High hopes for Hornsea One as developer says its output could fill the gap left by nuclear

An offshore windfarm on the Yorkshire coast that will dwarf the world’s largest when completed is to supply its first power to the UK electricity grid this week.

The Danish developer Ørsted, which will be installing the first of 174 turbines at Hornsea One, said it was ready to step up its plans and fill the gap left by failed nuclear power schemes.

Quick guide Offshore windfarms in the UK Show Hide How important is offshore wind power to the UK energy system?

Offshore windfarms generated 8% of the UK’s electricity in 2018, according to estimates by trade body RenewableUK. The UK has more offshore wind capacity than anywhere in the world, with 37 projects made up of nearly 2,000 turbines. There is nearly 8GW of capacity today, 1.3GW of which was added in 2018. Another 5GW is already committed to. The UK has 44% of all European offshore wind power capacity. What obstacles has wind power faced?

The first subsidies awarded to offshore windfarms promised developers a guaranteed price of up to £150 per megawatt hour, or roughly three times the wholesale cost of electricity. Such steep subsidies would not be sustainable but cost reductions in the industry have seen that figure drop to as low as £57.50. The offshore wind industry has previously been criticised for not using enough UK contractors and suppliers. What is the economic benefit to the UK?

The industry employs around 11,000 people. One of the side effects of offshore wind’s growth has been an injection of money and jobs into coastal towns that in some cases have big pockets of economic deprivation. Ports have been upgraded and new maintenance facilities built, such as the one at Newhaven in East Sussex for the first windfarm in the English Channel. The different parts of turbines are made across the UK, from the Isle of Wight to Hull. What does the future hold for offshore wind power in the UK?

The industry has a target of growing today’s 8GW capacity to 30GW by 2030, which, if achieved, would see offshore wind power supplying more than a third of the UK’s electricity. The government has put a £557m pot of funding aside for subsidies for renewables in the next few years, most of which is expected to be taken up by offshore windfarms. The industry is also hoping for export opportunities for UK firms, as new markets grow in the US and Asia.

The size of the project takes the burgeoning offshore wind power sector to a new scale, on a par with conventional fossil fuel-fired power stations.

Hornsea One will cover 407 sq km, five times the size of the nearby city of Hull. At 1.2GW of capacity it will power 1m homes, making it about twice as powerful as today’s biggest offshore windfarm once it is completed in the second half of this year.

“The ability to generate clean electricity offshore at this scale is a globally significant milestone at a time when urgent action needs to be taken to tackle climate change,” said Matthew Wright, UK managing director of Ørsted, the world’s biggest offshore windfarm builder.

The power station is only the first of four planned in the area, with a green light and subsidies already awarded to a second stage due for completion in the early 2020s.

The first two phases will use 7MW turbines, which are taller than London’s Gherkin building.

But the latter stages of the Hornsea development could use even more powerful, 10MW-plus turbines. Bigger turbines will capture more of the energy from the wind and should lower costs by reducing the number of foundations and amount of cabling firms need to put into the water.

Henrik Poulsen, Ørsted’s chief executive, said he was in close dialogue with major manufacturers to use the new generation of turbines, some of which are expected to approach the height of the Shard in London, the tallest building in the EU.

The UK has a great wind resource and shallow enough seabed to exploit it, and could even “power most of Europe if it [the UK] went to the extreme with offshore”, he said.

Offshore windfarms could help ministers fill the low carbon power gap created by Hitachi and Toshiba scrapping nuclear plants, the executive suggested. “If nuclear should play less of a role than expected, I believe offshore wind can step up,” he said.

New nuclear projects in Europe had been “dramatically delayed and over budget”, he added, in comparison to “the strong track record for delivering offshore [wind]”.

The UK and Germany installed 85% of new offshore wind power capacity in the EU last year, according to industry data. The average power rating of the turbines is getting bigger too, up 15% in 2018.

The turbines for Hornsea One are built and shipped from Siemens Gamesa’s factory in Hull, part of a web of UK-based suppliers that has sprung up around the growing sector.

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Around half of the project’s transition pieces, the yellow part of the structure that connects the foundation to the tower, are made in Teesside. Many of the towers themselves are made by a firm in Campbeltown in the Scottish highlands. Altogether, about half of the components for the project are made in the UK.

Ørsted is not yet ready to bid for a share of a £60m pot of further offshore windfarm subsidies, to be auctioned by the government this summer, but expects the price to reach even more competitive levels than those seen in 2017.

Like other international energy companies, Ørsted has put in place contingency planning in event of a no-deal Brexit – but the hope is that will not come to pass. “We want a Brexit deal that will facilitate an orderly transition out of the union,” said Poulsen.