The Wave Hub, the £42 million "plug socket" that will be used to transfer energy generated by the seas through to the National Grid, was installed on the seabed yesterday.

The 12-tonne structure was lowered on to the seabed under 50 metres of water by a crane, 10 miles off Hayle in Cornwall, where it will create the world's largest test site for wave energy technology.

The project will see various experimental energy generators attached to the Wave Hub and begin generating power, which will be transmitted down a 25km cable back to shore.

Science Minister David Willetts said: "It is fantastic news that Wave Hub has now been deployed on the ocean floor – this ground-breaking project will strengthen the UK's position at the forefront of the wave energy sector.

"The UK is already leading the way, with 25 per cent of the world's wave and tidal technologies being developed here. This is a huge opportunity for UK business – the sector could be worth £2 billion by 2050 and it has the potential to create up to 16,000 jobs by 2040."

Actually getting the Hub to the deployment site proved problematic, with several delays involving the cable that feeds power to a transfer station on the shore. It is being buried under piles of rocks where it cannot be sunk into the seabed.

Bad weather around the coastline also hampered the team's efforts. But the device was finally lowered to the seabed at 3.15pm yesterday.

General manager Guy Lavender said: "Seeing Wave Hub lowered into the water was the culmination of more than seven years' hard work by hundreds of people and the fact that it was designed and built in this country is testimony to the skills and experience that the UK already has in the fledgling marine renewables industry.

"Wave Hub will be on the seabed for the next 25 years, helping the world gain invaluable knowledge about how we tap the vast energy potential of our oceans in the pursuit of clean, abundant, renewable energy and cementing the UK's position at the forefront of this green power revolution."

With the hub now on the seabed, specialist contractor CTC Marine will spend the next few days ensuring that the hub's four 300-metre cable "tails" which serve the four berths at Wave Hub are in the right position, and will survey the entire length of the cable.

The Nordica, the ship which deployed the hub, will then head to Portland in Dorset to pick up a 45-tonne underwater tractor to bury the 1,300 tonne sub-sea cable for a further five kilometres offshore.

Wave Hub was funded with £12.5 million from the SWRDA, £20 million from the EU Convergence Programme and £9.5 million from the government.