Design, Fabrication and Testing of Automatic In-House Solar PV Module Cleaning System for improving Electrical Efficiency. ABSTRACT Solar Energy is the most abundant form of energy available on earth. Fortunately it is also renewable source of Energy produced by the Fusion of Helium on Sun’s surface. This Energy is becoming popular because of natural advantages. Photo Voltaic (PV) Modules are the devices used to convert solar energy in to electrical energy. The light rays consisting of Photons strike the Activated Silicon Junction Panels to produce Electrons which in turn constitutes to Potential difference across the junction there by generating current flow. Lot of high level research is going on in the areas of Materials Engineering, Silicon Junction etc to tap the complete potential of solar energy, sadly the highest efficiency commercially achieved lies between 16-22%. It is very clear from the above explanation that increase in Photons increase the efficiency, but the settlement of dust particles on Solar Panels reduce the number of photons reaching the Si junction hence, drastically decreasing their Efficiency. Presently the panels are cleaned manually, which requires lot of Labour, Water and time, It is not cost effective also. Large Solar Energy Parks requires lots of resources for maintaining which proves to be very costly. Hence there is a requirement of a system which would eliminate all these problems. In the present Work, we conduct a detailed survey on how the dust settlement affects the performance of the PV module and then design an effective automatic inhouse and cost effective cleaning system to keep the top surface of the panels clean thereby maintaining its highest possible efficiency.
Key Words: Solar Photovoltaic Module, Dust Settlement,
CONTENTS ABSTRACT AIM MOTIVATION 1. INTRODUCTION
1.1 SOLAR ENERGY 1.2 SOLAR PHOTOVOLTAIC ELECTRICAL ENERGY. 1.3 EFFICIENCY OF SOLAR PV MODULE. 2. REVIEW OF LITRATURE 3. METHODOLOGY 4. REFERENCES
AIM The aim of the project is develop an Automatic Dust Cleaning System which uses in-house power from Solar Panel and keeps the top surface of panel transparent there by increasing its efficiency in a cost effective and reliable manner.
MOTIVATION The Solar PV Systems have a very low energy conversion efficiency, i.e around 16-20 and they come at a very high cost. It means that cost per unit of power generated will be more than that of normal prevalent cost. Hence it is very essential that all the incident energy must be tapped effectively to achieve maximum utilization. We see that the vast solar panels are often covered with dust, and many Research reports say that the settlement of dust drastically reduces the efficiency and hence the power output, this pushes the energy cost upwards.
Hence, it is very clear that the panels must be maintained periodically to keep the dust off them if complete utilisation has to take place. Presently this is done by manual way and it is not really effective, many panels installed in public places are not maintained at all, making the whole exercise of installing a Solar PV System waste. The manual way of approach is not cost effective and requires lot of resources and even sometimes the maintenance schedules may be missed.
We conducted a small survey of how the Power output decreases with time due to settlement of dust. The below are the results of drop in power.
Voltage & Power
Drop in Volage & Power due to Dust 25 20 15 10
Voltage V
5
Power w
0 0
1
2
3
4
5
6
Days Drop in Current due to Dust 0.6
Current
0.5 0.4 0.3 0.2
Current A
0.1 0 0
1
2
3
4
5
6
Days
Hence it is very clear from all these facts that there is a requirement of a cost effective automatic in built cleaning system which maintains the highest panel efficience without any human intervention. This challenge made us to take up this project and deliver a product which would meet all the requirements intended.
1. INTRODUCTION 1.1 SOLAR ENERGY Solar energy, radiant light and heat from the sun, is harnessed using a range of ever-evolving technologies such as solar heating, solar photovoltaic, solar thermal electricity, solar architecture and artificial photosynthesis. Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to
harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favourable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.
1.2 SOLAR PHOTOVOLTAIC ELECTRICAL ENERGY. Photovoltaics (PV) converting solar exhibit
is
a
method
radiation into direct
the photovoltaic
effect.
of generating
electrical
power by
current electricity using semiconductors that
Photovoltaic
power
generation
employs solar
panels composed of a number of solar cells containing a photovoltaic material. Materials presently used for photovoltaics include monocrystalline silicon, polycrystalline silicon, amorphous
silicon, cadmium
telluride,
and
copper
indium
gallium
selenide/sulfide. Due to the increased demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years. Solar photovoltaics is a sustainable energy source. By the end of 2011, a total of 71.1 GW had been installed, sufficient to generate 85 TWh/year. And by end of 2012, the 100 GW installed capacity milestone was achieved. Solar photovoltaics is now, after hydro and wind power, the third most important renewable energy source in terms of globally installed capacity. More than 100 countries use solar PV. Installations may be ground-mounted (and sometimes integrated with farming and grazing) or built into the roof or walls of a building (either building-integrated photovoltaics or simply rooftop).
Driven by advances in technology and increases in manufacturing scale and sophistication, the cost of photovoltaic has declined steadily since the first solar cells were manufactured, and the levelised cost of electricity (LCOE) from PV is competitive with conventional electricity sources in an expanding list of geographic regions. Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity, have supported solar PV installations in many countries. With current technology, photovoltaics recoup the energy needed to manufacture them in 3 to 4 years. Anticipated technology would reduce time needed to recoup the energy to 1 to 2 years.
1.3 EFFICIENCY OF SOLAR PV MODULE. A solar panel is a set of solar photovoltaic modules electrically connected and mounted on a supporting structure. A photovoltaic module is a packaged, connected assembly of solar cells. The solar panel can be used as a component of a larger photovoltaic system to generate and supply electricity in commercial and residential applications. Each module is rated by its DC output power under standard test conditions (STC), and typically ranges from 100 to 320 watts. The efficiency of a module determines the area of a module given the same rated output - an 8% efficient 230 watt module will have twice the area of a 16% efficient 230 watt module. A single solar module can produce only a limited amount of power; most installations contain
multiple modules. A photovoltaic system typically includes a panel or an array of solar modules, an inverter, and sometimes a battery and/or solar tracker and interconnection wiring. Currently the best achieved sunlight conversion rate (solar module efficiency) is around 21.5% in new commercial products typically lower than the efficiencies of their cells in isolation. The most efficient mass-produced solar modules have energy density values of up to 16.22 W/ft2 (175 W/m2). A research by Imperial College, London has shown that the efficiency of a solar panel can be improved by studding the lightreceiving
semiconductor
surface
with
aluminium nanocylinders
similar
to
the ridges on Lego blocks. The scattered light then travels along a longer path in the semiconductor which meant that more photons could be absorbed and converted into current. Although these nano cylinders were used previously in which aluminum was preceded by gold and silver, the light scattering occurred in the near infrared region and visible light was absorbed strongly. Aluminum was found to have absorbed ultraviolet part of the spectrum and the visible and near infrared parts of the spectrum were found to be scattered by the aluminum surface. This, the research argued, could bring down the cost significantly and improve the efficiency as aluminum is more abundant and less costly than gold and silver. The research also noted that the increase in current makes thinner film solar panels technically feasible without "compromising power conversion efficiencies, thus reducing material consumption".
2. REVIEW OF LITRATURE The tables below will give a brief information on the litrature review done on the topics of electromagnetic pulse forming, magnetic pulse welding. Title Authors
Effect Of Dust On The Performance Of Solar PV Panel Dayal Singh Rajput, K. Sudhakar In this paper, the performance of solar PV panel subjected to environmental dust was experimentally studied. The effect of
Overview
dust on the power reduction and efficient reduction of PV module was quantified. The maximum efficiency 6.38%, minimum 2.29% without dust & maximum efficiency 0.64%,
minimum 0.33% with dust. The result shows that dust considerably reduces the power production by 92.11% and efficiency as 89%. The electrical parameter of solar panel are sensitive to the dust Conclusion
density so it is very essential to provide auto cleaning mechanism to remove the dust particles from the surface of the panel in order to ensure high performance.
Title Authors
Impact of dust on solar photovoltaic (PV) performance: Research status, challenges and recommendations Monto Mani , Rohit Pillai This paper provides an appraisal on the current status of research in studying the impact of dust on PV system
Overview
performance and identifies challenges to further pertinent research. A framework to understand the various factors that govern the settling/assimilation of dust and likely mitigation measures have been discussed in this paper.
Conclusion This paper reviews the current state of research into the impact of dust deposition on the performance of solar systems,
particularly PV and also identifies challenges to further research in this area. The appraisal on the status of research has been discussed in two phases, Phase-I appraising the research from the 1960s till the 1990; Phase-II appraising the post 1990s research in this area. Based on the exhaustive literature study a recommendation table has been developed to guide in the identifying appropriate cleaning/maintenance cycle for PV systems in response to the prevalent climatic and environmental conditions.
3. METHODOLOGY The project will be carried out in three phases namely design, fabrication and testing/validation. The details are as below :-
Design, Fabrication and Testing of Automatic In-House Solar PV Module Cleaning System.
Design
Fabrication
1. Design of Cleaning Element. 2. Design of Rack & Pinion/Belt Drive Assembly 3. Design of Automatic Controller Circuit.
1. Rack and Pinion/Belt Drive Assembly 2. Fabrication of Cleaning Element 3. Rigging of Control System Unit
The Block Diagram adopted for the present system will be as shown below :-
Cleaning System
Solar PV Module
Control System
Proximity Sensor
4. REFERENCES 1. Dayal Singh Rajput, K. Sudhakar. Effect Of Dust On The Performance of Solar PV Panel, International Conference on Global Scenario in Environment and Energy, March 2013 2. M. Catelani, L. Ciani, L. Cristaldi, M. Faifer, M. Lazzaroni, M. Rossi, Characterization of Photovoltaic panels: the effect of dust, IEEE, 2012 . 3. Islam M D, Alili A A, Kubo I and Ohadi M, Measurement of solar energy (direct beam radiation) in Abu Dhabi, UAE Journal of Renewable Energ, 2010.
4. Monto Mani , Rohit Pillai, Impact of dust on solar photovoltaic (PV) performance: Research status, challenges and recommendations, Science Direct 2010.
