1. Introduction The shading is the most important causes of vulnerability for the power output of PV module. 5% (for example) of shading on the PV module leads to a decrease in the ability of the module may reach more than 60 or 70% of the module power. This is due to, the connected cells in a string, where the cell with the lowest illumination is the main reason for the reduction of the current series in full. On the other hand, it is possible that the cells become shaded reverse biased, and power dissipation by the rest of the cells of the string, this creates a “hot spots”, which have the thermal potential to destroy the module. That is why on PV modules it should avoid all causes of shading. Shading due to the buildings, chimneys, trees, towers, or even by other parts of the same building. 2. Research 2. 1. Previous Researches Shading, which is located on a cell of a group of cells connected in series string, leads to the reverse bias in these cells, reverse bias and the microplasma breakdown have been explained and described physically by Bishop (1988). a comprehensive analysis have been made of the reverse biased solar cells, and applied to Bishop's model by Kovach (1995), in order to obtain conclusions regarding a hot spot formation and the yield reduction of PV panels. Alonso and Chenlo (1988) gave measurements for crystalline cells and amorphous cells led to a commercially made available. Kovach (1995) again found that the poor PV panel lay-out and under the same conditions of shading leads to a significant energy losses, and even small shadows can significantly affect the return of energy. The researchers also observed that all the solar cell I-U characteristics in reverse bias shows more variation from bias ... ... middle of paper ... ...ctrical behavior of shadowed PV arrays. Firstly, Rauschenbach (1968) presented a mathematical description of the PV arrays shaded. After that, Abete et al. (1989) studied the behavior of solar cells connected in series and parallel, which subjected to partial shade by applying the Bishop's model. Today, the commercial market prospers with a very large number of software tools that could assess the behavior of PV arrays. But not all of them are fit tests solar cell level under reverse biased conditions (Zehner, 2001). RESEARCH QUESTIONS: - How to estimate the reduction in energy yield of partially shadowed PV systems? - How to make changes in system design to make improvement in energy production efficiency? - What are the latest methods that can be adopted to overcome demerits associated with shading? - What are the advantages of using micro inverter ?
Analysis of the Absorption of Green Light Versus Red Light Absorption in Spinach Leaves. The goal of the experiment was to determine if green light had less ability to absorb than red light in spinach leaves. This was done by separating the photosynthetic pigments (chlorophyll a, chlorophyll b, carotene and xanthophylls) from one another using paper chromatography. The separated pigments were then analyzed for their absorption spectrum using a spectrographometer.
Whether we were born in Africa, or our ancestors originated in such a peaceful place, all of us have some connection to the developing continent. As time has passed, it has become more and more clear that the start of the earth’s population, originated in the heart of Africa. Through the harsh conditions, several species survived and began to spread to various other parts of the continent, and the rest of the world. From six species to three, moving across the country is what allowed our people to expand knowledge, technology and even just adapt to new climates. Being in a warmer environment, closer to the sun, it is necessary for the skin to absorb more sun rays, thus making and keeping the skin a darker color/shade. As time progresses and
The Solyndra Company, founded in 2005 by Christian Gronet, designed, manufactured, and sold a unique type of solar panels. They were termed “solar photovoltaic (PV) systems” and were designed for large, flat to low sloped commercial building roofs. The panels were designed to have the best performance when mounted horizontally and to be installed very close together so that they covered a much higher percentage of the roof top thus producing more electricity than the typical flat panel solar panels by comparison. This was created through the production by absorbing light from all directions including indirect and reflected light as well as direct sunlight when combined with a white roof. This was due to the design of having rolled its copper indium gallium selenite or CIGS into a cylindrical shape. Each tube had 40 of them in each 1-meter-by-2-meter panel (Solyndra, 2008).
I have calculated the amount of light hitting the cell by the ratio of area of the cell to the ratio of area over which light is spread: intensity = power from bulb x surface area of cell 4 pr2 The power from the bulb was worked out from the current through the bulb and voltage put across it by the power pack. An estimated efficiency of 2% was used. Outline: I varied the distance of the light source from the cell, then took readings from a voltmeter in parallel, and an ammeter in series, with the solar cell.
The effectiveness of PV module depends on how perpendicular the sunrays fall on the PV. If PV is facing toward the sun, it produces maximum power. Stationary solar panels cannot face toward the sun all day as sun moves. However, maximum radiation depends on two other aspects of stationary solar panels. One is the direction and the other is the tilt angle of the panels. A meter long panels can generate maximum of 1000W, if sunlight strikes directly on it. Few factors affect the sunlight strikes a PV panel. When the sunlight passes through the air, air molecules such as dust, vapor, clouds, volcanoes can absorb some of the radiation. This absorbed part of radiation is known as diffuse solar radiation. Atmospheric conditions have great effect on solar radiation. The solar radiation can decrease 10% to 100% depending on
Carbon dioxide laser, a recent development, emits extremely high energy. It vaporizes the scarred skin tissue layer leaving fresh skin behind. The benefit of this process is that very less medical complications are associated with this.
...rket share (Please refer to Figure: 6). The increasing opportunity and market growth is promising in the countries located in sunbelt region like India, China, Mexico and Australia (Please refer to Figure: 7) as all these countries are highly populated and in need of power. By 2020, demand for solar installation will reach to 84 GW globally and China alone could add up-to 10 GW of PV installations each year, as announced by the Chinese authorities (global market outlook).
have make-up to cover our faces with, Botox and collagen injections to make us look
The solar panel, is able to work through solar modules using light energy, or photons, from the sun to generate electricity through the photovoltaic effect. The photovoltaic effect is the creation of voltage or electric current in a material upon exposure to light. A research conducted by Imperial College, London has improved a way of making solar panels much more efficient by studding the light-receiving semiconductor surface with aluminum nano-cylinders which are fairly similar to the ridges o...
The main purpose of green nanotechnology has been to develop clean technologies that would minimize potential human and environmental health risk. Also, to encourage replacement of existing products with the clean technologies that is more environmentally friendly. There are many benefits of using green nanotechnologies as the new solution for energy in both their current availability and their current development. Over the new few decades, the highest growth opportunities will come from application of nanomaterials for making better use of existing resources. Nanotechnologies will help reduce weight of carbon emission in transportation utilizing nanocomposite materials that quickly diffuses across the automotive and aerospace industries. Applications of nanotechnologies will result in a global annual savings of 8000 tons of carbon dioxide, which will rise even further to over millions tons by 2020. But, let’s focus on the positive effects of Green Nanotechnology in Solar.
How Efficient is Solar Energy Technology? Engineering Challenges. n. d. a. d. a. d. d. 8 April 2014. http://www.engineeringchallenges.org/cms/8996/9082.aspx>. How do Nuclear Plants Work?”
Solar power is energy efficient, what is meant by that is that solar power cannot ever run out as long as it is installed properly. Solar power cells is a source of electrical energy that converts a powerful source of energy such as the sun into electricity, using it’s energy to create electrical currents within the solar panel. Solar panels produce electricity using technology called “Solar Photovoltaic (PV)”.
The Earth captures around 342 W/m2 of energy from the sun. This energy is in the form of solar radiation, which the atmosphere reflects about 77 W/m2 and will absorb around 68 W/m2 of solar radiation annually. Therefore, the Earth’s surface is receiving, on average, about 197 W/m2 of solar radiation annually. This amount of energy received is roughly more than 10,000 times the amount of all energy humans consume per year. This energy can be used to produce electricity or heat. This energy source is not being used to it’s potential considering how much effort would come into effect to store and transport this energy.
The total world energy demand is roughly 400 quadrillion British Thermal Units (BTU). One BTU is measured by the energy and heat generated by a match. Currently, renewable energies only make up about seven percent of the world's energy demand (McLamb, 2011). Despite those low numbers, solar power is quickly becoming mainstream. In 2012, the world acquired the capacity to produce more than 100 gigawatts (GWs) of electricity from sunlight. This surpassed growth predictions for solar photovoltaic capacity made only 10 years ago. The total installed capacity is expected to reach nearly 330 GW by the year 2020 (Frishberg, ...