IEEE Power & Energy Magazine - November/December 2014 - 58

The typical operation of a pipeline system
includes scheduling, balancing, central dispatch,
and emergency control of natural gas flows.
utilized to minimize power system operating costs by taking
into consideration power transmission constraints, natural
gas pipeline network constraints, and natural gas contracts.
The followings constraints are specific to Turkey:
✔✔ Contractual constraints: Natural gas contracts with
the exporter countries impose restrictions on the flow
of natural gas.
✔✔ Individual generator constraints: Generating units have
individual constraints, such as ramp rates for increasing
and decreasing output, minimum run times and downtimes, maximum amounts and rates of emissions, and
seasonal maximum and minimum capacity ratings.
✔✔ Power balance and reserve constraints: The seasonal
maximum and minimum capacity ratings of the naturalgas-fired generator units should be considered, particularly during summer peak loading conditions. Gas-fired
power plants, which provide fast spinning reserves,
may suffer capacity decreases due to exhaust temperature constraints. These may introduce challenges
with respect to meeting the overall power balance and
reserve constraints.
✔✔ Spinning reserve constraints of natural-gas-fired
plants: Gas-fired power plants with self-owned storage
tanks can reserve some natural gas to be used during
peak hours. The mid- and long-term technical and economic aspects of constructing natural gas storage can
also be analyzed.

Coordinated Operation of Natural Gas
and Electric Power Systems
Turkey's strategy for the secure, competitive, and sustainable
operation of its energy system is based on the development of
energy efficiency in various communities and load centers, the
implementation of competitive markets utilizing smart infrastructure, and the interdependent exploitation of thermal and
renewable energy sources. Energy efficiency could curb additional demand, reduce energy imports, and mitigate pollution. It
also provides a long-term solution to the challenges of fuel shortages and high energy prices. Despite the vital role that energy
efficiency plays in reducing peak demand, only small segments
of its vast economic potential are currently being exploited in
Turkey. Competitive energy markets minimize hourly electricity prices, reduce the need for electric infrastructure expansion,
and optimize long-term price signals for investment. The coordinated exploitation of thermal and renewable energy resources
would reduce CO2 emissions, minimize infrastructure operating
costs, and curb the country's dependence on fuel imports.
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ieee power & energy magazine

The natural gas produced from wells goes to natural
gas processing plants or directly to the natural gas pipeline
network, depending on the original quality of the wellhead
product. Natural gas market hubs are locations where pipelines intersect and natural gas flows are transferred. Two
key services offered by hubs are interconnections of pipelines and the physical receipt and delivery of gas so as to
meet short-term balancing needs. Such services commonly
include wheeling, storage, and peaking. Most of the pipeline capacities with highest priority are sold to local distribution companies (LDCs) in accordance with expensive firm
contracts. LDCs can resell those capacities not utilized in
the market each day. BOTAS¸ is the state-owned company
in Turkey that dominates or is responsible for much of the
natural gas trade (see Figure 8). Recent natural gas market
regulations in Turkey, however, serve to promote the progressive development of a competitive natural gas market similar
to the electricity market. The discussion that follows may be
more applicable to countries with more mature natural gas
markets but over time will be increasingly relevant to the
energy market in Turkey.
Transactions in a market-based natural gas industry
must simultaneously clear natural gas and transportation
components at minimum total cost. Market participants
in the natural gas industry match the available supply of
natural gas and transportation contracts with their demand
through decentralized bilateral transactions. Each market
participant minimizes its own costs of natural gas and
transportation. But the total costs of natural gas to end
users may not be minimized if an inefficient transportation system does not minimize the suboptimal operation
of pipelines.
The typical operation of a pipeline system includes
scheduling, balancing, central dispatch, and emergency control of natural gas flows. The natural gas supply and transportation services have to be coordinated by scheduling and
balancing. Using the shippers' pipeline capacity demand
and information about the volumes of natural gas, a pipeline
company carries out scheduling and balancing activities and
then determines the natural gas flow in the pipeline, which
can minimize transportation costs while satisfying shippers'
demands. Central dispatch and emergency control maintain
system balance and guide natural gas flows through the pipeline system in real time. The natural gas transportation procedure is shown in Figure 23. In some circumstances, liquid
natural gas and underground natural gas storage can also
satisfy natural gas demand.
november/december 2014

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2014