy Source Gas, Coal and other limited power source are running out Unlimited power source: solar, wind, etc Saves money Only cost initial setting fee, then free energy Data from cleantechnica.com: “The average 20-year savings for Americans who went solar in 2011 were projected to be a little over $20,000. In the populous states of New York, California, and Florida, the projected savings were over $30,000. In the sunny but expensive paradise known as Hawaii, the projected savings were nearly $65,000!”

Advantages Creates jobs Solar power creates 2 to 3 times more jobs than coal or natural gas.

Disadvantages Initial cost fairly high Night and cloud limit Not able to create power when there is no sunlight Power generated reduced during times of cloud cover Uses a lot of space High buildings may not get enough energy from solar panel Energy storage is expensive Good solution for night and cloud limit but quite expensive Less efficiency than other power source 14%-21% efficiency due to today’s technology limit Can not generate power as fast as other power source

Current Technology Double sided Silicon material solar cells efficiencies up to 15% Single sided Silicon contact cells efficiencies up to 25% Concentration using curved cells and lenses intensify light and use heat generated for conversion Concentrating Solar Power(CSP) Using reflective materials like mirrors and lenses, these systems concentrate sunlight to generate thermal energy, which is in turn used to generate electricity. Similar to traditional power plants, many CSP plants are hundreds of megawatts (MW) in size and some can continue to provide power after sunset

Applications Solar Heating & Cooling (SHC) Solar Roadways These technologies generate thermal (heat) energy for water & pool heating and space heating. Some people are surprised to learn that SHC technology can also be used for cooling. Solar heating technologies are cost-effective for customers in a variety of climates. Solar Roadways Netherlands already is applying solar energy to building roads. There are very small solar cells integrated with the road structure. This solves an issue of the large amounts of space solar panel arrays require. Power Storage/Transmission Solar technologies directly produce electricity which can be used, stored, or converted for long-distance transmission. PV panels can be manufactured using a variety of materials and processes and are widely-used for solar projects around the world.

Applications Solar Communication Solar Irrigation Monitor remote locations without the need to route power from electrical grids. With solar technology, power can be obtained in almost any remote location. Solar Irrigation Solar power can also be used to produce hydraulic pressure for irrigation systems on farms.

Eyes to the Future Gallium Arsenide instead of Silicon Colloidal Quantum Dots Extract unfiltered sunlight from space Solar Windows High-speed space travel solar sail, theoretical max speed ~10% speed of light! NASA has developed several concepts for a space-based solar power station. This one is called the Sun Tower and would involve an array of inflatable circular solar concentrators. Even before any energy is produced, it is estimated to cost at least $12 billion.

Our Project: Early Warning for Solar Power Actually not directly related to solar panel itself Reason for our project: Significant power drop when clouds cover the solar panel for a long time. Early Warning of when the cloud will cover the solar array on campus is needed. MSU can buy the electricity from another company to make up the power drop (expensive), or turn on backup power which takes several minutes. Using light sensor to detect the approximate amount of solar power. Solar energy sensor is expensive (~$200) compared to light sensor (~$5) for PoC design.

Questions