V. CONCLUSION
Power electronics is a key technology for a sustainable electrical
energy future. Alongside renewable energy sources and
energy efficient loads, power electronics is an enabler in sustainable
energy systems which provide energy for the full life-cycle
of electrical loads, including the energy for manufacturing and
end-of-life management as well as the energy for their operational
cycles. It is shown in this paper that power electronics can
significantly reduce the time to achieve the sustainable energy
balance of such systems.
The concept of energy payback time of power electronics is
introduced in this paper and can be used as a powerful tool to
quantify the contribution of power electronics to sustainability.
From the life-cycle analysis performed on two power electronics
converters it can be seen that the energy needed to manufacture
the converters is practically negligible compared to the
energy saved by introducing these converters in motor drive systems.
This translates into a short energy payback time of power
electronics.
From the presented case studies obtained it can be ascertained
that the energy payback time of adding power electronics
is in the range of a few months. In most cases this is considerably
shorter or at least comparable to that of renewable energy
sources (wind turbines 6–8 months, PV systems 1–3 years).
Yet, the renewable energy sources are well known to the general
public for their “green” epithet while few know about the
energy savings potential of power electronics. The concept of
power electronics energy payback time can be used to positively
influence this perception. Since the implementation of
power electronics has a multiplying effect (see Table II), this
figure of merit can also be used as a powerful tool in illustrating
the value of power electronics to both policy makers and the
general public. This will help power electronics move forward
and realize its full potential toward the sustainable energy future.
Looking at the complete energy life-cycle picture of the presented
two converters, it can be concluded that the energy dissipated
through losses during the converter’s life is an order of
magnitude larger than its embodied energy. Thus, further improvements
in the total energy footprint of the converter should
come from increasing the converter’s conversion efficiency and
only when this value is increased by a couple of percentage
points compared to today’s typical values will the embodied
energy represent a significant part in the total picture.