IEEE Power & Energy Magazine - May/June 2017 - 38

To allow R&D results to become business as usual,
utilities need regulatory changes, but even more importantly
they need stable and predictable regulatory frameworks.
implementation of new SG projects, including software maintenance costs for projects in operation.
DRES Should Have Incentives to
Take Part in Network Operation

DRESs sometimes present an intermittent production profile
and thus are treated differently from conventional generation
units. These differences should be reduced progressively. Some
DRESs can offer flexibility through the provision of reactive
power or by combining storage with generation, but the development of these capabilities needs to be incentivized. Customers
deciding to produce energy should accept that their equipment
is part of the grid and should assume an active role in the system.
DRESs can be designed to provide certain services to the
grid, including communications interface and control of reactive power injection or consumption. The final responsibility for
securing network operations will remain in the DSO's hands,
and the same level of reliability must be maintained after any
DRES SG integration.
Roles and Interactions with New Actors
Should Be Clearly Established

DRESs, new devices [i.e., energy storage systems (ESSs)], and
SGs in general will require new forms of collaboration among
all participants, including consumers, retailers, and DSOs.
Regulations should enable those interrelations. For example,
aggregators might act as intermediaries between DSOs and consumers to manage consumption, following the necessities of the
grid. However, the DSO is responsible for ensuring the adequate
operation of the network, and, although it is not directly controlling the loads, it is liable for problems that might arise due to the
aggregator's difficulties to meet its commitments.
We can find a similar case related to ESSs. In the spirit of
opening the electricity market, the European Commission is
proposing a new market model in which third parties provide
flexibility services to grid operators. In this context, DSOs
would not be, in principle, allowed to own ESSs. Who will
be responsible in case of ESS failure or if the service provider
doesn't have enough capacity to meet its commitments? There
are solutions for every issue, but the responsibilities of every
stakeholder must be clear and suitable mechanisms to guarantee the security of supply must be established.

Other Factors
Regulation is not the only hindrance to the implementing SG
solutions. To make them business as usual, there is work to
do on standards, operational procedures, and costs.
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Lack of Standard SG Components

There are many standards for SG performance, often customized for each solution, and there exists a large and increasing
base of already deployed DRESs. It will require a huge effort
for the DSOs to manage a power system with a wide variety of old and new devices with different characteristics and
interfaces. Advances in the standardization of components,
consensus among DSOs requesting similar functions, and
interoperability between products will facilitate integrating
various SG technologies.
New Distribution Network Processes,
Experience, and Formation

Active distribution networks, reverse power flows, and massive DRESs affect network operation processes and require
redesigning current working procedures. Traditional practices
may no longer be effective.
Higher distribution grid observability is needed, and new
equipment, software systems, and advanced applications have
to be integrated into existing elements. Side effects from new
systems and devices can appear.
As technological complexity increases, the skills and
expertise of personnel needed to operate the new distribution
network will be different. Specialized training for personnel
is essential for integrating SG technologies. The successful implementation of an automatic grid recovery system at
Iberdrola was founded on a special training for dispatchers,
which gave them the capacity to disable the system to recover
control if necessary. When people with the necessary skills
and training test the new systems to verify their efficacy, the
transition is smoother.
Cost, Complexity, Scalability, and Replicability

In general, centralized solutions are more expensive and
more effective than stand-alone ones that work independent
from the rest of the grid to solve DRES-related issues. Utilities usually prefer centralized solutions to maintain the control and observability of the systems, but decisions about the
most complex and expensive systems are not easily made.
The potential of the solution should be clear and the validity
of the approach for other regions and larger scales should not
offer any doubts about the validity of the solutions we are
trying to apply.
Side effects are not always evident. For example, it has been
confirmed that SG solutions sometimes produce an increase
of grid losses (around 1% in our experiments). In the cases
analyzed, a few SG solutions reduced losses (STATCOM with
may/june 2017

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - May/June 2017