This week the West Midlands Combined Authority presents its case for new funding to Chancellor of the Exchequer Rishi Sunak ahead of his autumn budget. And the word 'gigafactory' is all over it.

The document, prepared by regional mayor Andy Street and by local council leaders, is a response to the 2020 Comprehensive Spending Review. Rishi Sunak asked for suggestions that would strengthen the UK’s economic recovery from COVID-19 by prioritising jobs and skills and levelling up economic opportunity across all nations and regions.

The review will set UK Government departments’ resource budgets for the years 2021/22 to 2023/24 and capital budgets for the years 2021/22 until 2024/25.

Whilst the authors refer to the HS2 Interchange at Arden Cross, to the prospect of HS2 development in Curzon Street and Digtbeth, and to investment in the Birmingham Health Innovation Campus, the word 'gigafactory' is made to do a lot of the heavy rhetorical lifting, with the suggestion of a location in Coventry or Warwickshire.

“Proposals in this representation … include: A fully coordinated £1.9B business growth programme across the West Midlands to improve productivity, business survival, leadership and innovation — including a regional Gigafactory and Project GREAT to enhance our automotive sector,” the document said.

“The West Midlands was at the core of the industrial revolution, and we will be at the core of the green industrial revolution… Decarbonising our industrial base is at the centre of our vision for economic recovery, including support for a Gigafactory.”

The gigafactory is also expected to help in business transformation and diversification, particularly “major inward investment and sector transformation – such as electrification of auto and aero supply chains, including a Gigafactory”.

Tesla founder Elon Musk defined a gigafactory as a “machine that builds the machine” but you could less romantically call them places to make electric batteries. Since 2016 Tesla has a 1.9M SF gigafactory at Reno, Nevada. You can see it here. Tesla has now opened four more ranging geographically from Gigafactory 3 in Shanghai to Gigafactory 4 outside Berlin. Not only are gigafactories remarkable for their size, but for their energy self-sufficiency thanks to solar and geothermal power.

Musk has been quoted saying that as many as a hundred gigafactories will be necessary to help the world move to sustainable energy consumption.

The UK might have expected to win Tesla’s European gigafactory requirement, but it went to Germany instead, and since that decision doubt has been cast on the seriousness of the UK government’s efforts to scale up battery production: relying on too few or too small gigafactories has been seen as a mistake.

The Faraday Institution estimates 130 gigawatt hours of annual capacity will be required by 2040 if the UK is to retain a large automotive sector, the Guardian reports.

Earlier this year the first serious plans for a gigafactory emerged in Scotland.