Why did the electric grid of Israel collapse?

Why did the electric grid of Israel (partially) collapse on Friday, June 2nd? A lot of rumors and accusations run in the media, though the immediate cause is of course the extreme heatwave, affecting the country with temperatures above 40C. The more profound causes are a matter of discussion and controversy, considering that the 12.5GW demand wasn't actually that high (mostly because it was weekend) and Israel had successfully met a much higher demand in the past exceeding 14GW. Was it the mismanagement of the grid by the grid operation company Noga? Or the fault of the Israel Electric Corporation (IEC), which is still a de-facto monopoly in electricity generation, transmission and distribution? Or were the renewables to blame since much of the grid reserve collapse occured during afternoon and evening, as the solar production phased out? Or maybe something else?

The truth is complicated. Certainly, the electricity market isn't planned for peak demand in early June, rather expecting the surge in the regular peak demand season during July-September. The exceptional heat wave met the Noga grid operation company and the IEC unprepared and non-coordinated to power up reserve units of the IEC days or hours in advance. The gross generation deficit was on the order of 700MW - not something the IEC couldn't deal with. Just for the reference, the then paused coal units of the IEC could provide 900MW. The net generation deficit (without reserve) was even smaller - just 103MW.

Figure 1. Electricity generation segment trends in Israel by primary energy source as of December 2022. Notes: diesel is calculated combined with methanol; natural gas is including both CNG and LNG.

The medium-term reasons for electricity shortage include the temporary pause of the 428MW Reding gas power plant in Tel Aviv (due to technical reasons), the prolonged malfunction at the 300MW Maale Gilboa pump accumulation plant, the Rotenberg coal power plant unavailability due to a maritime disaster earlier this year and the multi-month delay in deployment of two IEC gas generation units. The more immediate technical cause for the electricity supply shortage was an unexpected malfunction of the Karish gas project, which created acute gas shortage among several of its customers including gas generation power units and hence reduced generation.

And finally there is a question - what was the part of renewables in this problem? The solar generation was indeed lower on Friday due to cloudy and dusty weather, reducing cumulative solar power by more than a quarter during the afternoon. This is however only marginally responsible for the shortages, which were most evident during late afternoon and early evening. The solar generation isn't expected to contribute during those hours anyway since backup conventional generation or electricity storage need to fill the gap. Indeed, the largest storage project in Maaleh Gilboa was offline on Friday, and hence when the solar generation expectedly reduced, there was no required backup. The Electricity Authority may also be questioned for its vague policy on decentralized storage deployment as solar backup, which is extremely slow.

The extended annual report on the Israeli electricity market can be purchased at LNRG Technology digital store.