Since the tight supply and demand in the winter of 2020, there has been active debate that a pool system should be introduced into the electricity supply and demand system. The tight supply and demand may continue in the medium to long term, so it is said that the Ministry of Economy, Trade and Industry is aiming to revise the Electricity Business Law to realize the pool system in the ordinary Diet session in 2023.
The pool system mainly refers to the power supply and demand / trading system introduced by ISO (Independent System Operator) and RTO (Regional System Operator) such as PJM in the United States.
Although there is no strict definition, the pool system is a system that realizes optimal economic efficiency and stable system operation based on the following two principles.
1 All wholesale power is obliged to trade through the exchange operated by the grid operator.
2 The grid operator has strong authority over the management and operation of the grid and supply and demand.
The most important is that the grid operator becomes the operator of the exchange. As a result, the grid operator manages the limit prices of all power supplies, and as a result, not only realizes the merit order, but also determines the priority of output adjustment (so-called congestion management) when grid constraints occur.
In addition, the grid operator has the authority to approve and deny the stop schedule associated with the construction plan of the transmission and transformation equipment, and in addition, maintain the reliability of the grid by managing the schedule such as periodic inspections of the power plant and issuing power supply commands. It will be possible to do.
What kind of change will happen in Japan if the pool system is introduced?
First of all, it is thought that the operators of wholesale electricity transactions will be unified into OCCTO (Organization for Cross-regional Coordination of Transmission Operators). Currently, electricity trading is roughly divided into three categories: capacity market operated by OCCTO, supply and distribution adjustment market by transmission and distribution grid council, and wholesale electricity trading market by JEPX (Japan Electric Power Exchange). It is expected that the operation will be unified with OCCTO.
In addition, it is conceivable that the authority for planning and management of core / local system construction and power supply orders, etc., which the former general power transmission and distribution operators in each region are currently in charge of, will be transferred to OCCTO to a considerable extent, and the decision-making of the electric power company will be be gradually lost.
In reality, there are many adjustments to the transfer of authority between OCCTO and the Transmission and Distribution Grid Council, the former general transmission and distribution operator, and JEPX, and there are various possible aspects of the power supply and demand system after the system revision. However, in addition to the fact that the Ministry of Economy, Trade and Industry attaches great importance to ensuring a stable supply, some electric power companies also tend to prefer a pool system. It is inevitable that the OCCTO’s authority as an ISO will increase in the future as the power supply and demand system shifts to a pool system.