The UK is lagging behind in the race to rewire the world’s power grids by investing four times more on renewable energy projects than on the electricity cables needed to connect them to the grid and consumers, according to a new report.

For every pound the UK has spent on renewables it has spent only 25p on the cables and power lines, claims the report by Bloomberg NEF, which placed the UK eighth in an index of the world’s 10 biggest energy markets.

The UK has trailed its European neighbours in Germany, Spain and Italy in constructing the electricity grids needed for a surge of projects due to its low ratio of grid investment to clean energy spending. It was also behind China, the US, Australia and Brazil in the global league table, but was rated ahead of India and Japan.

Adapting the global electricity grid for a net zero future could require investment of $21.4tn to roll out 152m km of new cables, or enough to stretch from Earth to the sun, according to the report.

The findings were published days after it was revealed that the UK had spent about £1bn so far this year paying for wind turbines to be turned off during windy weather, in part because there is not enough grid infrastructure to carry electricity from where it is generated to areas of high power demand.

The report was commissioned by ScottishPower, a company which invests in renewables and power grids as well as supplying gas and power to customers. In addition to low investment, the report blamed the sluggish process of connecting wind and solar capacity to the transmission system for the UK’s low position in the global league table.

Keith Anderson, ScottishPower’s chief executive, said the UK had been a victim of its own success in rolling out renewables faster than other countries, which had strained the grid.

“It’s creaking at the seams,” he said. “We need to play catch-up. For every pound we invest in renewable energy we should be investing at least £1 in the grid. We need to increase the overall investment in the grid, and evolve our methodology for new grid connections. To be fair to the government and the regulator, they know what needs to be done.”

Britain’s electricity system is operated by the National Energy System Operator (Neso), a publicly owned company which was formerly part of the National Grid group. National Grid continues to own and operate most of the UK’s high-voltage transmission lines alongside Scottish Power and SSE, which also run some of the UK’s smaller, regional power networks.

Lawrence Slade, the chief executive of the Energy Networks Association, which represents the UK’s electricity network operators, said the government’s planning and consenting regime remained “the biggest barrier to completing vital upgrades” of the energy grid.

“It can take a decade to consent and build a new transmission line with 70% of that time spent in planning. That’s why we were encouraged by the prime minister’s statement this week to fast-track planning for vital economic infrastructure,” he said.

A spokesperson for the regulator Ofgem said the government’s clean power by 2030 mission would require a “build-out of our electricity grids at a pace not seen in decades” while keeping costs low for customers. It promised to get rid of “unnecessary red tape” to help attract “the capital investment needed to deliver clean power”.

A government spokesperson said: “We agree our planning system needs reform to deliver clean power by 2030 – which is exactly what we’re doing. We will work with industry to rewire Britain and upgrade our outdated infrastructure to get renewable electricity on the grid.”

The spokesperson added that the government would set out details on “significant planning reforms” to support the industry in “making this once in a generation upgrade of Britain’s energy infrastructure happen”.