Hybrid Grid and Energy Storage: A Step towards Adaptation, Application and

Development

BY

J.S. CHANDOK AGM(NETRA)

NETRA , NTPC LTD.

• India’s MAHARATNA & Leading Power Generating Company with 48 GW of Installed capacity with decent fuel mix. (www.ntpc.co.in)

• Installed Renewable power (Solar and Wind) of 410 MW and more than 600 MW Solar and Wind projects are in pipeline.

• Major contributor to mission of 175 GW of Renewable power by GOI : 25 GW of Solar Power.

• Solar PV with Storage project for Green Andaman : a. 8 MW SPV, WITH 3.2 MW, 1.6 MWHR b. 17 MW SPV, 6MW, 24 MWHR.

• NETRA (NTPC Energy Technology Research Alliance), R&D Wing of NTPC : focus areas of Energy and Efficiency Improvement, Renewable Energy and Climate change.

About NTPC and NETRA

• With Large Renewable penetration, Maintaining stable supply of high-quality electricity : Urgent issue with large Renewable.

• Integration with thermal power : a great Responsibility for NTPC to bring flexibility in thermal plants and in the power system as well.

• Hybridization of Renewable Resources: Complement each other and also optimize size of battery storage.

• Hybridization of Renewable resources and Battery energy storage systems : Promising option to mitigate this issue and gaining popularity.

• Combination of Battery storage ( high power & High Energy) : Required to cater short cycle and long cycle fluctuations

• Requires Adaption, Suitable applications and development of low cost battery system, NETRA is positioned to take up this.

Introduction

Development

Cost Effective Innovations

• A new kind of redox flow battery development with IISc , Banglore –Soluble Lead Redox Flow Battery(SLRFB)

• Development of Control and Protection for Hybrid Renewable Integration with IIT Kanpur

Adaptation

Trial of existing Technology

• Field trial of NAS battery under the Indian Climate and under Indian grid Condition followed by Modification in battery system as per Indian Grid .

Application

Possible applications

• Solar wind Hybrid system Installation .

• In future Solar wind Hybrid with storage.

• Setup of pilot plant for 24X7 Solar PV with Energy Storage System at NTPC, KAWAS

Hybrid Grid & Storage Activities: NTPC NETRA

NETRA – NTPC Energy Technology Research Alliance, R&D wing of NTPC Limited

NAS BATTERY DEMO PROJECT AT NETRA—FIELD TRAIL OF NAS

BATTERY

Technology Adaptation

1.2 MWHR test system

ITEMS SPECIFICATION

Battery Size 200 KW

ACTIVE POWER 180 KW

CONNECTION VOLTAGE 3 PHASE/3 WIRE/400V

Cell Temp 300 Deg C

VOLTAGE RANGE DC138~DC228 V

CURRENT RANGE ~1050 A TO +1500 A

DC RIPPLE CURRENT <10% P-P

STORAGE ENERGY 1080 kWh-ac

AC/DC CON. EFFICIENCY

95%

AUX POWER 3 PHASE/3 WIRE/400V 35 KW/UNIT

Fast response Full power charge and discharge in 1 ms

1. Under Research agreement M/s NGK Insulator Pvt Ltd Japan, NETRA is conducting field trials and testing of 1.08 MWhr NaS battery system

2. Intent : Evaluate the efficacy of system for various charging discharging pattern, including solar variation etc, In Indian environment and grid condition

3. The system is installed in Oct 2016 and shall tested and evaluated for six months upto April 17.

Basic working Principle

Operation Profiles for NAS TEST

[1-1 Rectangular] To learn the most basic performance

-200

-150

-100

-50

0

50

100

150

200

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

Po

we

r [k

W-a

c]

Pattern (a)

Pattern (b)

Pattern (c)

Pattern (d)

-200

-150

-100

-50

0

50

100

150

200

0:00 3:00 6:00 9:00 12:00 15:00 18:00 21:00 0:00

Pow

er [

kW-a

c]

Pattern (e)

Pattern (f)

Pattern (g)

Charge: 180kW x ~10H Discharge:(a)180kWx6.1H (b)170kWx7.0H (c)160kWx7.5H (d)150kWx8H

Charge: 180kW x ~10H Discharge:(a)Peak: 180kW x3H (b)Peak: 170kW x3H (c)Peak: 160kW x3H

Charge Discharge

BES

S P

ow

er

[kW

]

Charge Discharge

[1-2 Trapezoidal] To learn the performance in typical Load Leveling

1. Basic Profiles

Time

Operation Profiles for NAS TEST

D

C

Po

we

r [

kW]

2. Typical Profiles from the Solar PV simulation

D

Smoothing ＆ Energy Shift

C

Energy Shift

[2-1 Typical Sunny Day] Actual Energy Shift Capability

[2-2 Typical Cloudy] Actual Smoothing & Energy Shift capability

PV

NAS + PV

Time Time

NAS Charge

NAS Discharge

1. 24X7 PV-BATTERY STAORAGE SYSTEM AT NTPS

KAWAS

2. MULTITECHNOLOGY TEST BED FOR 5 MWp NTPC

ANDAMAN PROJECT

3. SOLAR WIND HYBRID SYSTEM AT NTPC KUDGI

Technology Application : Storage & Hybrid Grid

Solar with Battery Storage at NTPC, KAWAS

Salient Details

Location : NTPC Kawas

Area available :5 Acres

Power evacuation : Isolated colony load (290-310 KW) by two

feeder)

Configuration:

1 MW Solar and min 500 kW battery storage power, 3.6 MWHR

Flat load 24 X 7 :170 KW with 10 solar hrs and 14 battery hrs

Objective

To achieve 24 X 7 power and power on demand

Realizing Isolated grid Operation

Reliable power with both islanded and grid control operation

Smart grid features like load control, advanced protection for both operation

Solar with Battery Storage at NTPC, KAWAS

Objective: To Integrate battery storage with Floating PV & Forecasting and analyze techno-

economics for the utility of Floating PV and different battery storage system.

Configuration: 5 MW is divided into three parts of 1.67 MW each, and separate storage system is

proposed for the same.

Part Calculated Base load and

battery capacity

Proposed battery capacity*

Part 1 (1.67 MWp Solar),

8 hr operation

0.82 MW,

1 MWHR

1 MW ,

1 MWhr

(Li-ion battery / Advance Lead Acid)

Part 2 (1.67 MWp Solar), 12 hrs

operation

0.53 MW,

2.6 MWHR

0.6 MW,

2.4 MWhr (Li-ion/ NaS / Advance Lead)

Part 3 (1.67 MWp Solar)

24 hrs operation

0.25 MW,

5.0 MWHR

0.8 MW,

4.8 MWhr (NaS / Flow Battery)

*The proposed battery capacity has been selected based on available size in the market. The above sets of battery system will be procured separately as

different battery suits to different application and suitability of a particular battery for a given option can be studied

Multi Technology Test Bed

MultiTechnology Test Bed

Intent 1. Flat load operation of the 5 MWp PV Plant

2. Understanding different battery technologies for

integration with solar PV and grid.

3. Applicability of various battery technologies for

different applications.

4. Cost economic studies of different batteries in

different applications.

5. Grid stabilization study

6. Understanding O&M requirements of different

batteries in different applications.

7. Finalization of effective, cost economic application

for battery storage for renewable integration for

present and future scenarios.

8. Development of control algorithm for different

DoDs of batteries.

Objective To maximize the yield from an identified piece of land : High eff Panel

Establish the benefits of solar wind hybrid plant over the individual solar or wind plant. : Hybrid system (at DC or AC)

The effective land utilization by installing the solar PV panels in area around wind turbine avoiding shadow of the wind turbine is the objective of the project. : Land Optimization (shadow free zone 9-15 hrs)

Development of control strategy for active power control when cumulative generation of the solar and wind is above the evacuation capacity is the integral part of the project. Control with lower Evac

Pilot Plant : Solar Wind Hybrid at Kudgi

Configuration : 2 MW Wind + min 1 MW solar

Advantage : Land Optimization, Reduced cost of Evacuation, Improved Power Generation profile,

Reduction in O&M cost, Optimal sized battery storage.

Different Configurations Proposed by Different Wind

DC Integration of Solar Wind (Type 4) and storage DC Integration of Solar & storage with Type 3 Wind AC integration

AC Integration of Solar, Wind (type 4) & storage DC Integration of Solar, Type3 Wind

1. 500 W X 5 hr SOLUBLE LEAD ACID FLOW BATTERY

WITH – With IISc Bangalore

2. DEVELPOMENT OF CONTROL AND PROTECTION

FOR HYBRID RENWABLE INTEGRATION” - WITH IIT

Kanpur

Technology Development : Storage & Hybrid Grid

Soluble Lead Redox Flow Batteries

At anode,

Pb(CH3SO3)2 + 2e- Pb + 2CH3SO3- Eo = -0.13 V vs. RHE

At cathode,

Pb(CH3SO3)2 + 2H2O PbO2 + 2CH3SO3- + 2H+ + 2e- Eo = 1.49V vs. RHE

Overall cell reaction,

2Pb(CH3SO3)2 + 2H2O Pb + PbO2 + 4CH3SO3H Eo = 1.62V

Advantages :

• No membrane is required

• Single electrolyte and hence single pump

• No expensive catalyst required

• Materials are available abundantly

Electrolyte : Lead methanesulphonate salt in Methanesulphonic acid

Electrodes: Graphite foam at anode, Inter-digital fluid-flow design at cathode

“DEVELPOMENT OF CONTROL AND PROTECTION FOR HYBRID RENWABLE INTEGRATION”

Renewable Integration

Platform

Battery

Battery

Inverter

Solar

InverterSolar

PV

Solar

Inverter

440V 440V

PCC

Switch

Battery

Inverter

Solar

PV

Loads-3

Loads-2

Ethe

rnet

Control and

Monitoring PC

Control

Control

DC-

DC

Battery

DC-

DC

Control

Wind

(PM Gen)

AC-

DC

DC

Bus

Wind

(DFIG)

Control

Control

Control

Control

RTDS

1. Development of master controller for power sharing among sources and storage elements

Local controller for wind /solar/battery. Islanding/ grid connected operation, Proportional power sharing. Voltage / freq response

2. Protection scheme and load control

Fault level or grid connected or islanded operation. Adaptive protection scheme. Optimal load shedding/curtailment

3. Communication

Between various renewable sources, Battery power

4. Establishing software and management system

ADVANTAGE TO POWER SECTOR

• Controllers for AC/DC Hybrid Renewable Integration (HRI) system

• Testing and validation of controller using real time digital simulator (RTDS) to minimize uncertainty of performance in high power installations.

• In future, the developed platform could be used to conduct viability study of integrating HRI systems to the grid.

• Integrated communication to support both control and monitoring

• Coordination between the developed protection schemes and the associated controller operation

“DEVELPOMENT OF CONTROL AND PROTECTION FOR HYBRID RENWABLE INTEGRATION”

Conclusion

• With large Renewable penetration Technology Adaption, development and Pilots applications are important aspects to make path for future

• Hybrid Grid integration and sizing of optimal battery system around this is important for cost effective solution for dispatchable power

• Flexibility in the power system through Renewable resource forecasting and demand side management, smart grid aspects should be initiated.

• Understanding of Indian grid condition and modification in the control of battery PCS control is an important aspect

• Evaluation criteria for different battery system, combination of battery system with different life cycle, efficiency and application (power and Energy Intensive) is important

Hybrid Grid and Battery storage System

21

Thank You!