The electric power systems

The electric power systems (EPS) went through a major overhaul the last few years in terms of its operation and its organization. There has been a shift from the monopolistic EPS to the deregulated EPS where a number of new power suppliers and generating companies (GenCos) in electric power market has grown.
In the Philippines, the EPS barely keeps up with insufficient power supplies, along with infrastructure and energy inefficiencies. Blackouts and power shortages are costing the country an estimated US$20 billion annually 1.
Energy-sector stakeholders in the country have come up with a solution on how they can address the insufficient power reserves in the country especially during the summer months. To mitigate the load requirements of the grid during high electrical load demand (peak) times, the National Grid Corporation of the Philippines (NGCP) – the system operator of the main grid, encourages its directly connected customers to participate in its Interruptible Load Program (ILP) which is a demand side management scheme set by the Energy Regulatory Commission (ERC) to help ease the impact of tight supply during yellow and red alert periods. A red alert is an alert issued by the system operator when there is a generation deficiency or there is critical loading or imminent overloading of transmission line or equipment, as defined in the Philippine Grid Code 2. NGCP is in charge of operating, maintaining, and developing the Philippines’ state-owned power grid. It also controls the supply and demand of power by determining the power mix through the selection of power plants to put online (i.e., to signal power plants to produce power, as power plants will only produce power or feed their power to the transmission grid when directed by NGCP) 3.
Under the aforementioned program, NGCP’s Directly Connected Customers (DCC) may voluntarily enter into an agreement, where they may be requested to run their own back-up generators (or distributed energy sources) to partially decrease or completely cease drawing power from the main grid in times of an electricity supply shortage. This will provide all grid-connected consumers with a more stable supply of electricity. Contrariwise, participating DCCs will be compensated for their internally generated power by NGCP through a formula provided by ERC 4.
As the national economy grows, Filipinos also have increased energy usage. But sadly, there has been shortage as evidenced by the power curtailment and rotational brownouts the past years 5. Filipinos need more reliable sources of energy. Because of this, distributed energy sources (DERs) or distributed generations have gained momentum in smaller communities.
Distributed generation refers to electric power generation at or near where it will be used 6. These could come from portable diesel generators, batteries, hydropower, solar panels, wind turbines or combined heat and power. Distributed generation is also called o 7n-site generation or decentralized generation 8. It may serve a single structure or may be part of a microgrid (a smaller grid that is also tied into the larger electricity delivery system), such as at a major industrial facility or a large college campus.
The basic structure of a microgrid has distributed energy sources, storage devices and flexible loads. It can operate connected to the main grid or isolated mode (also called island mode).