WARSAW - Polish power grid operator PSE asked some companies to lower power use on Friday evening, while generators will need to provide extra capacity to boost reserves for the peak demand hours.
PSE announced the 'danger period' during which there would be a lack of sufficient reserves in the system would run from 1700-1900 GMT.
While the announcement of the danger period marks a precedent, the grid manager regularly pays fees to power plants to keep generators on standby and to industrial users to be ready to cut their consumption.
PSE said the announcement would not affect regular energy consumers and was not immediately available for further comment, Poland's climate ministry said it was monitoring the situation.
The reserve margin in the system was set to fall below 1000 megawatts (MW) while demand will top 22,000 MW during peak demand hours on Friday evening, PSE data showed.
When the margin falls below a critical level the grid manager is obliged to announce the danger period and call on capacity market participants to provide their services.
At noon on Friday, some 20% of Polish power consumption came from photovoltaic solar farms.
With scarce wind output and coal fired plants typically cutting production on weekends, the reserve margin would be slim in the evening, a local power trader said.
Utilities have been running their coal-fired power plants well below full capacity in recent weeks citing market conditions. Meanwhile, Poland has to import several million tonnes of coal and is struggling to fill the supply gap after banning Russian imports earlier this year.
On Tuesday, top utility PGE said in a presentation that its production units are struggling to maintain sufficient coal stockpiles and are cutting production in order to keep running.
(Reporting by Karol Badohal, Pawel Florkiewicz and Alan Charlish, writing by Marek Strzelecki; editing by Jason Neely)