There was an article about the current debt of National Grid

National Grid’s near-£50bn debt pile set to push up energy bills

One can see the figures from the National Grid’s financial reports:-

National Grid Q2 6K 2026/27

Courtesy of National Grid PLC

We can see the current debt is a total of £48.599 Billion

We can see below the interest (financing costs) of the debt:-

Courtesy of National Grid PLC

Interests costs are at £1030 million. (£1.03 Billion)

So on [£1.03 Billion /£48.599 Billion] gives a rough interest rate of 2.1211% which is a very low interest rate on a total debt of £48.599 billion