Solar overcapacity could trigger Visayas blackouts

by Myrna Velasco March 28, 2016

http://www.mb.com.ph/solar-overcapacity-could-trigger-visayas-blackouts/

The Department of Energy (DOE) is giving more attention to Mindanao on power supply during election period, but at this stage, stakeholders in Visayas are cautioning that blackouts may actually happen in their grid during that critical time.

Data culled from the National Grid Corporation of the Philippines (NGCP) showed that frequency excursion in the power system already caused ‘stress’ and power interruptions in the grid in several instances, mainly due to sudden swing in the generation of solar plants in Negros.

It is a given fact that there had been over-development of solar capacity in Negros Occidental, and this is seen triggering blackouts in the grid if the system’s need for ancillary services – primarily for frequency regulation – could not be addressed with some sense of urgency.

“Everybody is worried about power supply in Mindanao…but the real problem of blackouts occurring during the election period may likely be in Visayas,” a power plant firm in Visayas has noted.

System operator data had further manifested that solar generation logged swings of 20-percent and 50-percent in some instances, and this triggered power interruptions due to system upsets.

With the addition of more solar plants this March, this is seen to be a worsening scenario for the grid.

The energy department previously indicated that it sees “good scenarios” for both Luzon and Visayas grids during the election period and the rest of summer months – but that is only when it comes to power supply.

Nevertheless, the DOE might have been missing out on assessments in the overall functioning of the electricity system – that the ‘real picture’ is actually dismal.

There have been several solutions being proposed for the grid’s dilemma, but the government and NGCP have yet to firm up plans for such.

When asked during a stakeholder briefing on battery storage at the American Chamber of Commerce of the Philippines (AmCham) forum, AES Philippines managing director Neeraj Bhat opined that it is a problem that stakeholders are still trying to sort out in the grid, especially with the anticipated solar capacity additions this month.

The American firm is currently working on a 40-megawatt battery storage system project in Kabankalan, Negros Occidental which could be one of the options to sort out the grid’s dilemma – but it will be up to NGCP and the government to decide on the technology choices or preferences.

“As many already know, there have been no frequency regulation providers in the Visayas right now.

There’s 700 megawatts in Luzon – these are hydros, but there are no hydro plants in the Visayas and NGCP has contracted for zero for frequency regulation, because in large part the assets which would have been able to provide that which are the hydro plants, are not there,” Bhat said.

He opined that being in that situation, “it’s a big risk for the system,” while adding that the other big issue in Negros is the transmission constraint between the islands.”

Bhat emphasized that if all the solar plants will be operating at optimum load on a bright sunny day and if the coal and geothermal plants will also be injecting capacity, even at minimum load, “you still have a number that’s higher than what the transmission link in Negros and Cebu can take.”