Realizing the immense potential and importance of solar energy, Ministry of New and Renewable Energy (MNRE), Government of India launched National Solar Mission (NSM) in 2010 to provide ﬁllip to the promotion of solar industry in the country. This initiative also aims at promoting ecologically sustainable growth to meet the global efforts to mitigate climate changes. The availability of high quality ground measured solar radiation data in the country till 2011 was unreliable and inadequate. Limited sources of data is compiled & published by India Meteorological Department (IMD) stations and satellite data. Non-availability of bankable and investor grade ground measured solar data was a major hurdle in the implementation of solar power projects in the country. To overcome these deficiencies, they launched a national program in 2010 for the establishment of a network of Solar Radiation Resource Assessment (SRRA) stations to collect solar radiation resource data covering GHI, DNI, DHI and associated meteorological parameters in a phased manner through National Institute of Wind Energy (NIWE), by establishing an exclusive SRRA unit. Under phase-I program of SRRA, 51 SRRA stations have been commissioned in 10 states and 1 UT and under phase-II sanctioned in 2013. Another 60 SRRA stations have been commissioned in 17 states and 3 UT cover the entire India. Besides the SRRA stations , 4 advanced measurement stations also have been commissioned under phase-II in the country to collect site specific attenuation of solar radiation due to various atmospheric constituents . NIWE has thus established the world's largest solar radiation monitoring network, spread in 115 locations across India. High resolution 1 minute data from these 115 stations are received through GPRS technology in the server established in NIWE and a fully automatic quality control mechanism as per international standard is in force for data cleaning to make the data reliable.
For the development of solar power plants, high quality ground measured solar radiation data is essential.
A typical SRRA station consists of two towers of 1.5 m and 6 m tall. The 1.5 m tall tower is equipped with a solar tracker, one Pyrheliometer and two pyranometers (one with shading disc) to measure direct, global and diffuses irradiance respectively. The 6 m tall tower houses meteorological sensors for measuring ambient temperature, relative humidity, atmospheric pressure, wind speed & direction, rain fall and a state of-the-art data acquisition system. The solar sensors are traceable to World Radiation Centre/World Radiometric Reference (WRC/WRR) and the meteorological sensors are traceable to the World Meteorological Organization (WMO) respectively. The SRRA station is powered by solar energy for independent operation and has power autonomy for a week. A trigger switch is also part of the SRRA station to track the cleaning status of the station on a daily basis.
One hundred and eleven (111) SRRA stations have been commissioned in the country in 29 States and 3 Union Territories (UT) during the period May 2011 to June 2014. The speciﬁcations of the sensors / instruments used in both the phases are identical, except for the inclusion of lightning arrestor and energy meter in the second phase of SRRA stations. Data collection sampling is 1 sec and basic data average is 1 minute.
To quantify the site specific attenuation of solar radiation due to various atmospheric constituents, four AMS have been established in the country one each in North, East, South and West respectively at National Institute of Solar Energy (NISE),-Gurugram, Indian Institute of Engineering Science and Technology (IIEST)- Howrah, Prathyusha Engineering College (PEC)- Tiruvallur and Gujarat Energy Research and Management Institute (GERMI)- Gandhi Nagar (Gujarat). As the scattering and absorption etc. are wavelength specific, ten independent narrow wavelength channels are used for the solar spectrum analysis. Each wavelength has an independent Collimator and Detector for simultaneous measurement of all wavelengths. AMS is also equipped to provide information on Aerosol Optical Depth (AOD) of the atmosphere, reﬂectivity of the earth's surface (Albedo), incoming long wave radiation (sky radiation) and atmospheric visibility for Research & Developmental purpose.
Development of an Indigenous solar power forecasting model for the country has been initiated with technical support of GIZ, New Delhi and an operational model is likely to come out by March 2019.
A concept feasibility study on Virtual Power Plant (VPP) in India in association with GIZ GmbH, New Delhi, Fraunhofer IWES, Germany and ICF International has been initiated. Virtual Power Plant is a network of decentralized, medium-scale power generating units such as, wind farms, biomass and solar parks as well as flexible power consumers and batteries. The sources are often a cluster of distributed generation systems, and are often orchestrated by a central authority.
|Typical SRRA Station||Advanced Measurement Station|
|Calibration Laboratory||Mobile App Logo|
|Atlas DHI||Atlas DNI||Atlas GHI|