Page 274 - Fluid Power Engineering

Deploying W i nd T urbines in Grid 241

estimates for interconnection. It includes a power flow and
short-circuit analysis. In the United States, a deposit of $10,000
is required to initiate the study, which is performed by the
RTO or its consultants. It must be completed in 45 days after
a completed application has been received; RTO may seek an
extension by providing a reason to the customer.
System impact study: This is a detailed transmission planning

study to understand the impact of the proposed wind farm on
existing transmission, generation, and customers. The analy-
sis performed includes, impact on short-circuit power, dy-
namic and stability issues, protection systems, safety and
reliability of transmission, and any other adverse impacts on
the system. The deliverable is a written report on improve-
ments to the transmission system, and estimated cost. In the
United States, a deposit of $50,000 is required; the study is
performed by the RTO. This study must be completed in
90 days; however, if a cluster or group study is performed,
then an additional 90 days is available.
Facilitystudy:Thisisadetailedengineeringstudytodesignthe

interconnection substation and transmission and to provide
estimates for the cost and time to implement the upgrades.
In addition, it delineates the responsibilities of the wind farm
developer and the local transmission company to upgrade
transmission. In the United States, the study is normally per-
formed by the local utility for the RTO; it requires a deposit
of $100,000. This study should be completed in 90 or 180 days
depending on accuracy of cost estimates requested, ±20 or
±10%, respectively.

In all three studies, a refund is issued or additional charges are
billed based on the actual cost of the study. An interconnection re-
quest is inserted into a queue and time to process the request varies
from region to region. The timeframes specified above are based on
FERC guidelines. Prerequisite to an interconnection application are
access to land either through ownership or lease agreements. The in-
terconnection will require a developer to choose between two types of
services: Energy resource interconnection service (ERIS) and network
resource interconnection service (NRIS). An ERIS has a much lower
bar because it does not require any transmission system upgrades. It
allows a generation to interconnect in order to deliver output using
existing firm or nonfirm transmission capacity on an “as available”
basis. NRIS requires a complete network analysis, while treating the
proposed wind farm as a network resource comparable to any other
large generation facility. In this analysis, the system is analyzed at
peak load and under a variety of stressed conditions to ensure that
the proposed generation facility operating at full capacity along with