IEEE Power & Energy Magazine - November/December 2020 - 18

Large Amounts of Distributed Energy
Resources." It describes a new concept
for the control and operation of grids with
high levels of DERs of all types. The autonomous energy grid concept realizes a
cellular structure for the grid, with multilayer distributed control implemented
to enable highly flexible, resilient, and
reliable operation of the grid cells in an
optimal manner. Required control coordi-

nation between the grid cells is structured
to reduce communications requirements
while still seeking to realize optimal operation of the entire power system. The
scalability of the proposed concept is discussed in detail, and examples of largescale, lab-based, and real-world implementations are presented.
Kazuhiko Ogimoto and Hiroshi Wani
from the University of Tokyo and Ky-

ushu Electric Power Company, respectively, offer "Making Renewables Work:
Operational Practices and Future Challenges for Renewable Energy as a Major
Power Source in Japan," which provides
a detailed view of grid operation challenges related to the high levels of DERs
in the form of distributed PVs and wind.
The article focuses specifically on the island of Kyushu, which has experienced
significantly higher levels of renewable
penetration compared to load than much
of the rest of Japan. A detailed view of
operating practices, both new and old, is
provided, along with an account of how
those practices, combined with large forecasting errors, led to an emergency operating condition in March 2019. Lessons
learned from this event are expertly presented, and new operating methods, now
employed, are described in detail. Furthermore, a view of future improvements in
power system operation with high levels
of renewables is given via a discussion of
grid constraints and the potential for additional flexibility from virtual power
plants and managed EV charging.
Continuing the theme of islands with
high levels of distributed PVs, the fourth
article, "Back in the Race: Achieving
100% Renewable Energy in the Canary
Islands," by Ricardo Guerrero Lemus
from the Universidad de La Laguna,
Spain, describes the challenges of reaching a 100% renewable energy target by
2040. The article starts with a comprehensive overview of the current state
of many types of renewable generation
across the Canary Islands. Specific operational challenges are highlighted, such as
a highly seasonal, tourist-driven load profile and relatively deep channels between
islands, which make the interconnection
of island systems difficult. Additionally,
the article provides a more detailed discussion of the operational challenges and
the amazingly high renewable operating
levels realized on both the El Hierro and
Tenerife islands. The integration of a major pumped-storage hydropower system
on El Hierro and the lack of any significant amount of storage on Tenerife provides a good comparison of how system
operation requirements can differ, even
within the same region.
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IEEE Power & Energy Magazine - November/December 2020

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2020
