Environmental Engineering Reference
In-Depth Information
5 ImprovingEfficiency
EFFICIENCY AND SUSTAINABILITY
Efficiency and sustainability are often used as synonyms. Many companies and individuals
believe that by starting initiatives on energy saving or becoming more efficient in the use of
resources they are “sustainable.” Sustainability and efficiency are not interchangeable terms;
however efficiency is an important stepping-stone in the pathway to sustainability.
Increasing efficiency is normally a short-term approach that is fundamentally based on the
return on an investment. High efficiencies in most cases decrease operational costs. This is the
easiest step because even if requires capital expenditure there is most certainly a return on the
investment in a relatively short time. However, increasing efficiency is just doing “less bad”
(McDonough and Braungart, 2002) and does not solve the sustainability issue because more
needs to be done to create a sustainable system.
As discussed in Chapter 1, long-term sustainable operations are ones that produce
minimal impact on the environment and can perpetuate themselves by using renewable
energy and resources; which is not the kind of systems we have in place today. If current
practices are not changed, the economic system will come to a stop as a result of the
depletion of natural resources, lack of affordable energy, climate degradation, and excessive
environmental pollution. Ideally, that change would come with the replacement of today's
totally unsustainable system with a 100-percent sustainable alternative. However,
realistically speaking, this transition can not be done without going through a progression
of steps and following what in this topic is called the
sustainability
staircase
(Fig. 5.1).
This sustainability staircase consists of a series of steps in which each one is a contribution
toward the attainment of a sustainable process or system; however, these steps do not
represent sustainability by themselves. Each flight of steps is a major improvement in
transforming the unsustainable system into a sustainable one. Each riser represents one
improvement toward the total burden; and the treads are intermediate levels toward the
ultimate goal.
The first step in the sustainability staircase is “increasing efficiency.” This step involves
reduction in the inputs such as energy, raw materials and water, and minimization of the out-
puts such as atmospheric emissions, solid waste, and wastewater. Reduction of gas emissions
normally comes as a consequence of increasing energy efficiency.
Improving efficiency can be directed to the product, the process, buildings, supply chain,
distribution chain, and so on; and these efforts are not a one-time action rather they are a
