Green Manufacturing Technology Wedges

The last blog looked at the complete product life cycle to see the breadth of manufacturing  - from material extraction through production and distribution to end of life. We want to drill down a bit more on the production phase of that cycle.

In my lectures discussing green manufacturing I often use a “Google earth view” of manufacturing to zoom in from the enterprise level to the lowest levels on the shop floor – each step increasing the level of detail shown and, consequently, exposing more opportunities for improvement. (In fairness, this was originally the idea of one of my recent grad students – Athulan Vijayaraghavan). It’s a great analogy.
We’ve all used this feature on Google – put in a destination and with rotations and magnification the desired address moves into clearer and clearer view until we are staring at our destination with startling detail.

Same thing for manufacturing. We can start at the factory/enterprise level – move in closer to the production floor, then to the machine lines, on to individual machine tool, down to the spindle and table, and then, finally, to the tool-material cutting zone. (I’m a machining person by training so my analogies usually use metal cutting! But, this works with any enterprise to process zoom.) A representation of this zoom is below.

The interesting thing is that, if you look more and more closely, you see the many areas for “greening” the process. It’s like a tide pool at the ocean – you stare into it and there seems to be nothing there. But, bit by bit, you see little creatures moving around and, finally, are amazed at how much life is in that little pool.

I like to refer to these opportunities for greening as “technology wedges” after a concept proposed by Pacala and Socolow to address the big gap between the present trajectory and impact of CO2 on the atmosphere (business as usual – BAU) and a sustainable level – and how to close this gap in 50 years. (The full citation is “Stabilization Wedges: Solving the Climate Problem for the Next 50  Years with Current Technologies,” Science 13 August 2004: Vol. 305. no. 5686, pp. 968 – 972.) They reason that, rather than trying to find one “silver bullet” to correct this increasing mismatch between what we need and what we are doing, we should concentrate on “technology wedges” – small advances and improvements that, when added up, have the effect of a large change in the way we do business. 


Their wedges include efficiency improvements, carbon capture and storage from power plants, renewable power, etc. The specific wedges they propose are not the main interest here. But, the idea has real merit.

If we look closely along the view from enterprise to cutting tool, as in our zoomed view, we can see many opportunities for green technology wedges. Some are simple improvements. Others are more substantive and may require new technology or, for the entrepreneurs, offer opportunities for new businesses.


A complete discussion of this concept is in a paper I co-authored in 2007 (Technology Wedges for Implementing Green Manufacturing, NAMRI Trans., 35, 2007, pp. 193-200 – if you want a copy send me a note.)

In that paper we proposed a set of rules for applying technology wedges for green manufacturing:

1. the cost of materials and manufacturing (in terms of energy consumption and Green House Gas (GHG) emissions, etc.) associated with the wedge cannot exceed the savings generated by the implementation of the wedge (or wedges) over the life of the process or system in which it is employed.
2. the technology must be able to be applied at the lowest possible level in the process chain.
3. the cost and impact of the technology must be calculable in terms of the basic metrics of the manufacturing system and the environment. That is, cost and impact must be expressible in units of dollars (or euros, yen, yuan, etc), carbon equivalent, global warming gas creation or reduction, joules, cycle time and production rate, quality measures, lead time, working capital and so on relative to present levels of consumption, use, time, etc.
4. the technology must take into consideration societal concerns along with business and economy, and
5. there must an accompanying analytical means or design tool so that it can be evaluated at the design stage of the process or system. It must be an integrated approach.

These are general rules that should be considered when evaluating green technology solutions (wedges). Since the paper was written some refinement of these basic rules could be added but, overall, they are applicable.

I’ll include some applications of this approach to manufacturing systems in the future. In the meantime – take a close look at your product life cycle, or production system and processes, to see where green technology wedges can be implemented.

A reminder - "Why Green Manufacturing?" Join my webinar on September 17th - go to

https://www2.gotomeeting.com/register/187277227 to register.