The Luzon grid has been practically under yellow alert for most of the day for weeks now. The Visayas grid experiences the same deficiency in reserve.
The prevailing explanation has been due to the simultaneous plant outages. It is important to stress that an outage does not automatically result in power interruption. To use a more relatable analogy, if you’re running a laundry service, the loss of one washing machine does not mean the whole shop would close down. The loss of two or more should keep you worried.
A power plant may be allowed to be on planned outage for maintenance but it does not mean the reserve will be thin; the reserve does not necessarily have to be thin. This is because there is a schedule to be followed and planned out ahead of time when and how long power plants should be on shutdown. Therefore, we know if the schedule is followed and when generators will be on outage.
But why do generators shut down in the first place? Generators are made up of many parts which may be moving or not. These generator parts need to be maintained because the cost of having a fault is usually higher than the cost of preventive maintenance. In other words, there is an allowable time for generators to be on outage for the upkeep. Any exceedance of this allowable time is penalized because they are expected to be already synchronized to the grid to supply power.
The Department of Energy (DOE) declared early on that there would be no power crisis. It was a bold and sweeping declaration that was eventually found to be not true.
At the grid level, that means we are not talking about power interruptions at the distribution such as those caused by maintenance of lines, substations, or localized power interruptions caused by faults, we can quantify how many hours in a year there will be brownouts because of the probability of simultaneous plant outages.
The very nature of plant outage is probabilistic. This means there is a chance that plants will be on outage at the same time which will lead to insufficient generation. The question that needs to be answered is this probability, the likelihood of occurrence that many power plants will be on outage. The more plants that are on outage, the greater the chance of having power interruption. I make a distinction here that power plants, for whatever reason, are on shutdown. The Energy Regulatory Commission (ERC) can sanction generating units that will exceed the allowable shutdown. This means that the ERC can legally ask generators to pay if they are already more than the planned outages.
So, what is the solution? We need to build more power plants. If we are targeting increased renewable energy penetration, we need to study how this can affect the stability of the grid, given that we want to phase out thermal power plants providing inertia. Modifying end-user behavior, which is what the DOE is gearing toward, will take some time to take off. It will not be easy to tell consumers to lessen the use of appliances given that the heat mitigating measures heavily involve the use of cooling appliances which use up much energy (read: higher electricity bills).
The power problem of the country is a lot more complex and we cannot point to a single solution.
Edward Joseph H. Maguindayao, University of the Philippines Los Baños