17 Feb 2023
Sunay Shah, Director-Projects, Navitas Solar
Indian Government is encouraging Green Growth as witnessed in Budget 2023. Solar energy will see exponential growth in upcoming years leaving fossil fuels behind. Key component in solar energy are Solar PV Modules. Design, Orientation and Positioning of the module in the plant plays a major role in maximizing energy yield. The more surface area of the module is perpendicular to the solar rays, the more energy can be harvested. Solar modules are generally fixed tilted while sun moves around in the sky which makes it a bit difficult to obtain the maximum energy generation. Correct orientation and positioning give assurance that solar modules get exposed to the sun throughout the day.
There are various aspects to be taken care of while installing a solar power plant at any location, just to mention like available open space, location coordinates of the plant, orientation of the plant, tilt of the plant etc. India has been benefited with it's extensive location which creates around 300 sunny days in a calendar year. While some of the states are indeed lucky to have ample amount of solar radiation throughout the year. Specifically to mention for Rajasthan, Gujarat and Maharashtrian Plateau. The orientation of installing solar power plant plays an important role while designing the system. Technically, it totally depends on the topographical hemisphere of the location of plant. Considering the Equator as the path of Sun's moment, there will be always an offset in direction of Sun completely opposite to the respective hemisphere i.e Northern Hemisphere countries like India, Middle East, Europe, etc. will have Sun's offset in South direction causing shadow region on Northern side. So while designing the Solar Plant in India, Solar PV Modules are orientated and tilted in South Direction. Similar to this, the rising side of Sun will cause an shadow of the obstacles in Western direction and while setting point will have it's shadow region in East direction.
The Earth's tilted rotational angle results in Summer Solstice and Winter Solstice, predominantly known as Uttarayan and Dakshinayan in India. Indian conditions fell into consideration of that Solar Modules should be flatten to surface in Winters to receive more perpendicular solar rays and moreover be inclined in Summer to get maximum generation. So the technology of variable or rotating tilt angle of Solar modules provide higher efficiency to the plant.
The residential or selectively smaller capacities which are not much affected by the seasonal changes in the radiation are installed with the Fixed Tilt of Solar Modules. The utility scale or comparatively higher generation capacities of solar plant have an option to choose from Seasonal Axis Tracker and Dual Axis Tracking System. The Seasonal Axis or Single Axis Tracker will have the variance of solar module tilt of (+-)5° to (+-)10° according to the latitude of the area. Whereas the Dual Axis Tracker has the rotary movement of modules in both axis so as to cover the maximum solar radiation throughout the day and also vary on seasonal deviations.
In general terms of solar design, optimum tilt angle of the solar modules can be determined by the latitude of the location. It's been derived through various software technologies like PVSyst that tilt angle equal to the latitude degree will generate desired optimum amount of energy throughout the year with fixed tilt orientation too. These softwares also give an overview of energy generation according to the design of plant and suggest in selection of the Solar Modules and Solar Inverter specifications. These helps in getting better understanding and optimizing the solar plant capacities and energy generation.
Manual calculation of tilt angle for the Solar Modules have two methods involved. One is general method in which the latitude is varied between +15° to -15°. So, for the latitude of 34° will give greater generation in Winters with 49° tilt angle and observe extended generation with 19° in Summers.
The other method which is moreover an improvement in general method is given as (+-) 29° to the 0.9 times of latitude angle. Considering similar 34° latitude, precisely having 59.6° and 7.1° respectively for Winters and Summer season.
No matter how precisely calculation of tilt angle is done for the solar plant, but certain losses will be there. The elusive optimum tilt angle of the panel keeps changing throughout the day and across the seasons. Therefore, the best thing any solar plant designer can do is to calculate the tilt angle that has the least average annual losses.
Some of the latitudes of leading cities of India are mentioned here and from that tilt angle can be found out. J&K, Punjab, Himachal Pradesh, Uttarakhand have latitude of 30-36 degrees. Rajasthan, UP, Delhi, Haryana, Bihar and North Eastern States have latitude of around 24-30 degrees whereas Gujarat, Madhya Pradesh, Jharkhand, West Bengal, Maharashtra, Chattisgarh, Orissa have 18-24 degrees latitude. Karnataka, Tamilnadu, Andhra Pradesh, Telangana and Kerala have 12-18 degrees of latitude. Generally, tilt angle is approximately 12 degrees in southern India and around 30 degrees in Northern India.
We at Navitas Solar having EPC department backed with our manufacturing unit are more concerned about giving the best possible solar system to our esteemed customers and hence pay more attention in Designing of Solar PV Plant considering all the necessary conditions and optimizations for getting better generation. To fulfill the vision of National Solar Mission set up by Government of India, Navitas Solar has an intense urge and eagerness to serve the solar seekers and help them with adoption of Green Energy.
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