Solar Power - An Emerging Technology by R N Kumar (GM, HOD Protection and Testing) S Naved Masood (Executive, Protection and Testing)

4 Introduction o India receive 4–7 kWh/m 2 /day solar radiation with 250–300 sunny days in a year. o Highest annual radiation o Western Rajasthan o Lowest annual radiation o North-eastern region o Delhi has a share of around 4.5 kWh/m 2 /day Introduction to Solar Power o Basic Fundamentals o Solar Power at NDPL o 1 MW Solar Power Plant at Keshav-Puram. o Interaction of Installed Plants o Upcoming Projects

4 Benefits of Solar Energy o No contribution to global warming or greenhouse effects o Fuel is freely available. No dependence on any other fuel. o Almost negligible maintenance. o Generate the energy you need and where you need it. o Reduced vulnerability to power loss when it acts as backup. o Systems are easily expandable o Solar power is silent power. No contribution to noise pollution

4 Harnessing the Solar Energy

4 Photo Voltac Cells

4 The Transformation

4 A Solar Module

4 Types of Solar Modules o Mono-crystalline silicon: Most efficient technology (efficiencies of around 18% (commercial) to 28% (research) o Multi-crystalline silicon: Cheaper than mono-crystalline silicon but also less efficient. Research cells approach 24% efficiency, and commercial modules approach around 16% efficiency. o Thin film: o Cheaper than crystalline silicon but less efficient. o Various materials (amorphous silicon, Cadmium Telluride, Copper Indium Di-Selluride (CIS) Selection of the technology depending on: site, irradiation, temperature, costs vs. efficiency etc.

4 Efficiency of Solar Cells

4 Worldwide Installed PV Supply

4 I-V Curves at various levels of Irradiance

4 Maximum Power Achievement Point

4 Solar Power at NDPL CENPEID KW o Grid Interactive with dedicated load of 1.2 kW o Inverter capacity 10kVA o Auto synchronization & Isolation from grid through PCU o Remote communication using TCP-IP implemented o Metering with GSM o Project Cost : ~ Rs. 50 lakh o Project Execution Duration : ~10 weeks

4 Solar Power at NDPL Board Room KW o Direct Grid Interactive with dedicated load of 0.5 kW - without batteries o Auto synchronization & isolation from grid through PCU o Metering & Communication through CDMA being experimented. o Project Cost /Duration : 20 lakh/ 8 Weeks

4 Solar Power at NDPL NDPL Central Stores - Keshavpuram o Capacity : 1 MW - First MW size Solar Project by NDPL - Comprising 4 x 250 kVA grid connect modules - PV solar panels over covered shed area ~1.5 Acres o SCADA controlled o Project Cost : 19 Cr o Raised Civil Structure : 6 Cr o Solar Panel & Elec. Equipment : ~13 Cr

4 1 MW Plant at Keshav-Puram o 1 MW Solar Power Plant has been commissioned successfully in NDPL Central Stores : Keshav-Puram o Protection Department has provided support to the BD team for the following activities: o Scheme development o Panel wiring o Actualization of Inter panel schemes o Mapping of External trip command to RMU’s shunt trip coil o Retrofitting of RMU (110V DC shunt trip coil to 24V DC) to match control wiring voltage

4 1 MW Plant at Keshav-Puram o A total of 5576 nos. of Mono-crystalline Solar Modules are used. o Each Module is of rating 180Wp rating that combines to give around 1MWp Power. o 17 Modules are connected in an array. o 82 Strings are connected in parallel to each inverter for an output of 250KVA.

4 1 MW Plant at Keshav-Puram

4 Control Schematics at 1 MW Plant o 415V/11KV 1250 KVA Transformer is fitted with OTI, WTI, Buchholz and MOG to cater its internal faults. o Alarms through OTI, WTI, Buchholz and MOG are routed to the PCU as well as to a Buzzer. o The tripping contacts of above are routed to a shunt trip coil in RMU for isolation of Transformer in case of any internal fault. Interaction among Installed Plants o ABB’s Micro-SCADA software will be used for Control & Monitoring of the Solar Plants o The Inverter at each station shall communicate with this SCADA software over the IEC protocol through GPRS communication o A GPRS router will be installed at each Remote Solar plant and a Lease Line router at control center. o The solar plant data will be available over IEC 104 for further transfer to existing NDPL SCADA.

4 Interconnection of Solar Plants

4 Major Upcoming Projects o Distributed Solar Roof –Top project o 100MW (Peak) : 5KW/ /10000 roof tops o 50% subsidy proposed to Govt. o Go-NCTD indicated support - awaited o NDPL – Tata Power Joint Project in Rajasthan o Exploring feasibility o 500 MW (100MW NDPL + 400MW TPC ) o acres of land to be acquired around Udaipur and Jaiselmer Upcoming Projects of Solar Power at NDPL o 25 KW at DERC office o Design / Engineering Completed o Techno-Commercial Evaluation o MNRE approval received on DPR o 25 KW at CM office o Design / Engineering Completed o Techno-Commercial Evaluation o MNRE approval received on DPR o 200 KW at NDPL colony Narela o Techno-Commercial Evaluation o MNRE approval received on DPR