The Energy Department may limit the exposure of renewable energy sources in areas where there are transmission line constraints, an official said over the weekend.
Energy assistant director Mario Marasigan told reporters at the sidelines of the recently-concluded Solar Summit the department was trying to avoid duplicating the situation in Negros island where there was too much solar concentration in one area.
“What we are looking at is we will set a certain percentage on a per grid segment, then we will limit what the line can accommodate,” Marasigan said.
He said the department would coordinate closely with grid operator National Grid Corp. of the Philippines to ensure a yearly transmission update, especially with the entry of variable renewable energy, such as wind and solar power projects.
“We are coming up with a policy. Part of the policy is, we will look at where demand for solar is, it should be the daytime demand. For wind, it should be in accordance with its generation profile. Second… is the capacity of the line to accept, transmit generated power per location,” Marasigan said.
The installed capacity of renewable energy plants in Negros has already exceeded the island’s demand, resulting in the automatic reduction of generation output from solar plants to prevent the Negros-Cebu submarine cable from overloading.
Negros island has a total demand of 309 MW but available supply reached 490 MW, or an excess of 180 MW which needed to be exported to Panay or Cebu.
The solar plants include the 45-MW Sacasol plant, 32-MW Islasol I, 48-MW Islasol II, 132.5-MW Cadiz and the 58.9 MW-Sacasun.
The department noted an additional 590 MW of potential capacity of awarded solar power projects in Negros Occidental that will have to be dispatched to the grid once completed.
“We don’t have the right to stop any investment in the country but we will set a regulation that will limit another Negros situation,” Marasigan said.
National Grid is pursuing three projects that will hopefully put an end to the transmission line constraints in Negros island due to the entry of more than 316 megawatts of solar capacity.
National Grid spokesman Cynthia Perez-Albanza earlier said the grid improvement timeline could not cope with the fast construction of the solar plants, “causing constraints of existing transmission facilities.”
She said the intermittency of solar plants resulted in voltages and frequency fluctuations in Negros, prompting the grid operator to invest in additional transmission facilities.