The Canada Pension Plan Investment Board (CPP Investments) will spend £300 million to take its stake from 6 per cent to 11 per cent.

British-Californian firm Generation Investment Management, whose chairman is climate campaigner and former US vice-president Al Gore, will inject £45 million, keeping its interest at about 10 per cent.

The fourth shareholder, Tokyo Gas, has a 10 per cent stake and is expected to take up an option to subscribe for additional shares that will maintain its percentage interest.

In a statement, Octopus said the funding round would be used to “accelerate international growth and expansion of low-carbon technologies, especially heat pumps”. It was “expected to create 3000 green jobs in the UK alone in 2024.”

This suggests a significant chunk of the capital will be deployed on a new venture announced in September: a custom-built heat pump, with its own smart meter and tariff, which Octopus is looking to install in the homes of many of its 11 million-plus British customers.

The heat pump was designed in-house, and is set at a price point that aims to take best advantage of an increased government grant for households to install them. Octopus CEO Greg Jackson said in the statement that the company now needed to “drive real scale” in this business.

Octopus recently acquired two competitors in Britain which, together with organic growth, has taken its market share to 21.3 per cent, overtaking the former market leader British Gas with 20.4 per cent.

But Origin’s deeper interest lies in the company’s Kraken technology platform, which can be licensed to other energy providers, and is also now being offered to other utilities such as battery storage, water and broadband suppliers.

According to Octopus, the number of contracted accounts using Kraken worldwide has jumped in the past two years from 17 million to 52 million, across 10 countries. It is targeting 100 million customers on Kraken by 2027.

Mr Jackson has said Kraken could turn Octopus into the Amazon or Uber of energy – that is, a dominant platform used by most other retailers or operators.

Mr Calabria said Octopus’s “business, strategy, proprietary technology platform and team” would provide “an important avenue for future growth” at Origin. Origin first bought its 20 per cent stake in Octopus in May 2020, and has licensed Kraken for its own retail operations.

Octopus Energy also has an electric vehicle leasing business, and an investment portfolio of renewable generation assets worth £6 billion.