Continuing our discussion on energy management initiated on ‘World Environment Day’, in this issue of e-power, we interview Dr. Kushare, to bring to you some practical insights on the subject.
Dr. Kushare is a Phd. (Electrical) form Govt. College of Engineering, Pune and currently the Head of Electrical Engineering Department K.K. Wagh Institute of Engg. Education and Research. A certified Energy Auditor of BEE (2004 Batch), he regularly presents research at conferences, workshops and journals dedicated to electrical field within India and other countries. He has also authored several technical books on the subject along with a Handbook on Energy Efficient Motors.
Dr. Kushare advises companies on energy management and audit, power quality audit and critical problem solving. As a consultant he has also designed electrical installations of several industrial and commercial establishments in India and abroad. His expertise in energy efficient and power quality tolerant designs and low investment driven approach to energy management is well acclaimed.
Dr. Kushare, HOD, Electrical Engg. Dept., K K Wagh Institute of Engineering
With such a broad scope and a huge range of opportunities for its applications, how does one define ‘Energy Management’?
Dr. Kushare: Energy management is defined by one guiding principle which is ‘judicious’ and ‘effective’ use of energy without compromising on the technical requirements for minimization of energy cost and maximization of profits. These two aspects are important yet mostly ignored.
Why do you say that ‘judicious’ and ‘effective’ aspects are ignored?
Dr. Kushare: Simply because there is little evidence to believe that our design, operations and maintenance are judicious or effective in terms of energy usage. Being judicious begins right from the design stage. Firstly, loosely defined system requirements are a problem. With vagueness in requirements system remains non-optimized and ironically, programmed to waste energy.
Secondly, overdependence on thumb-rules for design is fatal to energy management. Many times safety margins in design are kept at 30% to 50% more than the ideal. In fact one should aim to achieve 10% to 15% safety margins, through use of innovative techniques and latest technology.
Can you elaborate with some examples?
Dr. Kushare: Sure. For example, I have observed that typically, the induction motors in process industry have a service factor of 50% to 60%. In most cases designer is not given adequate inputs, lowering designer’s confidence and inflating factor of safety. Also, users many times forcefully build an overcapacity in design with a view to accommodate any future expansion.
Today, we need to adopt innovative modular approach in design which has the flexibility to scale up with change in requirements.
A relatively common example in this context would be the approach taken to design Air conditioning or lighting systems. Rule of thumb based calculations do not include factors like environmental conditions (temperature, altitude, window directions etc.) which can be intelligently turned to ones advantage during design for saving energy. Being judicious is about being responsible – it’s the ability to arrive at what is enough and avoid the trap of over sizing or creating over-capacities.
Further to the definition of energy management in your answer to the first question – Can you elaborate on ‘effective’ use of energy?
Dr. Kushare: Effectiveness is a measure of conversion of energy from one form to another. Procuring energy efficient gadgets is the starting point (and not final destination as often perceived) in energy management.
In procurement, the objective is to save costs upfront and go for cheaper option while overlooking the ‘use costs’. For example, an industrial motor with 84% efficiency running for 3,000 hrs pa with a life of 15 years has operation costs of about Rs. 85 Lacs and initial costs of just Rs. 1 to 1.5 Lacs. Being energy effective is about achieving the breakeven between technical performance and commercial capabilities. Also, the focus needs to shift from initial costs to lifecycle costs.
What do we need to consider while assessing ‘life cycle costs’?
Dr. Kushare: Life cycle cost has two major components, energy costs and maintenance costs. While energy costs are largely a determinant of equipment efficiency, maintenance costs play a key role in sustaining these efficiency levels.
Often it’s the small changes that bring the big impact. Take for example, auxiliary equipments like cooling fans. These, typically, have a Windage loss of about 2% of rated capacity. Now, if you can minimize this loss over all such fans, the overall savings could be significant. This loss is related to weight and speed of the fan. Fan that is of metal die-casted type has more weight and hence greater loss. But a FRP fan with its smooth profile and light weight will be more efficient. Energy management in such cases is nothing but applied commonsense. (To be Continued…)
In the next issue of e-power we discuss with Dr. Kushare on the implementation challenges in energy management, current status of awareness and penetration of energy management techniques in various industries and the future outlook of the subject….
