Presented by Dr. Rahul Walawalkar

Executive Director, India Energy Storage Alliance &President & MD, Customized Energy Solutions India Pvt. Ltd

Energy Storage for Microgrids:Poised for rapid adoption

Presented at

CES is at the forefront of competitive electricity markets and

emerging technology trends

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• India• Canada• Japan• Mexico

Philadelphia, Pennsylvania

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500+ Clients Worldwide

Our consulting services enables competitive suppliers, technology providers, marketers, utilities and customers to prosper through change, by turning knowledge into value

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3Confidential (www.ces-ltd.com)

Role of Energy Storage in Indian Grid

Energy storage could play a key enabling role in every aspect of modern grid including Generation, Transmission, Distribution and at Customer Premise

(including electric vehicles)

Current Status of US & India Projects

• US drivers– Ancillary services – Solar –storage integration for peak load

& demand charge management– Microgrids for resilient grid / campus – Diesel minimization in islands

• India drivers– Diesel minimization for islands & C&I– Renewable integration– Energy access– Ancillary services for Grid reliability &

power quality

Source: US DOE Energy Storage database & India Energy Storage Alliance

Microgrid Challenges

• Coordinated control of a large number of distributed sources with probably conflicting requirements

• Limited communication imposes the adoption of distributed intelligence techniques

• Management of instantaneous active and reactive power balances, power flow and network voltage profiles

• Micro Grids are dominated by inverter interfaced distributed sources that are inertia-less while traditionally, power grids are supplied by sources having rotating masses which are essential for the inherent stability of the systems.

6Source : Agarwal & Mittal Maulana Azad National institute of tech , Bhopal

MicroGrid Challenges • Maintaining stability and power quality in the islanding mode of

operation requires the development of sophisticated control strategies which need to be included on both generation and demand sides.

• Transitions from interconnected to islanding mode of operation are likely to cause large mismatches between generation and loads, posing a severe frequency and voltage control problem.

• Instable operation during faults and various network disturbances may occur if Storage components are not there.

• High resistance to reactance ratio of the low voltage networks, resulting in strong coupling of real and reactive power. Hence the control of voltage and frequency can no longer be considered separately.

7Source : Agarwal & Mittal Maulana Azad National institute of tech , Bhopal

Microgrid – operational Challenges

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Solar Smoothing and ramp Rate Control

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Energy Storage for wind Smoothing

Wind Farm Output With Firming

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2 Hour Event 2 Second Resolution

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Demonstration of wind smoothing a 18 MW wind farm with 4 MW - 10 min energy storage.

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EES Selection Criteria

• Power Rating and Energy Capacity• Round Trip Efficiency• Service Life

– Cycle Life– Calendar Life

• System Cost– Cost per Unit Power ($/kW)– Cost per Unit Energy ($/kWh)

Advanced Lead Acid

Lead-Acid batteries consist of two electrodes: Lead and lead-dioxide immersed in sulfuric acid.

Performance measure

Cycle Life

Energy Efficiency (%)

Price Point ($/kWh)

Market leader

1200 80 200

Best in class 2000 85 300

Lead Acid

Sodium based battery - NAS

Sodium-sulfur (NaS) batteries use molten sodium and sulfur electrodes separated by a ceramic electrolyte

Sodium Based

Performance measure

Cycle Life

Energy Efficiency (%)

Price Point ($/kWh)

Market leader

4000 70 500

Best in class 6000 85 750-1000

Li-ion Battery Technology

Li-ion battery uses graphite as the anode material and LiFePO4 or LiCoO2 or Lithium titanate or lithium nickel manganese cobaltate as the cathode.

Li-Ion Batteries

Performance measure

Cycle Life

Energy Efficiency (%)

Price Point ($/kWh)

Market leader 2000 90 400

Best in class 8000+ 95 600

Flow Battery TechnologyFlow batteries use liquid electrolytes with fixed cells to store and regenerate power. Various flow battery chemistries exist such as vanadium redox, zinc-bromine, iron - chromium etc.

Performance measure

Cycle Life

Energy Efficiency (%)

Price Point ($/kWh)

Market leader 5000 60 500

Best in class 10000 70 1000

Flow Batteries

Future Advances in Energy Storage

PERFORMANCE ENHANCEMENT

• Flow batteries boast of an exceptional cycle lifetime but have a much lower roundtrip energy efficiency as compared to lithium ion batteries.

• Lead acid batteries have high efficiency and low cost but their cycle lifetime is very low compared to other technologies

INNOVATIVE materials and cell design improvements which can enhance the specific properties of respective energy storage technologies will play a crucial role in making the technologies attractive for rapid commercialization.

Key Trends in Energy Storage

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Energy Storage Landscape 2016

* In addition Thermal storage, ultra capacitors and fuel cells are also part of energy storage ecosystem

A platform for scaling technically and financially sustainable microgrids.

Combined buying power when dealing

with OEMs

Affordable electricity for end consumer

Linking electricity to economic development

of region

Better Channelizing of Funds

Data analytics for better energy management and

system modelling Reporting services for funding agencies and microgrid developers

Scaling up of Operations

Product innovation for Bottom of Pyramid

Why Microgrid Initiative for Campus & Rural Opportunities?

Database of existing & potential microgrids and

efficient equipment

Policy Makers

Funding Agency

Communication& Automation

Technology Provider

Developers

Local body

Habitants

Key Stakeholders in Off-grid and Microgrid Rural Electrification

Habitants of un-electrified remote hamlets and villages are the most important stakeholders and their aspirations and well-being are the key to viability of micro-grids.

Business and Value Proposition

System designed to monitor over 100,000 microgrids

Optimizing Microgrid design and Improving life & efficiency

Suboptimal design & operations of Inverter & Batteries can be optimized to improve economics

Power conversion at lower efficiency

Inverters were found working at lower efficiency by around 10.0% in the sites visited by CES. Either the inverters are less efficient than that considered above or probably, the battery charging efficiency is 9% or 10% lower than theoretical value. This is probably due to hard sulphate formation in battery plates, which are always operating at low state of charge and the absence of any freshening/equalizing charge regime.

Oversized plants

System build with 6 kW of solar PV are delivering less than 1 kW of output through out the day. This leads to poor return on investment, lower conversion efficiency of the inverters and idle battery capacity which can lead to incapability of the storage to deliver deep discharge during the actual requirement.

Battery State-of-charge

• SoC read by inverter at Site A was 77% and as confirmed by Exide as per specific gravity readings was 38%

• SoC read by inverter at Site B was 85% and as confirmed by Exide as per specific gravity readings was 44%

Hence, during a sunny day the power generated by plant was almost zero as the inverter had put batteries on float mode reading SoC as 85%. But unfortunately batteries were only partially charged.

Microgrid Initiative for Campus & Rural Opportunities (MICRO)

– Phase 1

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Skills Development and Integrating Microfinance for Economic Growth

Partnering with microfinance institutions and other funding agencies for supporting economic development through Sustainable anchor loads linked to village economy.

We are organizing workshops through industry academic collaborations for skill development and sharing best practices.• 1st workshop held in December 2015.• 4 regional workshops planned for

2016.

MICRO Team & Partners

Harsh Thacker,Project & Stakeholder Manager

Dr. Satish B Agnihotri,Chief Advisor

Javed Shaikh, Technical Manager and Portal Developer

Jyoti Deka, Site Inspection and Load Designing

Dr. Rahul Walawalkar,Thinker-in-chief, Chairman

Rajarshi Sen, Battery and System Design Expert

Vinay Walimbe, Progress Monitoring

Vipul Pagrut, Hardware Engineer

A diverse team developed to achieve these initiatives.

Join IESA to learn more!

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Customized Energy Solutions India Pvt. Ltd.A 501, GO Square

Aundh - Hinjewadi Link Rd, WakadPune, Maharashtra 411057 India

Phone: 91-20-32407682info@ces-ltd.com

Customized Energy Solutions Ltd.1528 Walnut Street, 22nd Floor

Philadelphia, PA 19102 USA

Phone: +1-215-875-9440Fax: +1-215-875-9490

info@ces-ltd.com

Dr. Rahul WalawalkarExecutive Director, IESA &

President and MD, CES Indiarahul@ces-ltd.com

US Cell: +1-516-639-5391 India Cell: +950-303-1765