National Grid ESO - Battersea power station

Is it easier to deal with too much or too little demand?

They are both scenarios in which we have to balance the system and we have tools for both.

However there is one additional challenge that we need to overcome in low demand scenarios that we don’t have with high demand.

We need something called “inertia” to manage our system. It’s a physics thing, but you can think of it like car suspension that absorbs shocks to the system.

Coal and gas generators are currently the only forms of controllable inertia generators on the system. So even when there is low demand we might have to bring on some gas and coal generators to ensure that we have enough inertia.

Also, it’s worth noting demand itself provides inertia to the system and so when demand is lower, this inertia issue is compounded.

Peaks, troughs and fluctuations in demand are something we’re used to dealing with and one of the many situations we plan for to keep the system operating smoothly.

We will continue to draw on that experience, and work in partnership with colleagues across the industry, to manage any more changes over the coming months.