ROOFTOP SOLAR POWER PLANTS FOR ACADEMIC CAMPUSES

ROOFTOP SOLAR POWER PLANTS FOR ACADEMIC CAMPUSES Presented at National Symposium on Sustainable Energy Technologies for Academic Campuses at Basaveshwar Engineering College 6 th June, 2015 Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 1 of 41 Dinesh J Kagathi Power Research & Development Consultants Private Limited [PRDC],Bangalore

Contents Benefits Policy Support & Process System Configuration Working Principle Economics Photographs of a working installation Way Ahead for Implementing a Rooftop Solar Power Plant Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 2 of 41

Benefits of Rooftop Solar Power Plant 1. Solar Plant can be set up on unused rooftop space 2. Helps produce own electricity, therefore reducing dependence on grid utility 3. Provides back-up electricity when power fails 4. Insurance against electricity price increases 5. Provides attractive returns on investments savings in electricity charges revenues from sale of excess power to grid utility Diesel savings from reduced operation of DG set Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 3 of 41

Benefits of Rooftop Solar Power Plant Contd 6. Serves as a SOLAR LABORATORY to facilitate Teaching, Demonstration and R&D in Solar Energy 7. Helps the nation overcome power shortages 8. Reduces dependence on fossil fuels, thereby reducing carbon emission & pollution and contributes to better environment. Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 4 of 41

Policy Support Net Metering & Feed-in Tariff ESCOMs in Karnataka purchase excess electricity produced at Rs. 9.56/kWh for 25 years under a Power Purchase Agreement Priority Sector Status for Loans from FIs Accelerated depreciation of 80% of the system value in Y-1 Benefit under section 80 IA of Income tax, which exempts profits from Income tax for 10 years No Subsidies Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 5 of 41

Net Metering & Feed-in Tariff Solar Power TO Grid Power FROM Grid NET METER Net Metering implies synchronizing and banking of solar electricity with the grid utility so that it can be used when required. When Generation > Consumption, excess electricity is fed to the grid When Consumption > Generation, required electricity is drawn from the grid Net metering requires the use of grid-tie inverters & Bi-directional meters to measure both the export & import of electricity separately. Some states pay Feed in Tariff for excess electricity supplied to grid. Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 6 of 41

Process for Availing Net Metering Apply to concerned ESCOM (AEE) Approval by ESCOM after feasibility from grid perspective Project Construction Submission of completion report Inspection and Approval by Electrical Inspectorate Inspection & Installation of bi-directional meter by ESCOM COMMISSIONING Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 7 of 41

Recommended Configuration of SPP for Academic Campuses Solar Power Plant should work both in On-Grid and Off-Grid mode Different technological options should be incorporated Crystalline, Thinfilm and Concentrated PV modules Fixed Tilt and Tracker based Module Mounting Structures Combination of On-Grid and Hybrid Inverters Minimum Battery Back-up to be provided to energize critical loads during non-sunlight hours. Integration of Smart Load and Generation Management System (SLGMS) to match Load with Generation for Off-Grid Operation Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 8 of 41

Proposed Configuration of SLMS Different Load Centers to be identified within the Campus Each Load Center to be monitored using a Smart Meter Console Loads under each Load Center to be categorized into critical and non-critical loads Non-critical loads to be grouped based on proximity and priority and Smart Switches to be provided to each group A Control Center monitors grid availability, solar generation and Load under each Load Center through local communication network The Control Center controls the Loads to match the generation by switching on/off the smart switches through local communication network Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 11 of 41

Working Principle of Solar Plant with On-Grid & Hybrid Inverters Solar Plant will work in On-Grid mode when power is available Solar power will synchronise with grid power If Load > Solar generation deficit will be imported from grid If Load < Solar generation surplus will be exported to grid If Grid supply is interrupted, solar plant will switch to Off- Grid Mode If sunlight is available, Hybrid inverter will drive the on-grid inverters so that power generation continues SLMS will control the loads to match the generation If sunlight is not available, hybrid inverter will energize the critical loads using battery storage Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 13 of 41

Power Availability Scenarios Sr. No. GRID POWER SOLAR POWER Critical Loads LOADS SERVED Other loads POWER FLOWS AVAILABLE AVAILABLE 1 Bi-directional 2 NOT AVAILABLE AVAILABLE C Solar Power to Load 3 AVAILABLE NOT AVAILABLE Grid Power to Load 4 NOT AVAILABLE NOT AVAILABLE Battery to Load Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 14 of 41

Scenario 1c Grid & Solar Power Available Solar Power generation greater than load Power given to Grid= 50 kw Load = 150 kw Solar Generation = 200 kw Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 17 of 41

Need for Integrating Smart Load & Generation Management System (SLGMS) 1. SLGMS is essential to match Load and Generation in off-grid mode of Operation Monitors Solar Generation and availability of grid power Monitors Load under each Load Centers Controls Solar Generation and Load to match each other on real time basis in off-gird mode 2. Loads can be controlled even when grid supply is available to minimize wastage Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 22 of 41

Working Principle of SLGMS Control Center, though a local communication network, interacts with Grid Solar Inverters Smart Meter associated with Load Centers Smart Switches Control Center will exercise control over Generation and the Loads as per a Rule Management System (RMS). When Grid supply is available, SLGMS will match Load to Solar Generation to the extent possible as per RMS If Load > Solar Generation, deficit will be imported from grid If Load < Solar Generation, surplus will be exported to grid Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 23 of 41

Working Principle of SLGMS Contd When Grid supply is interrupted, SLGMS will control the Generation & Loads as per RMS on real time basis to match the two exactly If Generation > Load, SLGMS will control Solar generation If Load > Solar Generation, SLGMS will control Load by switching off non-critical Loads in a sequence as defined by RMS If Solar Generation < Critical Load, SLGMS will utilize the battery storage to energize Critical Loads If batteries are discharged, will switch on DG set Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 24 of 41

Key Drivers for Economics of Solar PV Plant Capital Cost Cost of Debt Yield / Performance Ratio Weather conditions irradiation, ambient temperature Panels Orientation tilt, azimuth Price Use for of Trackers Electricity Accelerated Depreciation Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 25 of 41

Minute wise Data logging in a typical inverter Particular Value Time(MM/DD/YYYY hh:mm:ss) 6/3/201513:14 Today Energy(Wh) 16800 Life Energy(kWh) 131 DC1 Voltage(V) 564.1 DC1 Current(A) 7.5 DC1 Wattage(W) 4249 AC Voltage(V) 254.6 AC Frequency(Hz) 50 INV Current(A) 16.3 INV Wattage(W) 4122 INV Temperature(C) 58 Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 28 of 41

Economics of a Typical Rooftop Solar Plant Description Capacity Average Electricity Generation/month (Year 1) Capital Cost Avoided cost of Electricity / kwh (Year 1) Value 200 kw 25,000 kwh Rs. 180 Lakhs Rs. 7.00 /kwh Valueof Electricity generated / annum (Year 1) Rs. 21,00,000 Savings realized net of O&M and insurance (Year 1) Rs. 18,48,000 Financing Debt:Equity Debt Equity Cost of Debt 12% 60:40 Rs. 108 lakhs Rs. 72 lakhs Equity IRR considering Accelerated Depreciation 23.25% Equity IRR withoutconsidering Accelerated Depreciation 14.74% Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 31 of 41

Way Ahead for Implementation Feasibility Study Apply to ESCOM Receive ESCOM approval Detailed Engineering & DPR Inspection by Electrical Inspectorate Submission of Completion Report & PPA Execution Project Construction Vendor Negotiations & Contracting Installation of bidirectional meter by ESCOM Commissioning O&M Institutionalization Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 37 of 41

What Engineering Colleges should look for in solar proposition The Solar PV system design should be optimal Based on state of the art Technology, Incorporating different technological options Crystalline, Thinfilm and Concentrating PV modules Module mounting structures with Fixed Tilt and Tracking systems On-grid and Hybrid inverters In accordance with latest policy framework (net metering etc.) Should work both in On-grid & Off-grid mode Maximize economic returns from the investment. Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 38 of 41

What Engineering Colleges should look for in solar proposition Contd The solar plant should include a Smart Load & Generation Management System with Smart switching capabilities System packaged with Pedagogy and Experimental Procedures to facilitate Teaching and R&D in Solar Technologies and Effective Power management. System should include instrumentation that can be used to evolve forecasting models and simulation software Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 39 of 41

Services that Colleges should look for from a Consultant 1. System Design & Detailed Project Report Preparation 2. Solution Delivery (EPC Management) 3. O&M Institutionalization & Monitoring Copyright 2015 PRDC Pvt. Ltd., All Rights Reserved 40 of 41