HP Innovation Journal Issue 09: Spring 2018 | Page 56
Technology for Everyone
Figure 2: Destruction of Available Energy
As another example, consider hydro-electric power
generation as a supply side source powering electric vehi-
cles. In this case, as shown in Figure 2, available energy
is the potential energy in water at the height of the dam.
This available energy undergoes multiple conversions to
become electric energy at the power plant. At every pro-
cess, and every conversion stage in the dam, available
energy undergoes some level of destruction. And, fur-
ther destruction occurs in transmission and distribution.
A fraction of the available energy that was available at
the height of the dam makes it to the charging station.
The electric charging station charges the batteries in the
electric car—another conversion step that leads to fur-
ther destruction of available energy. The available energy
stored in the batteries in the car and is used to propel the
car. The available energy in the batteries is converted to
kinetic energy and waste streams during propulsion of the
car. The recovery of some kinetic energy during braking
is a superb example of recovery of available energy from
a waste stream.
One of my colleagues elegantly described the destruc-
tion of available energy as an hourglass with the grains of
sand continually flowing from one half to the other. We
cannot slow it down and, alas, we cannot refill it. We have
the potential to slow the process by getting the most that
we can out of every single grain of sand, or unit of avail-
able energy in our case. The world cannot wait.
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A Fundamentals-Based Framework for Sustainability
Given the global pool of available energy, from a portfolio of
sources, the following systemic framework articulates the
principles by which we can devise sustainable ecosystems.
On the supply side:
• Minimize the available energy required across the life-
time of a product by accounting for available energy
required for extraction, manufacturing, waste miti-
gation, transportation, use, disposal and reclamation.
• Use local sources of available energy to minimize the
destruction of available exergy in transmission and
distribution (e.g. build local micro grids of power from
local sources such as wind, solar, manure, municipal
and sewage waste, etc).
• Take advantage of available energy in the waste
streams (e.g., exhaust heat from a turbine); The use of
regenerative braking is a good example of utilization
of waste streams.
On the demand side:
• Minimize the consumption of available energy by pro-
visioning resources based on the needs of the user by
using flexible building blocks, pervasive sensing, com-
munications, knowledge discovery, and policy-based
control systems.