Role of Energy Storage Technologies in Providing Ancillary Services, Improving Power Quality and Reliability of the Indian Grid India need regulations for energy storage to implement grid ancillary services Technical Session 1: 17 th March 2016 Mr. Debi Prasad Dash Manager, India Energy Storage Alliance (IESA) Sr. analyst, Customized Energy Solutions Co-Author: Dr. Rahul Walawalkar, President, CES India & Executive director, IESA
Current Scenario of India Currently India operates one of the largest electric grids in world with total installed capacity of over 250+ GW. Managing variability of electricity load has been a challenge for the grid operators in India, especially as over 59% of power generation capacity is met by coal thermal plants which do not have the capability to respond quickly to fluctuations in the power demand and supply. Apart from this, rise in the wind power and other renewable energy supply, which consist of over 13% of the generation mix in India, has led to uncontrolled variability on the generation side. Such a scenario has led to questions on India s preparedness to maintain grid stability, especially after the grid failure in 2012. The primary mechanism used for Grid Discipline has been the Unscheduled Interchange (UI) mechanism
Electricity Market in India Source: IEX
Evolution of India Grid Frequency Control Jan-14 Apr-12 May 2010 Apr 2009 Before Apr 2009 48.8 48.9 49.0 49.1 49.2 49.3 49.4 49.5 49.6 49.7 49.8 49.9 50.0 50.05 50.1 50.2 50.3 50.4 50.5 50.6 50.7 Freq Band Tightened UI Vector Tinkered 48.8 48.9 49.0 49.1 49.2 49.3 49.4 49.5 49.6 49.7 49.8 49.9 50.0 50.05 50.1 50.2 50.3 50.4 50.5 50.6 50.7 Indian grid regulations have tried to address some of the technical characteristics of ancillary services through existing mechanisms such as Unscheduled Interchange (UI) mechanism and power factor incentives. Over the years, CERC has tightened the frequency band. CERC had also issued a staff paper on Ancillary Services in December 2013. These mechanisms have served their purpose by improving the grid conditions as compared to prevalent issues but need to get augmented / replaced by systematic introduction of ancillary services in the coming years. Source: CES/IESA Internal Analysis
India Grid Frequency 2011 Source: CES Grid Frequency Monitoring system
India Grid Frequency 2015 Source: CES Grid Frequency Monitoring system
Definition and Common Ancillary Services Ancillary services have been developed in many of the restructured power system regions especially in the developed and deregulated electricity markets. Ancillary services include the services that support the provision of energy to support power system reliability and security. The ancillary services markets are tied with the design of the energy market therefore need careful consideration of power system economics. To support the scheduling of energy on power systems, operators require ancillary services.
Draft Frequency Regulation Mechanism - 2015 At present, around 5000MW interstate generating capacity is not getting requisitioned. CERC intends to tap this capacity for initiating Ancillary services. Objective of proposed Reserves Regulation Ancillary Services (RRAS) is to restore the frequency level at desired level and to relieve the congestion in the transmission network. All Inter-State Generating Stations whose tariff is determined or adopted by the Commission and are operating on part load and have not received full requisition shall be eligible to participate in the Reserves Regulation Ancillary Services Market. Although these rules are a step in right direction, relying on stranded capacity for ancillary services such as frequency regulation may not be most economical. As it has been seen in US, energy storage technologies are more efficient and cost effective for procuring fast frequency regulation service to the grid and thus help optimize the grid resources better than use of conventional fossil generators.
Technical Benefits of Energy Storage As understood from the US market, energy storage technologies have better capabilities to cater to ancillary services like frequency regulation, load following, voltage support, reactive power supply, black start and others than the thermal, gas and renewable energy power plants. ESS (Energy Storage System) can provide ancillary services with much better response time. Emerging ESS (beyond traditional, pumped hydroelectric storage) may provide several technical benefits for utilities, power system operations, and users. The traditional applications for energy storage are described below: Grid Stabilization: EES can be used to help the transmission or distribution grid return to its normal operation after a disturbance. Energy storage can be used to remedy three forms of instability: rotor angle instability; voltage instability; and frequency excursions
Grid Operational Support: In addition to stabilizing the grid after disturbances, energy storage can also be used to support normal operations of the grid. Frequency Regulation Services: Energy storage can be used to inject and absorb power to maintain grid frequency in the face of fluctuations in generation and load. Contingency Reserves: At the transmission level, contingency reserve includes spinning (or synchronous) and supplemental (nonsynchronous) reserve units, that provide power for up to two hours in response to a sudden loss of generation or a transmission outage. Voltage Support: Voltage support involves the injection or absorption of reactive power (VARs) into the grid to maintain system voltage within the optimal range. Energy storage systems use power-conditioning electronics to convert the power output of the storage technology to the appropriate voltage and frequency for the grid. 10
Black Start: Black start units provide the ability to start up from a shutdown condition without support from the grid, and then energize the grid to allow other units to start up. A properly sized energy storage system can provide black start capabilities, provided it is close enough to a generator. Power Quality and Reliability: EES is often used to improve power quality and reliability. The vast majority of grid-related power quality events are voltage sags and interruptions with durations of less than 2 seconds, phenomena that lend themselves to energy storage-based solutions. Load Shifting: Load shifting is achieved by utilizing EES for storage of energy during periods of low demand and releasing the stored energy during periods of high demand. Load shifting comes in several different forms; the most common is peak shaving. Peak shaving describes the use of energy storage to reduce peak demand in an area. 11
Project Demonstration: Beacon 20 MW Frequency regulation plant, NY Beacon s Stephen Town Frequency regulation plant (20 MW- 5 MWhr) utilizes 200 high speed flywheels to provide fast frequency regulation service to NYISO since 2011. It helped in creation of FERC order 755 establishing pay for performance market design for frequency regulation in US. Beacon flywheels perform between 3,000 and 5,000 full depth-of-discharge cycles a year. Figure 1: Beacon 20 MW Frequency Regulation Plant, NY (Source: Beacon Power) Source: DoE Energy Storage Database
Technology suitability for various Ancillary Services Thermal Renewable Energy Storage Technologies Frequency Regulation Synchronous Reserves Non Synchronous Reserves Operating Researves Voltage Support / Reactive Power Load Following / Energy Imbalance Coal 25% 100% 0% 0% 25% 100% Gas - CC 100% 100% 100% 100% 50% 100% Gas - CT 100% 100% 100% 100% 50% 100% Nuclear 0% 25% 0% 0% 25% 0% Diesel Generator 50% 100% 100% 100% 0% 100% Hydro 100% 100% 100% 100% 50% 100% Wind Solar 0% 25% 0% 0% 25% 0% 0% 0% 0% 0% 50% 0% Lead Acid 0% 100% 100% 100% 50% 100% Li-Ion 100% 100% 100% 100% 50% 100% Flow Batteries 50% 100% 100% 100% 50% 100% Other batteries 50% 100% 100% 100% 50% 100% Flywheel 100% 100% 100% 100% 50% 0% Pumped Hydro 100% 100% 100% 100% 50% 100% CAES 100% 100% 100% 100% 50% 100% Demand Response 25% 100% 100% 100% 25% 25% Although most of these technologies are technically viable for utility-scale systems, some are believed to have more potential than others for providing ancillary services as demonstrated by examples of various operational projects in this study Source: CES/IESA Internal Analysis
Energy Storage Price Trend Last 3-4 years have witnessed rapid reduction in prices in energy storage technologies due to the increasing commercialization and manufacturing scale up. India could accelerate this trend by providing a huge market for such technologies. Introduction of ancillary service requirements in a technology neutral manner will accelerate such localization efforts and will help in bringing down the costs further. However, working of levelized cost of ancillary services may indicate that some of the technologies may require additional financial support during initial deployment phase for 2-3 years. Source: CES/IESA Internal Analysis
PGCIL- Energy Storage Pilot Project Overview Powergrid Corporation of India ltd. (PGCIL) has already announced a tender for 2 demonstration projects at Puducherry for demonstration of LI-Ion, Advanced Lead Acid for frequency regulation in 2015. This project is under implementation phase now. This project is being carried out to find suitability of battery technologies for grid scale storage system in India for grid ancillary services to facilitate renewable integration Open RFP by PGCIL: for NaNiCl2 / Alkaline / Flow battery Supply, Installation, Testing and Commissioning of Battery Energy Storage System using: Energy Storage Size: 1 MWhr Primary Application: Frequency Regulation Last Date to Apply : 24 th March 2016
Recommendations Initially, some more demonstration projects may be set up under the ownership of transmission companies and operated by State/Regional Load Dispatch Centers as these agencies may operate such assets in an unbiased way and may keep grid security as only priority. Need to introduce frequency regulation as well as synchronous and non synchronous reserves for managing grid reliability and quality. Frequency regulation requirements should be based on peak load and renewable penetration Regulations should have a clear roadmap for deployment of ancillary services under various scenarios (with storage options), which can provide clear investment signals for potential project developers and technology developers. There is a need for proper enforcement for procurement of ancillary services. Failure of enforcing ancillary service procurement and payment mechanism could create significant hurdles.
THANK YOU Contact: Mr. Debi Prasad Dash Manager : India Energy Storage alliance (IESA) Sr. analyst, Customized Energy Solutions Email: ddash@ces-ltd.com, contact@indiaesa.info