how electricity grids work, what a grid connection actually involves, why ai infrastructure is a structural challenge, and what renewable energy claims actually mean.
Before we can talk about what data centres do to electricity grids, we need to understand what a grid actually is. The electricity system in the UK, and most developed countries, is a network of generators, transmission lines, substations, and local distribution networks designed to balance supply and demand in real time. Every second, the grid must produce exactly as much electricity as is being consumed.
The high-voltage transmission network, run in the UK by National Grid, carries electricity from large power stations across long distances. Local distribution networks, run by Distribution Network Operators (DNOs), carry electricity from substations to homes and businesses at lower voltages. When a data centre connects to the grid, it connects at the distribution level: it negotiates with a DNO for a connection, which involves a physical upgrade to local infrastructure.
The grid was built for a world where large generators pushed power out to many small consumers. Renewables and large industrial loads like data centres are reshaping that model. Wind and solar generate intermittently. Data centres consume continuously. Managing that mismatch is one of the central infrastructure challenges of the next decade.
A data centre wanting to connect to the UK grid at 100 MW scale is not a straightforward process. It involves a formal application to the DNO, a capacity assessment, a design for the required network reinforcement, an agreement on costs, and then the physical construction of that reinforcement. In practice, this process takes five to seven years in many parts of the UK.
The queue for grid connections in the UK had grown to over 700 GW of requested capacity by 2024, vastly more than the entire existing installed generation capacity of the country. Many of these connections will never materialise. But the queue creates a real constraint on where and how fast new data centres can be built.
This is why proximity to existing high-voltage infrastructure is often the deciding factor in data centre siting, before land cost, before planning likelihood, before community impact. If there is no grid capacity, there is no facility. The engineering constraint comes first.
this is a condensed version of the lesson. the full version, with sources and figures, is being rewritten in this format. if you'd like an early read, the feedback form is open.