Summer Internship Report

Acknowledgement

I express my heartfelt regards to, Mr.S.K.Chaudhary, Principal Director, CAMPS-NPTI, and Mrs Manju Mam, Director, CAMPS-NPTI whose guidance was of invaluable help for me. I am also thankful to my internal project guide Ms Vardah Saghir, Senior Fellow, NPTI for her support towards completion of my project.

I also extend my thanks to all the faculties in CAMPS (NPTI), for their support and guidance in my project.

Saarthak Khurana

Executive Summary

The current Indian Power Sector is broadly governed by the Indian Electricity Act of 2003. The basic premise of this act is to design competition in every sphere of the power sector. Trading is a very important part of a competition driven deregulated power market. For efficient trading in a deregulated power market, it is important that the energy spot market remains a valid model of the underlying physical power system during each market interval. This includes quality of supply and system security issues. This provides a valuable perspective on the role of ancillary services in the deregulated power markets. Ancillary services can be defined as those services that are necessary to ensure the system integrity and stability that provide for services not included in the energy spot market and that would not be provided on the basis of energy prices alone. The Indian power system should be operated in a safe, secure and reliable manner. In order to fulfill this obligation the state power pools should control technical characteristics of the system, such as frequency and voltage through ancillary services agreements.

The RISO/SISO should determine the ancillary services requirements on a regional grid basis and load zone basis using demand forecasts for the time frame for which the ancillary services are to be procured. As per the CERC staff paper, Frequency Support Ancillary Services (FSAS) envisage harnessing of the generation resources on pan India basis to achieve economy and efficiency. Similarly, Voltage Control Ancillary Service (VCAS) is proposed on the reactive compensation required node-wise. Black Start Ancillary Service (BSAS) is also proposed, which needs to be implemented in a coordinated manner. It is proposed that the system operator, namely National Load Despatch Centre (NLDC) should be the nodal agency for implementation of the ancillary services as NLDC monitors the real-time grid conditions on the round the clock basis.

These services can be provided by using grid connected electric vehicles. Besides this in order to meet future transportation needs, control climate change, address health issues related to emissions, and phase out dependence on oil, today's propulsion technologies have to be replaced by more efficient and environmentally friendly alternatives. Electric vehicles are such a technology that can aid the transition. A couple of countries like Germany, Denmark, and Sweden have already decided to switch electricity production from fossil fuel to renewable sources, thus further improving sustainability of electric cars when compared with internal combustion engine vehicles.

The electric propulsion systems are being developed for a wide range of medium- and heavy-duty vehicle sizes and applications, including transit buses offer several advantages such as:

• 
  Increased efficiency, potentially lowering fuel cost
  
• 
  Better acceleration, allowing quick merging into heavy traffic
  
• 
  Decreased emissions
  
• 
  Quieter operation
  
• 
  Grid Support Operations
  

Figure 1 - Schematic of charging operation of NiMH Batteries

Figure 2 - Schematic of charging operation of Li-Ion Batteries

Figure 3 - Comparative analysis of battery types

Figure 4 - SAE charging configuration and rating terminology

Figure 5 - Series hybrid design structure

Figure 6 - Parallel hybrid design structure

Figure 7 - NEMM 2020 structure

FCAS - Frequency Control Ancillary Service

NCAS - Network Control Ancillary Service

VCAS - Voltage Control Ancillary Service

SRAS - System Restart Ancillary Service

CERC - Central Electricity Regulatory Commission

NLDC - National Load Dispatch Centre

RISO - Regional Independent System Operator

SISO - State Independent System Operator

RLDC - Regional Load Dispatch Centre

SLDC - State Load Dispatch Centre

Li-Ion - Lithium Ion

NiMH - Nickel Metal Hydride

SAE - Society of Automotive Engineers

EV - Electric Vehicle

HEV - Hybrid Electric Vehicle

BEV - Battery Electric Vehicle

PHEV - Plug-in Hybrid Electric Vehicle

V2G - Vehicle to Grid

Table of Contents

Heading Page No.

Chapter 1

Introduction 1

Objective 2

Research Methodology 2

Introduction to Ancillary Services 3

Types of Ancillary Services 5

Standards and Provisions of Ancillary Services 7

Ancillary Services in Indian Power Sector 8

Frequency Control Ancillary Services 10

Voltage Control Ancillary Services & Black Start Ancillary Services 15

Nodal Agency 18

Market Surveillance 18

Issues 19

Introduction to Electric Vehicles 23

Evolution & Current Indian Scenario of EV 24

Battery Technology 26

Charging Technology 37

Drive-train Technology 41

Advantages of EV Technology 43

Govt Policies & Market Prospects of EVs 45

Introduction to V2G technology 51

V2G and Power Markets 54

Power Capacity of V2G 57

Revenue vs. Cost of V2G 59

Chapter 5

Findings and Conclusion 63

Ancillary Services have always been an integral part of the electricity industry. They were and are always needed when electricity is to be transferred reliably and delivered with satisfactory quality. In India also, ancillary services have grown along with the grid. They have traditionally been a part of grid operation and are mostly mandatory. Reforms in Indian electricity sector along with evolution of electricity markets have led to a paradigm shift and electricity is now seen as a tradable commodity, rather than just an infrastructural requirement. In a ‘market oriented electricity industry’, commercial mechanisms need to be in place for procurement of various services and to have prompt response from the entities. As a result ancillary services also should be separated from basic system services and remunerated appropriately. This gains additional strength from the fact that a structured ancillary service market would complement reliability of the power system.

The Central Electricity Regulatory Commission after detailed consultation with various system operators and load dispatch centres decided that ancillary services market was needed to aid the current Indian Power Scenario. CERC issued a staff paper on the Introduction of Ancillary Services Market in Indian Power Scenario that invited suggestions from all stakeholders. The primary providers of most ancillary services are generating stations. But the Indian Scenario is unique compared to the world as it runs a fairly high power deficit of almost 8-9%. Thus a new and more innovative approach is needed to address the issue of ancillary services market.

One such innovative idea is to use grid connected electric vehicles to provide ancillary services. This has been made possible by the ongoing implementation of smart grids in the country. It envisages that fleets of electric vehicles connected to the smart grid can be used not only to provide ancillary services but will also mitigate issues pertaining to high pollution in cities and would help reduce the dependence on oil imports for fuel thus rendering a great service to the nation. In the recent past, researches have been conducted in the developed countries to explore the possibilities of vehicle to grid (V2G) operations for load management and grid support. This report aims to study the suggested Ancillary Services Market in India, the technological and market prospects of electric vehicles and combining the knowledge to create an understanding of V2G operations whereby Electric Vehicles are used to provide Ancillary Services

The objective of this report is to study the proposed Ancillary Services Market in the Indian Power Scenario. It is aimed at also developing an understanding of the technical and commercial aspects of electric vehicles and thereby exploring the technical possibility of using electric vehicles to provide the proposed ancillary services.

The prospect of using of Electric Vehicles is named possible by the ongoing implementation of smart grids. Smart Grids can enable the use of smart grid connected loads and sources which can absorb or inject power as per requirements relatively quickly and permit the distributed storage strategy of vehicle to grid operations by Electric Vehicles.

1.3 Research Methodology

The research methodology employed is primarily of secondary research. As the field of bi-directional power transfer in electric vehicles is an ongoing subject of research in leading universities of developed nations, the report utilizes information published in various scientific journals, government regulations and legislations and research papers. Various documents from leading government agencies were consulted for the formulation of this report.

The electricity sector has been change which has been reshaping the industry. A significant feature of this change is to allow for increased competition which was the cornerstone of the Electricity Act of 2003. It promotes competition among in almost all sections of the industry and tries to create market conditions in the industry. These market conditions significantly help reduce cost of energy production and distribution, minimize inefficiencies, optimize manpower use and increase customer choice.

In this unbundled environment, important issues are also related to the type and level of services that should be included in system operation. In order to maintain the safe and reliable operation of the system, the system operator needs to its disposal various services. Therefore, it is important to quantify which system services should be provided by generators and which should be delivered by the transmission entity. Electrical power systems are designed and constructed to produce and deliver electricity at nominal voltage levels, waveform purity, phase balance and frequency. These are important attributes to the quality of supply of electricity delivered to the market participants at their respective connection points and to the integrity of the power system as a whole. Deviations from defined standards may result in economic losses to market participants, and or may jeopardize the security of the whole power system.

Trading is a very important part of a competition driven deregulated power market. For efficient trading in a deregulated power market, it is important that the energy spot market remains a valid model of the underlying physical power system during each market interval. This includes quality of supply and system security issues. This provides a valuable perspective on the role of ancillary services in the deregulated power markets. Ancillary services can be defined as those services that provide for services not included in the energy spot market and that would not be provided on the basis of energy prices alone.

Ancillary services can be defined as a set of activities undertaken by generators, consumers and network service providers and coordinated by the system operator that have the following objectives:

• 
  Implement the outcomes of commercial transactions, to the extent that these lie within acceptable operating boundaries. That is, ensure that electrical energy production and consumption by participants match the quantities specified by the outcomes of spot markets.
  
• 
  Maintain availability and quality of supply at levels sufficient to validate the assumption of commodity like behavior in the main commercial markets. This can be achieved by keeping the physical behavior of the electricity industry within acceptable operating boundaries defined by planning studies in conjunction with operator experience.
  

Ancillary services can be divided into the following three categories that are described in more detail below:

• 
  Related to spot market implementation, short-term energy-balance and power system frequency. These will be labeled Frequency Control Ancillary Services (FCAS).
  
• 
  Related to aspects of quality of supply other than frequency (primarily voltage magnitude and system security). These will be labeled Network Control Ancillary Services (NCAS).
  
• 
  Related to system restoration or re-start following major blackouts. These will be labeled System Restoration Ancillary Services (SRAS).
  

The Indian power system should be operated in a safe, secure and reliable manner. In order to fulfill this obligation the state power pools should control technical characteristics of the system, such as frequency and voltage through ancillary services agreements. The RISO/SISO should determine the ancillary services requirements on a regional grid basis and load zone basis using demand forecasts for the time frame for which the ancillary services are to be procured. All users of the system should be provided the following ancillary services.

• 
  Automatic Generation Control: The ability of a generating unit to respond to signals from the SISO/power pool in order to correct the system frequency within specified period and prevent overloading of network elements. The power pool should determine the total amount of AGC capacity required through studies that identify the amount of regulation required to meet control performance criteria and also by considering the likely variation in load over the period. This is the regulation response required to accommodate normal variations in demand and generation.
  
• 
  Governor Control: There should be inherent ability of a generating unit’s governor to correct the system frequency within a specified time frame. Provision of this service is a requirement of all generators connected to the system. All generating units are supposed to inform the power pool about the status of the unit's governor control.
  
• 
  Contingency Reserve: The generating units should be able to increase the energy output from unloaded condition in response to transmission facility contingencies on the transmission system within specified time. The power pool should determine the total amount of contingency reserve capacity required to meet control performance criteria. This requirement is a function of the larger generation units and load blocks on the system as well as the combined demand. In most instances, the larger generation and load blocks on the system will be constant, and so the contingency reserve requirement becomes a simple function of demand.
  
• 
  Reactive Power: The ability of a generator to control system voltage by the generation or absorption of reactive power should be known. Provision of this service is a requirement for all generators connected to the system. The power pool should conduct technical studies based on the quantities, characteristics and locations of forecasted demand to determine the quantities and locations of reactive support required to maintain voltage levels and reactive power margins within limit.
  
• 
  System Restart: The good response of a generator to self-start and supply the transmission system after a complete system failure is desirable. The power pool should prepare an emergency restoration plan. The power pool should determine the quantities and locations of self-start generating units that are required in order to provide system restart service. This determination should be based on contingency studies performed in the preparation of the emergency restoration plan. Such studies should, at a minimum, take into account the range of reasonable initiating disturbances, the magnitude, extent and likelihood of the outage. It should monitor the status of generation after the initialing disturbance and the system demand level at the time of the disturbance
  

The System Operators should establish the standards for ancillary services. The ancillary services standards should, at a minimum, comply with the system appropriately. The RISO/SISO may change its ancillary services standards as needed to account for variations in system conditions, real time dispatch constraints, contingencies, voltage stability transient stability and dynamic stability requirements, and other conditions. The periodic review of the operation of the transmission system should be done to determine whether the ancillary services standards should be revised.

Payments to service providers for ancillary services can be categorized as following.

• 
  Availability Payments: Due for every trading period in which the contracted generating unit is available to provide the service.
  
• 
  Usage Payments: Due, on a per event basis, for each time the particular service is used.
  
• 
  Payment for Reactive Power: Every generating unit should be able to provide a minimum amount of reactive power to the power pool which allows for dispatch instructions directing the generating unit to operate at any point within a band of specified power factor. In the event when the power pool requires reactive power from a generating unit outside this band, such that it limits the real power output of that unit, the power pool should compensate the generating unit for its lost opportunity cost.
  

Ancillary Services are support services which are required for improving and enhancing the reliability and security of the electrical power system. Ancillary Services are an indispensible part of the electricity industry. World over these services have evolved based on the prevailing structure of electric supply system and operational practices in the country. In India also, ancillary services have grown along with the grid. They have traditionally been a part of grid operation and mostly mandatory.

In vertically integrated utilities the responsibility of generation, transmission and distribution was with one organization. Ancillary services were therefore an integral part of electrical supply and not dealt with separately. However, since the liberalization of the electricity supply industry, the resources required for reliable operation have been treated as an ancillary service that the system operator has to obtain from other industry participants. In a deregulated power system the system operator often has no direct control over individual power stations and has to purchase these services from other service providers. The design of Ancillary Services market should be such that it complements system reliability.

Ancillary Services are defined, under Regulation (2) (1) (b) of the CERC (Indian Electricity Grid Code), Regulations, 2010 (IEGC) as follows:

“in relation to power system (or grid) operation, the services necessary to support the power system (or grid) operation in maintaining power quality, reliability and security of the grid, e.g. active power support for load following, reactive power support, black start, etc;”

One of the objectives of the IEGC, as given in Regulation 1.2 is the “Facilitation for functioning of power markets and ancillary services by defining a common basis of operation of the ISTS, applicable to all the Users of the ISTS”.

Regulation 8 of the Central Electricity Regulatory Commission (Power Market Regulations) Regulations, 2010, provides for the introduction of new products in Indian Electricity Market in the future, including Ancillary Services Contract. The Regulation 8 is reproduced below:

Regulation is reproduced below:

However, given the power deficient situation in the country, it would be desirable that to start with the ancillary services be simple to implement.

All the sellers and regional entities which are part of the scheduling and deviation settlement mechanism for real and reactive power with voice and data telemetry facilities in accordance with the regulations framed by the Central Commission and Central Electricity Authority to be eligible to participate in the ancillary market. No Objection Certificate (NOC)/ Standing Clearance issued by the concerned SLDC/RLDC for participation in the day ahead market in the power exchanges to be considered valid for participation in the ancillary services market subject to the condition that the capacity cleared for day ahead transaction in power exchanges for any participant plus the capacity cleared for FSAS shall not exceed the total capacity for which SLDC clearance has been obtained. Further the un-requisitioned surplus from the inter-State

Generating Stations (ISGSs) whose tariff is determined by the Commission should mandatorily bid in the FSAS.
Market Platform

The implementation of FSAS would be facilitated through bidding in the Power Exchanges. A separate product could be constituted for this purpose, comprising of sellers interested in participating in the Ancillary Service market. Competitive bidding process would be followed for procurement of FSAS. The Commission may by an order provide an overall ceiling for charges for services rendered through power exchanges including service charges for any subordinate service providers. The market participants would be free to bid in any of the Power Exchanges for providing ancillary services. The power exchanges and members of the user group to enter into ancillary services contract.

The window for receiving bids in Frequency Support Ancillary Service market to be opened after closure and clearance of the day-ahead market (DAM) in the power exchanges. The bids to be invited on a day ahead basis for which the window would be open for submitting bids considered for dispatch next day.

The principle of ensuring merit order in dispatch of FSAS bids to be discounted in case of real time congestion in the network. If dispatch of a lower cost stacked bid is likely to further stress an already congested corridor, then that bid would be skipped and the next bid in the stack would be considered for dispatch provided it also does not aggravate the condition of congestion in the network.

The Electricity Act 2003 entrusts the responsibility of transmission system planning on the CEA and the CTU. While the CEA forms perspective plans, the CTU fine tunes them over a shorter period in coordination with the CEA amongst others. While planning for the grid, the CEA and CTU, use system studies for ensuring a proper voltage profile at various points in the grid. However, the planning is done in anticipation of generators and loads coming up at various points in the grid. Due to variations between the anticipated and the actual for generation and load, the reactive power requirements change. The reactive power requirements also change as more and more elements get added to the grid.

The generators to be paid for one day capacity charges to such generators on the day of providing the BSS, as determined by the Commission. The energy charges to be paid at twice the energy charges determined by the Commission for the volume of energy supplied during the restoration process.

“Provided further that no Regional Load Despatch Centre shall engage in the business of generation of electricity or trading in electricity in electricity.”

Market surveillance would be a pre-requisite for successful implementation of the ancillary services market. Hence, a Market Surveillance Committee may be constituted comprising of the representatives from NLDC, RLDCs, RPCs, Power Exchanges and traders.

Based on the experience of implementation of various regulatory interventions the staff of the Commission have tried to identify the likely challenges in implementation of the Ancillary Services as outlined above. Some of the implementation challenges identified and pros and cons on the issues are discussed below.

• 
  Need for Ancillary Service: Concerns have been raised by NLDC at regular intervals before the Central Commission regarding grid in-discipline by the States, followed by incidences of grid collapses twice in two days. Strong corrective measures are being taken up so that such an event does not recur in future. Among other things, it is understood that there are proposals to enhance powers of the regulators in terms of enforcing grid discipline. It has been reported that system has achieved stable grid frequency since the twin grid failures owing to efforts made by various agencies. In view of this, one of the questions that arises is as to whether there is a need to introduce Ancillary Services at this stage for better grid security and stability.
  

The argument on the other side is that the Ancillary Services primarily aim at improving the reliability of System Operation. Further, ancillary services may also be seen as one of the mechanisms which could be developed to replace UI mechanism in a long run.

• 
  Payment Risk: There have been instances of default in payment of UI charges by the overdrawing entities in the past and cases are still pending in the High Courts. As many buyers of FSAS would be the same entities who are defaulting under UI mechanism, it would be necessary to ensure that these players pay for overdrawl. Since the transactions/payment would be routed through power exchanges, the power exchanges would inherit the risk of default in payment by buyers. It would require a mechanism to ensure that the buyers pay for overdrawl and secure power exchanges from such huge financial obligation/risk.
  

CERC Power Market Regulations provide for the establishment of a Clearing House. A possible solution could be considered by routing all trades by market participants through the clearing house irrespective of the participation in the Power Exchanges or Bilateral Market. Thus, some form of payment security mechanisms may be evolved for handling the payment risk through the Clearing house.

• 
  Linkage to the UI Ceiling Rate: It has been proposed to keep upper limit of UI rate, without additional UI rate, as specified by the Commission to be the ceiling price for scheduled bids. This may be seen as in conflict with the philosophy of doing away with UI mechanism in future. It may be contended that the link with UI mechanism may encourage the players to benefit by resorting to similar gaming tactics under FSAS if the prices are close to UI rate.
  

While one would be open to other proposals, it has been proposed to link the ceiling rate with UI rate to start with. Going forward, the ceiling prices may be de-linked or changed according to changing UI mechanism or indexed against a new reference in future.

• 
  Possible Breach of PPAs: One would like to contend whether we should identify flexible generation plants before implementation of Ancillary Service. It has been considered that hydro stations, especially pumped storage hydro stations, open cycle gas stations and partly load coal stations would have the capability to provide Ancillary Services in 30 minutes. It is possible that the generators may get lured by the high cost of dispatch under FSAS. This may result into in a situation where some generators try to breach the contracts/PPAs in order to supply power under FSAS. As only existing generators would ramp up and supply power as FSAS, it would be necessary to ensure that such plants do not give preference to FSAS at the cost of their PPAs. Similarly, there would be upcoming generators who would not have identified beneficiaries. Such generators may try to indulge in gaming to get better price for their power.
  

One probable solution against breach of PPAs could be to mandatorily obtain a declaration from the providers of the Ancillary Services (generators) regarding the un-requisitioned surplus capacity being committed under Ancillary Services in an affidavit submitted to Power Exchange where they participate.

• 
  Load management by utilities: Under the UI mechanism, once intimated, the overdrawing entities have an option to shed load to reduce their overdrawl. However, it may be contended by some stakeholders that in case of FSAS, high cost power shall be imposed on them which could have been avoided through load shedding. It has already been proposed that charges for the ancillary services would be payable only by the overdrawing entities. Utilities may choose not to overdraw and in such an event there might not be any occasion to incur the cost on this account. Thus, there is no imposition of additional burden as apprehended. Further, at a future date, the Commission may consider introducing “Demand Response” as a separate product.
  

• 
  Market Design: In the initial stage of Ancillary Service, market design based on Sequential Auction is proposed in which Energy Market would be cleared first and bid for balance unsold quantity of power can be made in Ancillary Service market. Experience from International market suggests that sometime this market design leads to problems of economic withholding and price reversal. As such, different market designs like Simultaneous or Simultaneous Co-optimization Auction of Energy and Ancillary Service are prevalent in the advanced markets. With introduction of different products like 10 minute and 30 minute Ancillary service, these new market designs can be tried in India.
  

• 
  Commitment Charge: Under the proposed FSAS mechanism, the generators may assume risk in terms of cost incurred in bidding everyday for supplying power under FSAS. A generator does not get surety of dispatch even if it gets clearance for the next day as its despatch is first dependent on lowering of frequency and secondly on its position in merit order.
  

There is a view that on account of the uncertainty in the despatch of generation through the Ancillary Service Market, there may a requirement to pay a commitment charge to provide sufficient incentive to attract generators to this market. However, the generator has the freedom to sell in the short term bilateral market subsequent to submission of his bid for the ancillary services. In such a case, the generator may intimate the Power Exchange and his bid would be treated as withdrawn. Thus the ancillary services provide an additional avenue for sale of power to the generators. Another option could be that the service provider be allowed to bid in two parts. While Capacity charge (which may include Start up cost) may be paid as commitment charge, energy charge can be paid for actual Ancillary Service Energy provided during system operation.

• 
  Forecasting: For optimum decision making for procurement of Ancillary Services, it is necessary that the system operator provides load generation balance forecasting on daily basis. In the Indian power System where Decentralized System operation has been adopted, providing such forecasting is a challenging job for system operator in view of the fact that it would depend on correct inputs from State Load Despatch Centers.
  

However in view of increasing Renewable participation in Indian Grid, it is required that Load Forecasting capabilities at all level are improved to avoid uneconomic decisions in procurement of Ancillary Power.

Electric vehicles (EV) are vehicles that use one or more electric motors or traction motors for propulsion. On a worldwide scale, 26% of primary energy is consumed for transport purposes, and 23% of greenhouse gas emissions is energy-related. Street traffic represents a share of 74% in the transport sector worldwide (IPCC data from 2007). In the near future, street traffic is expected to grow enormously world over, particularly in the fast developing Asian countries.

In order to meet future transportation needs, control climate change, address health issues related to emissions, and phase out dependence on oil, today's propulsion technologies have to be replaced by more efficient and environmentally friendly alternatives.

Electric vehicles are such a technology that can aid the transition. A couple of countries like Germany, Denmark, and Sweden have already decided to switch electricity production from fossil fuel to renewable sources, thus further improving sustainability of electric cars when compared with internal combustion engine vehicles.

Electric vehicles can be primarily classified into the following classes

• 
  Battery electric vehicles
  
• 
  Hybrid electric vehicles
  
• 
  Plug-in hybrid electric vehicles
  
• 
  Fuel cell electric vehicles
  

The battery charges with grid supplied electricity when plugged in via a charging device or it can also receive charge during braking through recuperation. The battery charger is a critical device since its efficiency can vary heavily between 60% and 97%, thus wasting only 3% to up to 40% of the grid electricity as heat. The motor controller supplies the electric motor with variable power depending on the load situation. The electric motor converts the electric energy into mechanical energy and, this is used with a drive train, to create torque for turning the wheels for driving.

The history of EVs in India goes back to 1996 when the first electric three wheelers were launched by Scooters India Ltd and were known as Vikram SAFA. They ran on a 72 volt lead acid battery system. In 2000 BHEL designed an 18 seater electric bus which used an AC induction motor and 96 volt lead acid battery packs. Mahindra and Mahindra Ltd also invested in electric 3 wheelers in 1999 and also created a company MEML in 2001 for making electric vehicles but it closed down due to the lack of demand of electric vehicles.

REVA, Bangalore in 2001 launce the REVA electric car which was designed by an American company – Amerigon and used advanced battery management system. Mahindra and Mahindra Ltd that redesigned the REVA to launch it as E2O.

Recently Hero Cycles collaborated with Ultra Motors (UK) to launch a range of electric bikes under the brand Hero Electric. Other companies such as Electrotherm India, TVS Motor etc are also manufacturing electric two wheeler vehicles. These bikes are generally charged at home so don’t need special adapter. Batteries motors and other kits are imported from other countries and assembled in plants here.

Department of Heavy Industries is the nodal Dept for automotive sector and has involved in funding of research, design and development of electric vehicle systems in the country. Recently MNRE also incentivized the purchase of electric vehicles through its Alternate Fuels for Surface Transport Program (AFSTP). It had an outlay of 95 crores incentivizing OEMs who were providing atleast one year service and setting up 15 service stations across the country. Also the Centre for Science and Industrial Research is involved in research on lithium batteries for electric vehicles. State governments like those of Delhi are providing demand side subsidies in addition to VAT and road tax waiver.

But overall the desired results have not been achieved. The high cost of EVs, lack of infrastructure and consumer mindset has hampered the demand. High battery costs and lack of proper charging infrastructure remain the biggest stumbling blocks in the way of mass production and adoption.

A battery is composed of a positive electrode (holding a higher potential) and a negative electrode (holding a lower potential) with an ion-conductive but electrically insulating electrolyte in between. During charging, the positive electrode is the anode with the reduction reaction, and the negative electrode is the cathode with the oxidation reaction. During discharge, the reaction is reversed, and so the positive and negative electrodes become cathode and anode electrodes, respectively. The energy storage technologies being used in most electric vehicle systems are rechargeable batteries. The energy storage units in the form of batteries can be recharged from the engine or fuel cell or from the electric grid. In the case of plug-in hybrids, the vehicles can use both common fossil fuels and grid electricity. One of the attractive features of the plug-in hybrid vehicle is that it allows the use of grid supplied electricity generated using energy sources other than the normal coal or gas such as wind or solar power.

The electrical energy storage batteries must be sized in such a way that they store sufficient energy (kWh) and provide adequate peak power (kW) for the vehicle to have a specified performance and acceleration. It should also have the capability to meet the needs of appropriate driving cycles. For vehicle designs intended to have high all-electric range, the energy storage unit must store sufficient energy to satisfy the range requirement in real-world driving conditions. Also, the battery must meet appropriate cycle and calendar life requirements. These requirements vary significantly depending on the vehicle’s driveline being designed, but they are generally not too hard to determine once the vehicle performance parameters have been defined.

It is much more difficult to establish storage unit requirements for the weight, volume, and cost of the energy storage units. There are clear upper limits on the characteristics which would preclude the successful design and sale of the vehicles. The battery is sized to meet the specified range and performance of the vehicle. The weight and volume of the battery can be calculated from the energy consumption (Wh/km) of the vehicle and the energy density (Wh/kg, Wh/L) of the battery discharged over the appropriate test cycle (power versus time).

In most cases for the battery powered vehicle, the battery sized by range can meet the power (kW) requirement for a specified acceleration performance, gradeability, and top cruising speed of the vehicle. The batteries in this application are regularly deep discharged and recharged using grid electricity. Hence, cycle life for deep discharges is a key consideration and it is essential that the battery meets a specified minimum requirement.

In the case of the charge sustaining hybrid-electric vehicle using either an engine or fuel cell as the primary energy converter and a battery for energy storage, the energy storage unit is sized by the peak power from the unit during vehicle acceleration. In most cases for the charge sustaining hybrid vehicle designs, the energy stored in the battery is considerably greater than that needed to permit the vehicle to meet appropriate driving cycles. However, the additional energy stored permits the battery to operated over a relatively narrow state-of-charge range (often 5%–10% at most), which greatly extends the battery cycle and calendar life. In principle, determination of the weight and volume of the battery for a charge sustaining hybrid depends only on the pulse power density (W/kg, W/L) of the battery. However, for a particular battery technology, it is not as simple as it might appear to determine the appropriate power density value, because one should consider efficiency in making this determination.

Specification of the energy storage requirement is critical to the design and practicality of powertrain systems using ultracapacitors. The Wh requirement is highly dependent on the strategy used to control the discharge/charge of the ultracapacitor in the hybrid-electric powertrain. Storage specifications in the range of 75–150 Wh seem reasonable for mild hybrid vehicles. The corresponding weight of the ultracapacitor units would be 15–30 kg with peak power between 18–36 kW. The round-trip efficiency of the units at these powers would be 90%–95%. The ultracapacitors would be periodically deep discharged when required to meet the driving conditions, but would operate at shallower depths of discharge much of the time. The cycle life requirement for the ultracapacitors in the mild hybrids would be in excess of 500 000 cycles.

Sizing the energy storage unit for plug-in hybrids is more complex than for either battery powered or charge sustaining hybrids. This is the case because of the uncertainty regarding the required all-electric range of the vehicles or even what is meant in detail by the term all electric range. In simplest terms, all-electric range means that the hybrid vehicle can operate as a battery powered vehicle for a specified distance without ever operating the engine or fuel cell. In this case, the power of the electric drive system would be the same as that of the vehicle if it had been a pure EV and the energy storage requirement (kWh) would be calculated from the energy consumption (Wh/km) and the specified all-electric range. Hence, for large all-electric range, the battery would likely be sized by the energy requirement and for short all-electric range; the battery would be sized by the power requirement.

To further complicate the issue of battery optimization for plug-in hybrids, the concept of all electric range can be interpreted to be mean that most of the driving is done using the battery and assist from the engine or fuel cell would occur infrequently only when the power demand is high and/or the vehicle speed exceeds a specified value.

The result would be that most of the energy to power the vehicle would be provided by the battery and effective fuel economy could be very high (100 mpg or higher). In this way, the power demand from the electric driveline (electric motor and battery) would be less than that for the vehicle to operate as a pure EV. The energy consumption (Wh/km) would also likely be reduced. Hence, both the energy and power requirements of the battery would be less demanding resulting in a smaller, less costly battery for the same effective all-electric range.

In the case of plug-in hybrids, the battery will be recharged both from the engine or fuel cell and from the wall-plug. The attractiveness of the plug-in hybrid is that a significant fraction of the energy to power the vehicle will be grid electricity generated using energy other than petroleum. Hence, for plug-in hybrids, battery cycle life becomes an important issue. The battery will be recharged from a low state-of-charge (after deep discharges) more often than for the battery powered EV. As a result, the battery cycle life requirement for plug-in hybrids will be more demanding than for the pure EV. A minimum of 2000–3000 cycles will be required. Hence, both in terms of power and cycle life, the plug-in hybrid application is more demanding for the battery than the EV application.

Extensive research efforts and investments are being put in to the advanced battery technologies that are suitable for EVs the world over. The U.S. government has been strongly supporting its R&D activities in advanced batteries through the Department of Energy. Nearly $2 billion grants have been given to accelerate the manufacturing and development of the next generation of U.S. batteries and EVs. European Commission and government organizations in Europe and Japanese Ministry of Economy, Trade and Industry (METI) are also actively supporting the R&D activities in advanced batteries. Companies like BYD, Lishen, and Chunlan have obtained strong subsidy supports from the Chinese government for the research and manufacture of advanced batteries and electric vehicles.

1. 
   Lead Acid batteries – Originally, most electric vehicles have used lead-acid batteries. This is due to the maturity in technology, very high availability, and considerably low cost. These batteries have an environmental impact through their construction, use, disposal or recycling. But the positive side is that the battery recycling rates are quite high thus reducing the ultimate environmental cost of the batteries. Deep-cycle lead batteries have up to 70-75% efficiency, but are relatively expensive and also have a shorter life than the life of the vehicle itself, and generally need replacement every 3 years.
   

2. 
   Nickel-metal hydride battery technology has matured over the years. NiMH batteries less efficient (60–70%) in charging and discharging compared to lead-acid batteries, but they boast an energy density of 30–80 Wh/kg, which is far higher than lead-acid battery. The active material in the negative electrode is metal hydride (MH), a special type of intermetallic alloy that is capable of chemically absorbing and desorbing hydrogen. The most widely used MH in NiMH today is the AB5 alloy with a CaCu5 crystal structure, where A is a mixture of La, Ce, Pr, and Nd, and B is composed of Ni, Co, Mn, and Al. The active material in the positive electrode is Ni(OH)2, which is the same chemical used in the Ni–Fe and Ni–Cd rechargeable batteries.
   

The most commonly used active material in the negative electrode is graphite. During charging, Li ions, driven by the potential difference supplied by the charging unit, intercalate into the interlayer region of graphite. The arrangement of Li+ in graphite is coordinated by the surface–electrolyte–interface (SEI) layer, which is formed during the initial activation process. The active material in the positive electrode is a Li-containing metal oxide, which is similar to Ni(OH)2 in the NiMH battery but replaces the hydrogen with lithium. During charging, the Li+ (similar to the H+ in NiMH) hops onto the surface, moves through the electrolyte, and finally arrives at the negative electrode. The oxidation state of the host metal will increase and return electrons to the outside circuitry. During discharge, the process is reversed.

3. 
   Lithium-ion batteries, dominate the most recent group of EVs in development. The traditional lithium-ion chemistry involves a lithium cobalt oxide cathode and a graphite anode. This yields cells with an impressive 200+ Wh/kg energy density and good power density, and 80 to 90% charge/discharge efficiency. The downsides of traditional lithium-ion batteries include short cycle lives (hundreds to a few thousand charge cycles) and significant degradation with age. The cathode is also somewhat toxic. Also, traditional lithium-ion batteries can pose a fire safety risk if punctured or charged improperly. The maturity of this technology is moderate.
   

The most commonly used active material in the negative electrode is graphite. During charging, Li ions, driven by the potential difference supplied by the charging unit, intercalate into the interlayer region of graphite. The arrangement of Li+ in graphite is coordinated by the surface–electrolyte–interface (SEI) layer, which is formed during the initial activation process. The active material in the positive electrode is a Li-containing metal oxide, which is similar to Ni(OH)2 in the NiMH battery but replaces the hydrogen with lithium. During charging, the Li+ (similar to the H+ in NiMH) hops onto the surface, moves through the electrolyte, and finally arrives at the negative electrode. The oxidation state of the host metal wil increase and return electrons to the outside circuitry. During discharge, the process is reversed. Li ions now move from the intercalation sites in the negative electrode to the electrolyte and then to the original site in the LiMO2 crystal. The commonly used electrolyte is a mixture of organic carbonates such as ethylene carbonate, dimethyl carbonate, and diethyl carbonate containing hexafluorophosphate (LiPF6). The separator is a multilayer structure from PP, which provides oxidation resistance, and PE, which provides a high-speed shutdown in the case of a short.