Page 25 - Renewable Energy Devices and System with Simulations in MATLAB and ANSYS

12 Renewable Energy Devices and Systems with Simulations in MATLAB and ANSYS ®
®

In one approach, electricity from the AC grid or renewable resources is used to produce hydrogen
using an electrolyzer system. The hydrogen can then be stored at high pressure and used for fuel cell
systems, such as the one schematically depicted in Figure 1.13. In principle, provided that suitable
infrastructure would be in place for hydrogen, a large variety of consumers, both stationary and
mobile, can be supplied.
The other approach relies on the use of batteries for which chemistries continue to be developed
and perfected such that energy density and lifetime are increasing, while the cost is decreasing. With
the use of bidirectional power electronics converters in the battery-based system from Figure 1.18,
the electric energy can flow both from the grid to the battery and in the opposite direction, and the
functionality can include active grid support and stabilization.

1.4 CHALLENGES AND FUTURE TRENDS
Table 1.1 summarizes the research challenges and opportunities and future trends over the next 10
years to 2025, alongside the present status for the main renewable energy technologies. Sources of
information include references such as [16–23]. General expectations are that through technological
improvements, the renewable energy devices and systems are expected to become even more cost
competitive with fossil fuel–based generators.
Apart from the particular technologies, systems, and devices that have been previously described,
a special note is due to the substantial ongoing efforts for integrating renewables into the power sys-
tem, where a proper balance between production and consumption exists. Being able to control the
entire energy system as a whole, including not only the electrical power system but also the thermal
energy and the water flow, is also an ongoing challenge for research and the society. In this context,
the smart grid functions and their facilities, such as communications, load control, and energy stor-
age, are seen as solution enablers.

1.5 FURTHER READINGS
With such wide interest over the last decades, the literature on renewables is very rich and many new
journals are coming up in the field. The long list of books, which focuses on electrical engineering
aspects, includes those listed as references [24–28]. Examples of overview papers published in jour-
nals and magazines are listed as references [28–40] in this chapter, but they continue to be expanded
as renewables are getting more and more important.
The Electric Power Components and System journal has recently (2015) published a triple spe-
cial issue, 43(8–10), devoted to timely research on renewable energy devices and systems. This
includes more than 30 papers from across the world. Power system topics comprise distributed
generation and system integration with solar PV and other renewables, microgrid configurations,
and optimal controls. Alternative topologies are presented for PV converters and system installa-
tions together with MPPT algorithms. The ongoing research on wind turbines and farms is illus-
trated by reports on special and conventional electric generators and power electronic converters,
reliability, specific controls, and issues related to offshore installations. Energy storage studies
examine systems employing batteries, flywheels, and fuel cells. Also included are papers on the
control and life cycle of wave and tidal energy generation systems and two reviews reporting
on the current status, recent developments, and future trends in China and India, respectively.
Altogether, this special issue, 43(8–10), makes a significant addition to the journal’s long-stand-
ing collection of papers on research topics of electric power engineering for renewable energy.
Some of those papers are the fundamental for this book with, in total, 14 chapters. The papers
have been updated and reviewed, and each chapter has some practical examples/exercises that are
used to study more detailed technology. The examples are supported with the opportunity to do
®
®
MATLAB /Simulink and ANSYS simulations.
®