Introduction Due to soaring price and negative impact to the global environment of fossil fuel, demand for clean and renewable energy has increased quickly in recent years. Solar energy stands out as it is relatively easy to install and require little maintenance. Current applications range from power supply for calculators to satellites and space stations. Also, many people decide to mount solar panels on their properties to provide energy for water heating. In some countries, not only it is cheaper but owners also get paid for extra electricity they produce which is sent to power plants. Solar panels are a large amount of solar cells connected in series. Solar cells are also known as photovoltaic (PV) cells. Which means it generate electricity from electromagnetic radiation. They are made of semiconductors and utilizes photoelectric effect, thus when photon hits the material it excites electrons and create current flow. There are various factors that can affect the power output of the PV cell. In this experiment we are going to exam the effect of changing irradiance, which is the density of radiation incident on the surface, and temperature on the voltage and current output of the PV cell. In this report we will look at the theory related to factors that influence PV cell output and then two experiments designed to test the theory followed by a discussion of the results and finally a conclusion and summery. The two experiments will be discussed separately focusing on different aspects. Theory There are three important variables that determine the characteristics of a PV cell, all of which is shown in Figure 1, a graph of power and current versus voltage. The short-circuit current (Isc) is when the cell’s positive and negati... ... middle of paper ... ...ore significant effect on the voltage than the current, both in the opposite direction. Moreover, the factory data shows the temperature coefficient for Voc is -26%/ ̊C and -0.03%/ ̊C for Isc. Our result shows -0.295%/ ̊C and -0.4%/ ̊C respectively which is relatively consistent. Summary In conclusion, both irradiance and temperature affects the output voltage and current thus the power to a considerable extent. We want the PV cells to operate at its most efficient point to provide more energy per unit time, and as both factors are uncontrollable, it is important to adjust the cell to cope with the environment. For example, solar panels are usually installed a few centimetres above the roof to allow cool air to circulate. Also, some arrays are made so that it is able to turn with the movement of the Sun throughout the day in order to receive more light.
Muller, S., Prowse, D. L., & Soper, M. E. (2012, September 25). CompTIA A+ Cert Guide: Power Supplies and System Cooling | Foundation Topics | Pearson IT Certification. Retrieved March 20, 2014, from http://www.pearsonitcertification.com/articles/article.aspx?p=1945640
This chapter explains the passive solar design techniques both in general context as well as in context of havelis. It also explains the key factors of passive solar design used in havelis of Rajasthan.
The Effect of Intensity on the Power of Solar Cells This experiment involves changing the intensity of light falling on different cells and measuring their power outputs. Higher intensity of light means that there are more photons hitting the surface of the cell per unit area per second. The more hit the cell, the more rapidly the electrons move across the p-n junction, so the larger the emf produced. If the rate of movement of electrons is inhibited, then the greater the rate of supply of photons (intensity), the more will not successfully excite an electron, so the lower the efficiency of the 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
A Photovoltaic solar cell (PVSC) is an electrical device which converts light from the visible spectrum into direct current (DC) electricity (Honsberg). The International Space Station (ISS) originally used purified silicon solar cells for electrical generation. Silicon cells were primarily used as a result of their relatively light weight and heat conduction properties (Wittry, 2005). In 2001, two 38ft x 239ft solar panels were installed on the ISS. The new cells were multi junction solar cells comprised of gallium indium phosphate on gallium arsenide on germanium. The germanium based cell resists oxidation, unlike its silicon oxide counterpart that experienced degradation in the upper atmosphere due to exposure to oxygen (Wiebusch, 2001). Furthermore, the Silicon based solar cell (deployed on the
Before I go in to detail about usage and implementation of solar cells, let me explain just how they work. Solar cells, also known as photovoltaic cells (Photo= light Voltaic=electricity) capture photons, convert them into electrons, and use these electrons to transfer energy to whatever you want to power. To do this, solar cells are made with a material called a semiconductor, which, for solar cells is almost always silicon. When light hits this material, it causes electrons to break loose and flow throughout the material. By placing metal plates on the solar cell, we can capture this flow of electrons, otherwise known as current. Using the equation Power= Volts * Current, you can calculate the voltage output of a cell, which, using silicon, is about 1.1 volts- a 25% or so efficiency.
Their performance can be modelled, predicted and analyzed using equivalent circuits, and this experiment examines one of these circuits. MEASUREMENTS ------------ Short-circuit test: Primary voltage (Vsc) = 26V Primary current (I1) =
Turchi, Craig. 2010. Solar Power and the Electric Grid. edited by National Renewable Energy Laboratory.
With the growing cost of fuel for cars and the rolling blackouts of last summer, the need for an alternative, cost-effective, environment friendly energy source is escalating. Many possible solutions have been presented, such as nuclear power, wind power, and hydrogen fuel cells; prevalent among these is solar power.
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.
Preview: Today I will discuss the potential that solar power has to become this country’s main supply of energy and the latest research that can make solar power more efficient and cost effective. I will also present the environmental benefits that come with using solar power over other and more harmful forms of energy.
Hypothesis: I expect that the intensity of the light (measured by the voltmeter detected by the PVC) coming out of the light bulb to decrease as the distance in centimeter between the photovoltaic cells and light bulb increase. So I presume that the light coming out of the light bulb will reach a maximum distance covered, then the intensity will start decreasing. The relationship is an inverse relationship.
Solar is a viable alternative energy source with solar panels becoming more affordable and more efficiently designed.
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?”
The photovoltaic effect, electricity can be created directly from sunlight. Some semi-conductor materials that are exposed to sunlight can create electron-hole pairs, which can be collected to produce electricity. This occurs when photons have energy above a certain threshold. These photons have shorter wavelengths. In silicon, the threshold for electron-hole production is in the infrared region of the electromagnetic spectrum.