New Delhi,13 May:Solar Energy Centre (SEC) has developed facilities for research, development and evaluation of solar thermal and solar photovoltaic (PV) technologies. PV modules generate electricity as long as the sun shines. It is, however, necessary to qualify these modules for their performance and life before their large scale deployment.
Sun SimulatorThe existing sun simulator at the Centre is capable of testing the performance of PV modules of dimensions upto 150 cm X 70 cm. The environmental conditioning tests of these PV modules of capacity upto 75W are carried out through different environmental chambers that simulate various temperature, humidity and radiation conditions. These modules of 75W or less capacity are being deployed in large scale in the country for lighting communication, pumping and also power generation. In India there are large number of manufacturers of PV modules and systems and many of these modules are currently been exported to meet the ever increasing demand in many parts of the world.
For large capacity applications like MW size PV power plants now the size and capacity of commercially available photovoltaic modules have been increasing mainly to reduce the overall cost. With the large area sun simulator. it would be possible to evaluate the performance of PV modules of size 200cm X 200cm, the capacity of which can be around 600 W. Initiatives have already been taken by SEC to design and procure environmental chambers to accommodate such large area modules for their qualification testing. It is expected that the complete test facility for large area modules will be in place within a year so that performance and qualification testing of large area PV modules can be undertaken at SEC as per international standards.
International Accreditation
The center is also in the process of obtaining international accreditation of the test facility. This facility would help PV module manufacturers of the country to test their product in India and find a market in other countries of the world. SEC has also taken up an initiative in collaboration with Central Electronic Ltd. , Indian Association for Cultivation of Science (IACS) and National Physical Laboratory (NPL) for development of secondary reference solar cells and modules in the country. These initiatives will facilitate PV industries in the country to be more confident and competitive international.
The other system inaugurated by the Minister is a photovoltaic concentrator module test bed. This facility is unique of its kind in India and uses the latest high efficiency multi junction concentrator solar cells technology modules. The concentrator modules along with a high precession tracker system have been provided by MBPV and the balance of system (BoS) components of the test bed, the inverter, the battery bank, necessary loads and the Data Acquisition System for performance monitoring have been conceptualized and organized by SEC.
The major components of the concentrator system are six numbers of concentrator photovoltaic modules, each containing 16 high efficiency multi-junction GaAs solar cells. The cells and the concentrator unit are fabricated by M/s SolFocus, USA and M/s MBPV respectively as a part of their joint venture project. These cells operate at 500 suns concentration and each concentrator module generates about 205W under standard concentrator conditions (ASTM WK 6450). There are 6 such modules generating a total power of 1.2 kW. The module efficiency is 17%. The unique design of the concentrator uses three optical elements, and offers a wide insolation acceptance angle ±1 º.
The BoS consists of high performance solar charge controller to charge a battery bank of 24 Volts, 500 Ah, connected to a high efficiency SMD (Solar-Mains-Diesel) hybrid inverter of 2 kVA. The loads include the lights, fans, control PC, and a 300W flood lamp. For monitoring the performance of the system, SEC has established a DS-10 Data Acquisition System (DAS) based on CSI 21-X Data Logger. The sensors for monitoring the current, voltage, sun radiation, temperature, wind speed direction, and meters for recording the total AC energy supplied by the system. The DAS is programmed to monitor the performance data very precisely every 10 sec and average over 10minutes. Initial observations indicates that the 1.2 kWp concentrator systems could generate more than 4.5 kWh of D.C. energy in a normal sunny day.