Grid Supply Point Archetypes

The grid was built to flow top-down. A countryside revolution is trifurcating demand from the perspective of grid operators

When the National Grid was originally built, it had a few centralised big power stations, and the flow of power was one way from there, using large, high voltage transmission cables until it made the one way transformation down to a succession of lower voltages on the distribution grid, and eventually into homes and businesses.

The border between the transmission and distribution grid was the grid supply point. These remain a crucial measuring point for Elexon (who manage the settlement of the grid), and provide a consistent snapshot to compare the changes to the shape of the demand around different archetypal areas of the country. Each Grid Supply Point serves a densely populated urban area, or a more sprawling rural one.

What the operator sees

Few things to bear in mind. The National Grid can't directly see most solar installations, or smaller wind farms. Traditionally, they just see the net demand, minus that which has been “disappeared” by the solar that hits the transmission grid; though the distribution networks increasingly have visibility further down that can be shared upward too.

The old world: everywhere looked much the same

In the old world, demand had a predictable shape. A larger evening peak, a smaller morning one. In areas with more business and industry a midday one as well. All in all however, nothing that dissimilar across the country. And they'd move roughly in line with each other as we moved through the seasons.

A revolution that started in the countryside

Most profound technological and social changes start in cities. Solar is an exception; as urban areas lack free space and rooftop availability (flats, terraced houses etc). As a result, the summer demand shape for rural area GSPs is one where for a growing share of the year, they run in reverse in the midday sun.