By Ramanuj Yadav, Energy Auditor, Larsen & Toubro
Ramanuj Yadav, Energy Auditor, Larsen & Toubro
“Saving energy is like the generation of energy”. In today’s industrial and domestic sectors, efficient utilization of energy has come up as an urgent need. To save energy one has to utilize & monitor the energy carefully.
The Objective of this article is to assess the potential of energy saving by energy consultants and achieve it through a systematic way, thus bringing down energy per unit of production to the lowest. Efficient usage of energy assists to increase productivity and product quality, in turn improving reputation with customers and society keeping environmental protection.
A well-organized approach to maximize and achieve energy efficiency should start with a combined interaction followed by Techno-economic evaluation. After evaluation the implementation decision must be supported by an action plan defining savings achievement steps and a system to measure energy savings. During combine kick-off evaluation meeting; energy consultant should review all energy systems & equipments for its operational efficiency, energy economy & maintenance schedule. During plant visits discussions should be held with engineering, maintenance and operations team to evaluate working methodology, with a clear understanding of working, the consultant based on the data collection & measurements should perform trials to explore applicable equipment and systems saving proposals from electrical and thermal standpoint.
An energy consultant should explore all equipment and all thermal and electrical systems installed in plant. Typical equipments systems installed in plant are compressors and compressed air system, steam boilers, cooling towers and water distribution system, sewage and effluent treatment plants, electrical distribution and consumption, HVAC system and auxiliaries, water pumps, fans and blowers, fuels and fuel handling system, humidification system, lighting system, load factor improvement, manufacturing process and equipment, material handling system, motors and motor controls, captive power generation system, power factor improvement, process water and hot water system, refrigeration system, vacuum system, waste management system and many other areas as per the client expectations. For inspecting and checking the operating parameters of various thermal and electrical utilities energy consultant must be equipped with all necessary pre-calibrated instruments and devices like flue gas or combustion analyzers, power masters for both single and 3-phase, clip-on power factor meters, data loggers, ultrasonic leak detectors, vane anemometers, manometers, digital humidity meters, Light (Lux) meters, Tachometers etc..
By analysis the metered and collected data, energy consultant will perform the basic calculations for identifying the existing running efficiencies of various utilities and furnish the energy audit report. The report should comprise of the specifically identified energy saving proposals, energy management organization structure, Energy Accounting and any other information specific to the company. Energy Consultant’s role is to act as a catalyst assisting implementation of energy savings proposal. Energy consultant must spend adequate time in identifying, discussing, crystallizing and presenting savings proposals with all details and ready to roll for implementation. It is the joint effort of client and the consultant which will result in monetary savings.
The role of consultant apart from the independent assessment of energy savings is also to complement in-house efforts which may result in energy conservation. In areas, where savings have already been considered by client, the consultant will provide an independent appraisal to accelerate pace of progress. This study will be conducted with minimal interference to the normal activities of the plant. The energy consultant must ensure, while conservation of energy is important, it should not be at the expense of safety, quality, production or employee morale. The building blocks of a successful energy conservation audit at Client premises should be an integrated approach though online monitoring & control with guaranteed savings.
The first step in developing any savings proposal is approval of the concept. This is not feasibility but a concept to prove or disprove. This is to avoid any ambiguity between client and the energy consultant in developing a proposal. Afterwards, consultant should establish base case data of existing operating parameters from questionnaire, specifications, data log books, direct measurement, observations and discussions with plant personnel at all levels.
For establishing base case data the consultant should perform various investigations like measurement of power readings, fuel flow, operating hours, configuration, comparison of design v/s operating parameters, peak and lean period usage etc. The consultant must review major systems and equipment consuming energy for operational efficiency, energy economy, and maintenance. Before leaving the site after site data collection & measurement activities, consultant should review the saving opportunity concepts and validate the base data with approval and confirmation from responsible authority of the plant to establish the monitoring & verification protocol. The energy saving proposals recommended by the energy consultant should comprise of the description of present and proposed system, validated base data by the Client, method of calculating savings, method of measurement and verification of savings after implementation, vendor performance guarantees whether the proposal can be implemented technically.
Financial feasibility is the final stage of the approval process which involves vendors to obtain offers for equipment and services as required. The vendor quotations and life cycle cost of implementing the proposal will be presented and the financial viability will be established. Each recommendation comprises of a full description of saving opportunity, estimate of potential savings, method to implement savings, estimate of costs where investment is involved, special technical information as required to facilitate implementation and usage of proprietary computer software. The energy consultant should help client in developing a framework for an online monitoring and control system to ensure Specific Energy Consumption (SEC) gets constantly and dynamically controlled. This means management will be able to take proactive and online corrective action when there is an adverse variance in SEC. Thus the cause-effect relationship of the main factors that affect SEC will be modeled.
The integrated approach of any energy audit program would be implementable and measurable saving proposals. All proposals developed by the energy consultant should be tried and tested ones. Implementation of these proposals would yield measurable results & must be financially & technical feasible. The energy consultant must have specialist attention, concept generation ability, detailed techno-economic viability and other company’s energy saving projects implementation experience. The energy consultant can assist the client achieve sustained energy savings through a well-organized and planned systems approach. Even though energy consultants who do not implement this kind of approach will also benefit since there will be no ambiguity in the savings proposed by them.