Electricity demand side management and end use efficiency
ELECTRICITY DEMAND SIDE MANAGEMENT AND END USE EFFICIENCY D. Pawan Kumar
PRESSURE POINTS OF CONTEMPORARYELECTRIC UTILITIES: Peak demand and energy crisis in many utilities due to ever rising demand supply gap Need for optimization of generation and network utilization Regulator led energy efficiency mandates Strong lobbying from environmental groups Resource constraints and customer demands for cheaper rates Increased operational flexibility needs Competition, thanks to reform process and open access
TRADITIONAL UTILITY PLANNINGPROCESS, NEEDS & TOOLS Load Need to Predict & Provide for: forecasting Long Term Planning More Lead timeGeneration Rising Costs Planning Environmental ImpactsProduction Supply side alternatives Costing Capital Costs Fuel costs Other O& M costs Financial Analysis Iterate as Tools: Least Cost Planning necessary & Rate Allocation Demand Side Management
LEAST COST PLANNING: “How much energy efficiency could we achieve if all the potential end-use energy efficiency were achieved which is economically competitive with conventional forms of energy”--- Roger Sant W. -- The Energy Productivity Center Four basic steps of Least Cost Planning(LCP)are: Understand how energy is used (end-use energy) Identify technical potential of high end-use efficiency Evaluate the benefits and costs from societal perspective Apply engineering & economic analysisIntroduced to persuade energy planners & policy makers that thereis sizeable potential to improve EUE with following considerations •Customer & Utility Considerations •Program Implementation •Financial commitments involved •Monitoring & Evaluation
WHAT IS DEMAND SIDE MANAGEMENT ?“DSM is planning, implementation & monitoring of Utilityactivities designed to influence consumer use of electricity inways that will produce desired changes in the magnitudeand pattern of load either directly caused or indirectlystimulated by the utility.” ---Clark W. Gellings, Electric Power Research InstituteBroad purview of DSM will influence customer use must achieve selected objectives should be evaluated against non - DSM alternatives identify customers response evaluation process • Load ManagementHow to achieve DSM? • End Use efficiency Improvement • Development & Promoting EET’s.
DSM LINKAGES-INDUSTRY SECTOR Industry sector Utility Load potential End DSM DSM Implementation Shape Uses Technology Methods Objectives Options Alternative Peak Clipping pricing like TOU tariffs Valley Filling P.F and LF Improvement Regulatory Load Shifting measures Lighting system Strategic Process utilities Specific menu of Incentives for Conservation energy efficient EET’s Process technologies to Strategic Load modernization Energy Service match each end Growth Drives Companies use option promotion FurnacesFlexible Load Devices & controls Designing Shape customized DSM programs
DSM FRAME WORKDSM OBJECTIVES DSM ALTERNATIVESDEFINED/REDEFINED IDENTIFIED DSM PROGRAM DSM EVALUATION MONITORING & SELECTION DSM PROGRAM IMPLIMENTED
BROAD OPTIONS AND TECHNOLOGIESFOR INDUSTRIAL DSM Tariff and revenue related Static metering, reactive power billing, maximum demand charges, TOU tariffs, incentives etc. Low /medium cost technical retrofits in: Plant/Process utilities, drive side modernization ,furnace controls and automation. Illumination system improvement options including: LEDs, CFLs, low loss ballasts, microprocessor based controls, high efficiency reflectors etc. New plant / large capital measures Process r & m, retrofits, adoption of distributed controls, automation etc. Energy Management Techniques monitoring & targeting, EM staff training & motivation, mandating and sponsoring energy audits
EVALUATION OF DSM OPTIONS As seen from the above, various identified end use efficiency,DSM measures, offering energy and demand saving opportunities qualify to be assessed for supply side impact, benefits and costs,(as cost of saved capacity and cost of saved energy).The results relate to local utility attributes and considerations . These are then compared with alternative, corresponding, supply (utility) side costs of capacity addition and long run marginal cost of generation. Only those options of DSM are shortlisted, which are cheaper than supply side costs. To arrive at cost of saved capacity CSC,and cost of saved energy, following relations, criteria can be adopted.
RELATIONS AND CRITERIA…..» Capital recovery factor (CRF) = d × (1 + d)n / [(1 + d)n - 1] where d = utility discount rate & n = measure life» Total DSM measure cost = initial cost × [ 1 + (1/(1+d/100)m) + (1/(1+d/100)2m+ …...) where d = utility discount rate & m = device life & the series includes all terms where exponent is less than the measure life» Cost of saved capacity (CSC) Rs/kW or Rs/kVA= (Total measure cost (Rs)) ((Saved capacity kVA or kW × PCF) / (1-TDLF) (CUF))» Cost of saved energy (CSE) Rs/kWh= (Total measure cost (Rs) × CRF) (Annual Energy Savings (kWh))
…...RELATIONS AND CRITERIA T & D loss factor of local HT & EHT segment for measures relates to HT or EHT segment end use = TDLF (HT) T & D loss factor of local LT segment for measures relates to LT segment end use= TDLF (LT) Capacity utilization factor (CUF)is also PLF of the local power plants.(A low CUF say in hydro power plants as against base load thermal plants can influence measure cost benefits) Peak Coincidence Factor (PCF), indicates proportion of the end use equipment actually operational, during system peak hours. Utility discount rate, is denoted here as, d. Each DSM measure cost is assessed for a measure life of 25 years, for parity with considered utility plant life in account books, and equals the net present value of measure cost for 25 years of measure life where m is number of replacements within 25 years, and d is the discount rate.
NEXT STEPS IN DSM PROCESS: Analyze and merit rate each of the choices, where the cost of saved capacity & cost of saved energy of DSM measure is less, as compared to cost of capacity addition and long run marginal cost of generation(being utility side SSM costs). Once all the DSM interventions are merit rated, the logical next step is the development of Detailed Project Reports and plans for implementation of short listed DSM interventions, in a programmatic manner, adopting a standard project management cycle.
ILLUSTRATIVE CASE STUDY OF DSM OPTION EVALUATION…..(APPLICATION OF LIGHTING VOLTAGE REGULATORS INMUNICIPAL WATER PUMP HOUSES) The Fluorescent tube manufacturers list the rated or nominal wattage on any given tube as the objective wattage which the tube should dissipate under prescribed conditions of operation. The actual wattage, invariably higher, however depends upon factors such as supply voltage. A lighting voltage controller operates on the well known principle that reduction in input power can be achieved by voltage optimization without significant drop in light output. A typical device operates by bringing in, an impedance across the lighting circuit, to control supply voltage and current. The lighting voltage controllers are modular in configuration and can be used on lighting circuits and are applicable for Sodium Vapor and Mercury vapor lamps as well. Based on end user feedback, Energy Savings of 10% and Demand Savings of 15% are envisaged through application of the Lighting Voltage controllers.
….APPLICATION ANALYSIS RESULTS IN A MUNICIPAL WATER PUMPING STATION……Lighting System kW Load = 24PF of Lighting circuit = 0.85Lighting system kVA Load = 28.2Hours of annual operation = 8760 (indoor application)Peak coincidence factor = 1.0Utility discount rate = 0.09End User Electricity Cost = Rs.2.46/kWhDemand Charges = Rs.170/kVACapital Recovery factor = 0.102 Transmission and Distribution Loss Factor for HT Industry (TDLF) = 0.3132Capacity Utilization Factor (CUF) = 0.725Energy Savings (kWh) scope = 10%Demand Reduction (kVA) scope = 15%Investment in Rs/kVA rating = 1800Measure Life, Years = 25 YearsDevice life, hours = 100,000 Total Measure Cost = Rs.71,144 ,being initial investment + discounted costs offuture replacements over measure life period
…END USER COST BENEFITS…..Present annual energy consumption kWh = 181332 Annual electricity savings, kWh@ 10% = 18133Annual Demand savings @ 15% = 4 kVA * 12 months Rupee value of annual electricity (kWh) savings = Rs44608 Rupee worth of annual demand (kVA) savings = Rs8160Total annual savings = Rs52768 Investment for lighting controller (Rs.1800/KVA*Lighting system kVA Load)= 50800Simple Payback Period Years =(Investment/Rupee value of annual electricity cost savings)= less than 1 year
…..SUPPLY SIDE COSTS.Cost of Capacity saved (CSC) in Rs/kW=(Total Measure Cost (Rs.)) / ((kW Capacity Saved*PCF)/ (1-TDLF)(CUF))= (71144) /((2.4 * 1)/ (1-.3132)( 0.725))= Rs. 14760 / kW Cost of Energy Saved (CSE) in Rs. /kWh= (Total Measure Cost(Rs.)*(CRF)/(Annual Electricity Savings in kWh)= (71144 * 0.102)/(18133)= Rs. 0.40 / kWhThe end user simple payback period of less than 1.0 Year, alongside attractive utility sidecosts of Rs. 14760 per kW saved capacity ,as against utility side cost of Rs 40,000 per kW ofcapacity addition; and, Rs0.40/kWh cost of saved energy, as against Rs 2.00/kWh averageutility cost of supply, render the DSM measure a win-win option.The state Utility / DISCOM could develop a DSM program for all municipal pump housesin its coverage area and incentivize stakeholders suitably.It may be appreciated that a well designed DSM program can address energy efficiencyimprovement at macro level, considering all local factors. Analytics in an iterative manner, for sensitivity factors like peak coincidence factor,TDLF,CUF, discount rate, can be attempted for customized, localized, program design forvarious options.
GENERIC DSM MEASURES IN LOADMANAGEMENT, PROCESS/PLANTUTILITIES IN INDUSTRY SECTOR… Power factor improvement Application of VSD’s, cogeneration etc, for EE Conventional ballasts on FTL’s replaced by low loss Replacement of old compressors, ballasts chillers, by energy efficient compressors, chillers. Adoption of energy efficient CFL’s/LEDs ,Magnetic Distribution system upgrades in induction lamps, LPSV, HPSV water pumping, compressed air, lamps… chilled water systems for EE Adoption of Lighting voltage Material handling system upgrades controllers for EE. Motor Soft starters/Energy Adoption of distributed control savers adoption systems, process automation for EE Replacement of old pumps by Furnace, heater upgrades for EE. high efficiency pumps Replacement of old rewound motors Replacement of old fans by by new high efficiency motors. high efficiency fans motors………
BARRIERS TO DSM… Limited Information & Awareness Lack of adequate infrastructure Perceived risk of implementing new EE technologies Absence of codes/standards on EE. Lack of reliable and credible service organizations that can provide full range of project implementation services Limited Availability Of Capital for financing EE Projects High costs for consumers to implement EE projects Administered energy tariffs which distort economics. Absence of any regulatory mandate to review all options on DSM & Supply Side Management to develop a least cost capacity expansion plan
….BARRIERS TO DSM Problems with quality of power Lack of experience in planning, designing & implementing DSM programs Absence of load research information, databases on energy end use segments, reliable data on peak coincidence factors etc. Lack of resources specifically allocated for EE Lack of adequately skilled staff to initiate EE measures Inadequate participation and attention from Govt. and policy makers….
ENABLERS FOR DSM MARKETS – AWISH LIST: Regulators and utilities start introducing the concept of LCP,DSM in the power sector planning frame work Developing nations initiate programs on EE in electricity generation, transmission, distribution and industry sectors Developing nations initiate design and adoption of appropriate energy conservation laws and regulations, efficiency standards & labeling, rational electricity pricing and incentive schemes for EE Regulators and utilities initiate regular load research and development of customer databases on energy use and efficiency improvements for analytics and planning. Promotion of energy conservation through mass media - based awareness campaigns
CONCLUSIONS DSM is a viable, win-win cost effective alternative to SSM. There is a good case for DISCOMs to develop customized DSM programs for end users like industry clusters, agricultural pump sector, municipal water pumping, street lighting, PSU townships, industrial estates, special economic zones, commercial buildings etc., due to diffused yet significant bulk nature of these end user entities and energy efficiency margins. •DISCOMs may also consider developing customized DSM programs, involving distribution upgrades, automation, kVAh billing, static metering, TOD tariffs etc, to bridge demand supply gaps efficiently, without revenue losses. Current crunch times at utilities call for load research and comprehensive re-visit to various end use segments for structured DSM program design and implementation, which could be highly cost effective, as against supply side capacity augmentation initiatives.