Solar Tracker in P.T.U E.P Department

Copyright © 2019 by author(s) and International Journal of Trend in Scientific Research and Development Journal. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0) (http://creativecommons.org/licenses/ by/4.0) ABSTRACT The main importance for this paper is that sixth year students can be used laptop and projector in presentation for their mini thesis though the light is off. As four 90W solar panel is connected in parallel, total power is 360W that is reliable for our loads. In this paper, the comparison between single axis and dual axis tracker radiation for Pyay District is expressed. Moreover, Ardunio program is applied for dual axis solar tracker. Myanmar is more suitable solar power to store energy in battery during sunny days as renewable.


INTRODUCTION
Solar power in Myanmar has the potential to generate 51,973.8 TWh/year, with an average of over 5 sun hours per day. The country aims to generate 8% of electricity through renewable energy sources-through wind and solar energy-by 2021 and 12% by 2025. The weather is hottest from March-May among twelve months in Myanmar.
The following solar energy technologies can be successfully propagated: solar cookers; solar water heating systems for industrial application; solar distillation units for battery charging; solar photovoltaic systems for water pumping, battery charging, and power supply to children's hospitals for operating vital equipment. Solar air driers can be used for agricultural and industrial products.
Since Myanmar is a land of plentiful sunshine, especially in central and southern regions of the country, the first form of energy-solar energy could hopefully become the final solution to its energy supply problem. The direct conversion of solar energy into electricity using photovoltaic system has been receiving intensive installation not only in developed countries but also in developing countries.
It is mainly intended to present solar energy potential and application in Myanmar. It is also wanted to get the benefits of using solar energy for people in remote areas which are not yet connected to the national grids because of the high price of fossil fuel. MEPE (Myanma Electric Power Enterprise) experimental measurements indicate that irradiation intensity of more than 5kWh/m 2 /day was observed during the dry season.
If solar panel is installed in fixed position, solar power can absorb when the sun faces with solar panel. Even single axis moves, the efficiency of solar power can prove by comparing with dual axis as sun orbit is changing all the year.
The overall block diagram for solar tracker in P.T.U E.P Department is shown in figure 1. After light dependence resistors had sensed where the sun is, the motors can move the solar panel due to Ardunio program. The battery either can store energy from solar during sunny days or can give supply when the rainy or cloudy days. The maximum 360 W loads such as laptop and projector can draw from solar tracker through inverter.
Figure1. The overall block diagram for solar tracker in P.T.U E.P Department

A. Solar Panel of Project
Since an individual cell produces only about 0.5 V, it is a rare application for which just a single cell is of any use. Instead, the basic building block for PV applications is a module consisting of a number of pre-wired cells in series, all encased in tough, weather-resistant packages. When photovoltaics are wired in series, they all carry the same current, and at any given current their voltage add as shown in Figure2 By combing many cells, one module becomes. The electrical specification for 90 W solar panel is expressed in Table 1. Modules can be wired in series to increase voltage, and in parallel to increase current. In Figure 3, four solar module are connected in parallel so the current total value also reach nearly 20 A.   Table 2. Even in cold season, power is nearly about 76W. As April is hot season, solar radiation is the most among other months.

C. Sun Path of Pyay
The sun's position can be described by its altitude angle β and its azimuth angle φ S . Altitude angle and azimuth angle is drawn in Figure 4. Moreover, dual axis tracking system is more efficient than single axis tracking system. Trackers are described as being either two-axis trackers, which track the sun both in azimuth and altitude angles so the collectors are always pointing directly at the sun, or single-axis trackers, which track only one angle or the other. It can be proved that by using the following Equations.
Total rate at which radiation strikes a collector I C can be gotten by summing beam insolation IB and diffuse insolation on collector IDC. IC of two axis tracking is 1015W/m 2 and I C of one axis is 928 W/m 2 by substituting above equation 7,8,9 and 10. Therefore, dual axis is 9% higher than the single-axis mount.

E. Ardunio Program
To rotate dual axis, Ardunio program is applied in this paper. There are four pins for output and four sensors for East, West, South and North. There are two motors for moving. We need to command the circuit the following program.  An inverter is an electronic device or circuitry that changes direct current (DC) to alternating current (AC). The square wave inverter is one of the simplest waveforms among others such as pure sine wave inverter, modified sine wave inverter and is best suited to low-sensitivity applications such as lighting and heating. To supply AC load, inverter is required and Figure 7 is simulation result of square wave output of inverter. The straight line with blue color is DC 12 V and the square wave with red color is for output 230 V. Square wave is used when the electricity has a constant force, such as it has with DC but switches direction more or less instantly at the same kind of frequency as the normal grid supply (at 50 times per second).

Recommendations
As this solar tracker is only functional, we have many plans to continue this project. We can draw this circuit in Proteus software. We can substitute DC motor with stepper motor to be very definite by giving PIC program. The stepper motor can move step by step very detail. We can add charge controller circuit and the circuit to overcome for battery overcharging. Moreover, we can collect more data with measuring instruments with time schedule such as daily, monthly and yearly. We should consider how much cost effective and energy efficiency by comparing 360W fixed solar panel and equal power dual axis.

Conclusion
In Myanmar, renewable energy especially solar power is applied in many villages without connecting National Grid. But, they are mostly installed in fixed position. Dual axis solar tracker is very less when comparing fixed position. This project is very useful because we can give presentation even there is no electricity or the light is off. As four 90W solar panel are connected in parallel, laptop and projector can cover from this 360W solar panel. Pyay can get the efficient solar radiation so solar power is very suitable in this place.