Solar Thermal R&D and Education @ Indian Institute of Technology Jodhpur

Funded by Ministry of New & Renewable Energy Govt. of India

Collaboration • Asian Development Bank – ICASET • STEAG India – Static & dynamic modelling & HRD • IOCL-BHEL-IITJ – Experimental CSP test beds (National facility) • NISRAF (IITK + IITB + CMMAC) – Solar resource forecasting • ABSTL – Solar convective furnace • MBM Engineering college

Energy HRD@IITJ • PhD – Current: 13 Collaborative: 1 – UG/PG Research • M. Tech. Training – Graduated: 8 HRD – Current: 11 • B. Tech. Projects Product System Integration development and Design • UGRI

Research Outcome • PhD 1. Design and characterization of volumetric air receiver. 2. Design of convective solar furnace. 3. Development of solar selective coatings. 4. Design and implementation of DC smart grid.

• M. Tech. 1. Design and development of glass-metal joints and their characterization for solar receiver tubes. 2. Design and analysis of recirculating air system in an open volumetric air receiver. 3. High heat flux characterisation and power balance of non- transfer plasma jet (with NFTDC, Hyderabad).

4. Design and Evaluation of experimental thermal energy storage. 5. High heat flux mapping of electrothermal plasma jet using semi infinite solid conduction (with NFTDC, Hyderabad). 6. Modelling of Lithium ion Cells/Battery and developing a charge controller to verify the Model. 7. Developing a programmable Emulator for the Photovoltaic Source.

B.Tech. Projects (IITJ + MBM) – Intelligent dual axes tracking – Dust deposition – Receiver testing – VARS – Air-water compact heat exchanger

STEAG: Solar Thermal Plant Simulator

Training : 6 IITJ Faculty, 10 External faculties or researchers, 18 IITJ Students are trained, 6 industry representatives are trained in association with GIZ ICASET • Training workshops 1. Smart grid. 2. Solar resource assessment and modelling (with NREL). 3. Solar thermal technology: current status, technology gaps, and R&D opportunities (with PDPU in December 2013).

SOLAR ENERGY RESEARCH Solar Resource Prediction • Time, Day and Year as input . • Predict global and direct radiationI. • Use Adaptive Recurrent Neural Network (ARNN) and Multilayer Perceptron (MLP). • Research carried out at IIT Kanpur. Daily and Mean Monthly Global Solar Radiation at 11-12am [Wh/m2]

Mean daily global solar Mean Monthly global solar radiation using ARNN radiation using ARNN Daily and Mean Monthly Direct Normal Irradiation at 11-12am [Wh/m2]

Daily Direct Normal Mean Monthly Direct Normal Irradiation using ARNN Irradiation using ARNN Hourly irradiations of all days of January 2012

Hourly irradiations of all days of January 2012 obtained using ARNN (a)DNI, (b)GHI, (c)DIF and (d) Irradiations of a random day of the month, all desired values are shown in solid lines and actual values via dashed line. Thermal Research @ IITJ  Solar air tower simulator o Indigenization o Open volumetric air receiver o Thermal Energy Storage o Air-water heat exchanger

 Dust deposition on heliostat o Mitigation of dust deposition

 High heat flux measurement (with NFTDC)

 Solar convective furnace design (application)

Solar air tower simulator (4kWth)

Thermal Energy Storage (pebble bed)

Open air volumetri Electrically receiver heated

76 T/C are employed for detailed thermal characterization of set-up and sub-systems Designed open air volumetric receiver at IIT Jodhpur

Radiation Radiation Radiation Circular (porosity 50%) Square (porosity ~ 75%) Hexagonal (porosity ~ 55%)

Hot air outlet

Re-circulating air Cold atm air injection inlet Receiver components

Target: Air temperature at the outlet = 400C; Heat flux= 600 suns Open volumetric air receiver

Simulation: Surface temperature Receiver: Electrically heated (6 re-circulation inlet)

Experiment @ IITJ- Target: 400C Mixer Design for receiver

LDV Measurement

Simulation (contour of velocity magnitude) Thermal Energy Storage

Hot air inlet: Charging

Pebble ( from Rajasthan) Simulation: Temperature contour

Thermal energy storage

Measurement Cold air outlet: Discharge)

Dust deposition on flat mirror (heliostat)

Uniform deposition Uniform deposition U U

R R

C B

st nd Non-uniform 1 2 Wind deposition h h

a a

Wind tunnel @ IIT J

Estimated threshold

velocity for initiating removal of dust High heat flux measurement

Experiment @ NFTDC Measurement of temperature

Heat flux at the inlet of cylinder is estimated for the measured temperature

Measured temperature DC Micro-Grids Motivation: . Sync PV output with DC loads. . Reduced overall losses due to elimination of multiple (AC/DC/AC) conversions. . DC micro-grids under constant power loads show severe oscillations in voltage and current. Tightly re

Schematic of proposed solar PV based DC micro-grid at IIT jodhpur Simulation results

Constant input voltage to boost converter = 200 V

Capacitor Voltage (V)

• Control algorithm for boost converter developed. • Damps V-I oscillations • Validated with experiments: Input 20 V, Output 30, 40, 50 V. • Controller can also handle variable voltage input.

Oscillations in voltage and current in supply converter of DC micro-grid under constant power loads Milestones achieved Milestones achieved . Modeling, design and fabrication of Boost converters. . Development and testing of robust sliding mode for Boost converters that ensure desired voltage regulation and stability under constant power loads. . Modeling, design and fabrication of Voltage source converter (VSC) to facilitate bidirectional power exchange with utility grid at 3 phase 440V.

Work in Progress . Development and testing of controller for grid-connecting VSC. . Development of average current sharing droop controllers for boost converters that ensures proportional power sharing among parallel connected converters. . Modeling, design and fabrication of Buck-Boost converter for interfacing battery bank and its controller.

Glass-to-metal seal development

Why?

To maintain vacuum around the receiver tube in PTC  To mitigate the degradation of solar selective coating Breaking of this seal is a pertinent issue Existing concept

Multiple joint is employed to ensure thermal expansion from steel to borosilicate tube. Patented technology! New approach: Compress seal

Development phase Kovar-Kodial: 10-10 to 10-11 mbar l/s SS-Borosilicate: 8 x 10-10 mbar l/s

Applying for a patent

Solar selective receiver coatings

• Objective – Coatings for temperatures up to 500 C and higher. – High absorptivity, low emissivity. • Tools – Electrodeposition. – Sputtering.

• Black chrome with graphite encapsulated Fe-Co nano particles – Properties of black chrome degrade > 350 C. – Electrodeposit composite. – Cr deposits on SS. – Reduction in corrosion (3.5 wt.% NaCl). – Stable in nitrogen till 500 C. – Applied for patent

• Zirconium carbonitride/Alumina – Work in progress. – Deposit sputtered. – Alumina is nitrogen diffusion barrier. – Expected to be stable till 700 C or more in vacuum.

Pilot & Demonstration Plants BARC: SOLTOP-2

IITJ-IOCL-BHEL Experimental CSP Plant Publications & workshop

Publications:  1 Journal (published)  6 Journal articles (submitted)  2 Invited Lectures  4 Int. Conf. Proceedings (IEEEXplore, ICORE)  1 Patent (applied); 1 to be applied

 Workshop :  Smart Grid  Resource Assessment  Solar Thermal Technologies (planned with PDPU) Team from IITJ, IITK, NFTDC Faculty members: .Dr. Laltu Chandra, IITJ .Dr. K. Balasubraminium, NFTDC .Dr. Deepak Fulwani, IITJ .Dr. S. Harinipriya, IITJ .Dr. V. Narayanan .Dr. B. Pratihar .Dr. A. Dixit, IITJ .Dr. Ravindra Arora, IITJ .Prof. Laxmidhar Behera, IIT K . Dr. Rahul Chibbar, IITJ . Dr. Prodyut Chakraborty, IITJ . Prof. P. S. Ghoshdastidar, IIT K . Dr. P. K. Jayakumar, NFTDC . Dr. Neeraj Gupta, IITJ . Prof. Rajiv Shekhar, IITJ

Students: • - Ph.D.: Mr. Suresh Kumar, Mr. Piyush K. Sharma (with IITK), Mr. Deepesh Patidar (IITJ), Mr. Belal Usmani; • - M. Tech: Rakesh, Nupur, Priyanka, Subhi, Digpal, Ayyaz, Ramniwas; • - B. Tech: Navneet, Darshan (SVNIT), Dheeraj, Sandip (NITD), Harshit, Tanmay, 4 students of MBM, Ankit, Project/Staff: • Mr. Vinod Kumar, Mr. Ashish Tiwari, Mr. Ritesh Patel, Mr. Anurag Gupta

Contact

• Dr. Laltu Chandra E-mail: [email protected]

• Prof. Rajiv Shekhar E-mail: [email protected]; [email protected]

Thank You!!!