The economy is largely built on a reliable supply of cheap electricity. A challenge is to keep the supply system stable and affordable with the rapid expansion of intermittent renewable energy sources.

Source: https://www.smartpowergeneration.com/the-book-power-supply-challenges/1-how-to-secure-the-electricity-supply-in-a-changing-world

The green energy transition increases the risk of power failures, if not accompanied by a grid technology transition. Traditional large coal and gas power plants, with the high inertia of their heavy rotating generators, secure network stability. They ensure a minimal deviation from the desired 50 Hz output frequency even under a relatively large, temporary imbalance between mechanical power supplied and electrical power demanded. Smaller generators, such as windmills, are less stable and may need to be disconnected from the grid promptly after occurrence of a fault, as they may possibly affect system stability, which in turn might result in a cascading outage effect, ultimately leading to a blackout.

Source: https://www.tudelft.nl/en/2018/ewi/protection-of-future-power-systems/