Chapter 1
Introduction
1.1 Background
Electricity is one of the necessities in the ordinary business of life, and a major
driving force for Thailand’s economic growth and development. The unstorable
nature of electricity means that the supply of electricity must be always available to
satisfy the growing demand. Since the commission of power plants and the
transmission may take between five to seven years, and Thailand‘s power purchase
from a foreign source is limited, it is imperative that the power development plan
must be well conceived. Inevitably, a reliable medium and long run load forecasts are
prerequisites for a well conceived power development plan.
An under forecasted load leads to an under expanded power system which
leads to a brown out or a black out power system. On the other hand, an over
forecasted load leads to an over expanded power system. In this case, the unnecessary
costs are passed on to the power consumers through a higher power tariff.
There are several factors that affect electricity demand. The key factors are
electricity price, number of electricity appliances, income, temperature, and consumer
load pattern which differ by regions and consumer groups. A reliable load forecast
methodology must “correctly” gauge the effects of the key factors on electricity
demand.
The load forecast working group has a mandate to oversee the long term load
forecast for the whole country. In the past, the load forecast working group has
focused only on the forecasts which affect the demand for the EGAT system. The
forecast did not include the direct demand for powers from the SPPs and the IPPs
which are permitted to sell their power to nearby customers. The load forecasts
submitted to the load forecast working group were under the responsibility of the
three power authorities. The MEA is responsible for the load forecast for the
Bangkok, Samut Prakarn, and Nonthaburi. The PEA is responsible for the load
forecast for the remaining provinces, and the EGAT is responsible for the load
forecast of its direct customers.
Recently, a seminar on “The load forecast” was organized by the three power
authorities to allow the officials responsible for load forecasts to exchange their
opinions on the “appropriate” methods for organizing and conducting the load
forecast. At the conclusion of the seminar, the participants agree that a forecasting
center for the collection of relevant data and for the revision of forecasting
methodology should be established. This center should replace the three power
authorities in conducting the load forecast and disseminate the knowledge to the
public.
1.2 Objectives of the Study
1.2.1 To revise and update the load forecasting methods that are reliable and
can be conveniently audited
1.2.2 To conduct the medium and long term load forecast for the country
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1.2.3 To prepare the necessary ground works in equipments and personnel for
the establishment of the load forecasting center.
1.3 Project Framework
1.3.1 The revision of the forecasting methodologies and the design of the
forecasting models will focus on
1) The review of load forecasting methodologies, their reliability and
short comings in several countries
2) Determine factors affecting the demand for electricity such as
economic growth, temperature, power tariff, energy conservation policy
3) Design the load forecasting models by customer groups
4) Provide the load forecast by the following categories
Electricity energy demand
 MEA and PEA
– residential
– small general service
– medium general service
– large general service
– specific general service
– government and non profit organization
– agricultural pumping
– temporary and free electricity
 EGAT
– Direct customers
Electrical power demand
 MEA
 PEA
 EGAT
In order to facilitate the power development plans of EGAT and PEA,
the load forecast will be disaggregated into 4 regions as defined by the two power
authorities.
5) In collaboration with the load forecast working group, a seminar on
the results of the load forecast will be organized for the selected groups from the
public and private sectors to create better understanding and acceptance of the
forecasting method
1.3.2 In order to prepare the necessary foundations for the load forecasting
center it is proposed that
1) A data base is designed to cover the following areas
– electricity energy demand, peak demand, and the number of
electricity customers as stipulated in 3.1.4
– other data deemed essentials to load forecasting such as power
customers’ load profile, economic growth by sectors, population growth, temperature,
power tariff, and government energy policy.
The data base will be set up under the jurisdiction of the Energy
Planning and Policy Office(EPPO) with links to the three power authorities’ servers.
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2) Organize training sessions to prepare the assigned personnel for the
responsibility of data collection, analysis of factors affecting the electricity demand,
and in the actual forecasting
1.4 Study Sequence
1.4.1 Review the reliability and short comings of the forecasting methodology
in several countries.
1.4.2 Analyze factors affecting electricity demand and prepare the load forecast
in collaboration with the load forecast working group
1.4.3 Design the data base for load forecast
1.4.4 Organize a seminar for selected groups and review the results for the load
forecast adjustments
1.4.5 Submit the final report on the load forecasting to the load forecast
working group for approval