National Grid says there soon will be times in the year when the market could meet the total demand for electricity through renewable generation only and these periods will increase as more and more renewables are connected and more load actively participates in the market.

“This is very different to the traditional model of power system operation and, to enable all of this low-carbon generation operate unconstrained, requires us to address and solve some critical engineering challenges,” it says.

“Our ambition is that, by 2025, we will have transformed the operation of the electricity system such that we can operate it safely and securely at zero carbon whenever there is sufficient renewable generation on-line and available to meet the total national load.

“Zero carbon operation of the electricity system by 2025 means a fundamental change to how our system was designed to operate – integrating newer technologies right across the system – from large-scale off-shore wind to domestic scale solar panels to increased demand side participation, using new smart digital systems to manage and control the system in real-time.”

The document identifies the areas where traditional generation has delivered services such as inertia, frequency control and voltage, which will now have to come from wind and solar, plus various storage technologies and other “demand side” options.

This will require a re-design of the markets to better represent the new technologies and the passing of the old ones. It has now set a work plan that sets various deadlines in coming years, and tenders for providers of new technologies.