Old power station turbines can be repurposed as inertia services via a stability market. Example in the UK: https://www.neso.energy/news/deeside-power-station-begins-wo...

Batteries are sweeping stability markets wherever they are set up. They're simply cheaper and better at it.

	▲	jonatron 12 hours ago \| parent [-]
		I'm not sure this is true in the UK at least, which may be because the grid operator is conservative / cautious https://www.energy-storage.news/uk-grid-forming-batteries-mi...