Poland, UK carry most summer power supply risk – ENTSO-E

The Polish power system has been identified as the most exposed to supply shortages in the event of severe weather conditions this summer in Europe, according to an outlook published by European system operator’s association ENTSO-E on Tuesday.

The UK power system could also find itself stretched in the latter part of September, the report said, should colder temperatures arrive early and coincide with low wind power. This would force the market to rely on its maximum import capacity to avoid shortages.

In Poland, potential risk has been identified in several weeks between June and August, during which a heat-wave could limit power plant availability and push demand beyond import capacity.

Such a situation would be a repeat of last summer’s conditions when day-ahead prices spiked to zloty (Zl) 484.40/MWh (€110.44/MWh) on 10 August and a European safety standard in transmission system operation was breached just over a month later on 15 September.

The risk to the Polish system is associated with unscheduled flows, known as loop- or transit flows, which cause congestion and limit commercial flows on the border with Germany. Unscheduled flows are due to market transactions concluded outside of Poland, usually between parties operating within the German bidding zone.

Interim measures have so far been “insufficient” for summer 2016, the report stated. A sustainable resolution in terms of a flow-based capacity calculation method and a reconfiguration of the bidding zones, or at least control blocks, will not be implemented before 2018, it said.

Supply may also be constrained to the UK in the second half of September, notably in week 38, the report said. Extreme conditions were in this case related to low wind and temperatures, although the probability of insufficient import capacity was deemed as very low.

The report also identified the oversupply risk of generation outstripping export capacity in the case of Germany and Belgium. German excess capacity is likely to occur during peak hours as a result of high solar generation, while Belgium might lack the flexibility to limit production during some weeks in July and August due to full nuclear availability.

Combined net generation across Europe has declined from last summer, as traditional generation plants, including dispatchable units, are being decommissioned at a faster rate than new renewable sources are being installed, the report also said. joachim.moxon@icis.com