Energy Efficient Drives - an integrated approach to Energy saving, Excerpts from a Workshop - India Renewable Energy Consulting

For the past two years, I had been keenly observing the energy efficiency space, for two reasons:
1. Energy efficiency facilitates a migration to a more sustainable world as much as, or even better than, renewable energy sources
2. The paybacks for energy efficiency projects are much better than what they are for most renewable energy projects

I had attended an interesting workshop on Energy Efficient Drives – an integrated approach to Energy saving on 8th March 2014 at Chennai.

Energy efficiency has been a topic I have been drawn to last couple of years owing to its enormous potential to lead us to a sustainable energy future.

But my knowledge of industrial energy efficiency has been quite patchy. To a certain extent, I could say that this workshop provided clarifications.

Am providing brief summary of what transpired and snapshots of lots of slides.

Audience comprised mainly the following

Energy Managers and Auditors
Factory Operators
Maintenance and Energy Engineers and Managers
Consultants and Application Engineers and Managers

Presentation on Energy Efficient Motors

Presentation on Energy Efficiency and Compressors
Presentation on Variable Speed Drives and Energy Saving
Energy Efficient Pumping Systems
Presentation on Energy Efficient Fans and Blowers

Some bullet points

Industrial motors, transformers and air conditoners alone contribute significantly to energy consumption
Star rating available for industrial motors
India also adopted energy efficient industrial motors since 2011
68 lac motors produced, 99.8% LT motors?? Is this for India alone?
100s of seminars have been conducted on energy efficient industrial motors in India
Motor energy saving calculator available on International Copper Association web site (available from www.copperindia.org)
TVS Group energy efficiency motor calculation available in the iPad snap
Different countries have differing energy efficient motor standards
Higher efficiency means more motor, more motor means higher starting current
Industry should take much higher care while selecting and maintaining motors
Siemens representative spoke energy efficient switchgears
Godrej representative spoke on Compressors
Running cost of a compressor per year is four times the purchase cost
Pressure not stable at various stages of a compressor, Godrej compressors maintain constant pressure
Blowers
Turbo blowers – higher end
Latest – twisted, trilobe blowers
Overall, 40% efficiency possible from the lowest end of the blowers to the highest
Compressors
“Air is free, compressed air is costly” says Kannan
VFD presentation by Danfoss representative
represented by Techno Products, enhancing VFD’s productivity
Drive has fewer components
Drive used as a pum
For some of their HVAC drives, building management systems can be avoided
Energy savings – cooling tower automation, payback period – 10 months
Significant power savings for refrigeration using VFDs
3 levels of coating are available. Their drives can even survive harsh environments
Gap between drives can be very small
Energy saving cooling design – talks a lot about lot of heat being taken before the panel room, but not sure if that heat is used anywhere
One expert said harmonics is a big issue
Entex – Mr Reddy, Energy Efficient Pumping Systems
Most guys just say 5 HP pump, but they should also specify other parameters for the pump
At 100% flow, efficiency is the highest – 75-80%
Many times, pumps could be overdesigned or underdesigned
If overdesigned, pump will flow at a higher flow rate, then need throttle and decreases efficiency
Another way to run an overdesigned pump will be to use a VFD or trim the diameter
VFD is not a great idea for fixed flow systems
HVACs and chillers could require variable flows and hence VFDs
Between trimming and throttling, trimming could be better than throttling
Gave an eg where an ad hoc replacement ended with a 10 HP replaced for 5 HP temporarily, but the 10 HP continued even after the 5 HP had been repaired, and when they had to finally replace the old 10 HP, was replaced by a 10 HP.
Benet George from Schneider Electric
Spoke on VFD applications in industry
VFDs only where there is significant variance in loads
VFDs can also do thermal savings?
Other options instead of VFDs – resizing, trimming, multiple pumps, stop/start
Carpet manufacturing – 2 HP, payback period was a few days
Efficient fans and blowers – VFDs cannot do anything about the inherent inefficiencies in fans and blowers