The paper looks at the issues of operation safety of the national power grid and the characteristics

of the national power grid in the areas of transmission and distribution. The issues of

operation safety of the national transmission and distribution grid were discussed as well as threats

to operation safety and security of the electricity supply related to these grids. Failures in the

transmission and distribution grid in 2017, caused by extreme weather conditions such as: a violent

storm at the night of 11/12.08.2017, hurricane Ksawery on 5–8.10.2017, and hurricane Grzegorz on

29–30.10.2017, the effects of which affected tens of thousands of electricity consumers and led to

significant interruptions in the supply of electricity were presented. At present, the national power

(transmission and distribution) grid does not pose a threat to the operation safety and security of

the electricity supply, and is adapted to the current typical conditions of electricity demand and the

performance of tasks during a normal state of affairs, but locally may pose threats, especially in

extreme weather conditions. A potentially high threat to the operation safety of the national power

grid is closely linked to: age, technical condition and the degree of depletion of the transmission and

distribution grids, and their high failure rate due to weather anomalies. Therefore, it is necessary

to develop and modernize the 400 and 220 kV transmission grids, cross-border interconnections,

and the 110 kV distribution grid (especially in the area of large urban agglomerations), and the MV

distribution grid (especially in rural areas). The challenges faced by the transmission and distribution

grid operators within the scope of investment and operating activities, with a view to avoiding

or at least reducing the scale of grid failures in the case of future sudden high-intensity atmospheric

phenomena, are presented.