Energy companies have agreed to pay for a new radar system to allay Ministry of Defence concerns about the threat to national security posed by wind farms.The deal paves the way for a £7 billion investment in offshore wind turbines.

The MoD had objected to five new wind farms off the Norfolk coast, but it withdrew its opposition yesterday after an agreement between the Crown Estate and four energy companies.Plans for 924 wind turbines off the East Coast had alarmed the Royal Air Force, which said that the turbines could cause a security threat by creating blind spots in air defences.

In a landmark deal brokered by Serco, the defence services company, a Lockheed Martin TPS-77 radar system will be installed at Remote Radar Head (RRH) Trimingham in the autumn of next year to coincide with the opening of an offshore wind farm, with 88 turbines, at Sheringham Shoal.

As the number of wind farms has increased, the number of radar blackout zones has also risen. Aircraft passing through the area can disappear in the blackout and air traffic controllers can lose their position. Tests have shown that the Lockheed Martin radar can filter the movement of offshore turbines with other air and seaborne activity.

The £20 million cost of the system will be shared by the Crown Estate (which owns the seabed out to 12 nautical miles from the coastline of the UK), the Department of Energy and Climate Change and four energy companies, which are proposing to build wind farms in the Greater Wash in the next few years.

The companies are Scira Offshore Energy, which is behind the Sheringham Shoal farm; Centrica; Warwick Energy; and RWE npower renewables.Nicola Vaughan, head of aviation at RenewableUK, the trade body, said: “This was a major obstacle to offshore wind farms in the Greater Wash, which has now been lifted.”Planning applications for four further wind farms, in the line of sight of Trimingham, are expected to be brought forward. If all five farms were developed, the turbines could deliver more than 3,000 megawatts of energy — enough to power 1.7 million homes.

Project to turn CO2 into car fuel

Researchers in Bath and Bristol are working to discover if carbon dioxide extracted from air could be turned to car fuel.

A project aims to develop porous materials that can absorb CO2 and convert it into chemicals that can be used to create fuel. The idea is that the process would be powered by renewable solar energy. Bath University is working with scientists from Bristol University and the University of the West of England.

The researchers hope that in the future, the porous materials could be used to line factory chimneys to take carbon dioxide from the air, reducing the effects of climate change. 'Massive challenge' Dr Frank Marken, senior chemistry lecturer at Bath, said: "Current processes rely on using separate technology to capture and use the CO2, which makes the process very inefficient.

"By combining the processes the efficiency can be improved and the energy required to drive the CO2 reduction is minimised. "It will be a massive challenge but we have a strong team that includes chemists, chemical engineers, biologists and life cycle analysts."

The project involves researchers from Bath's Institute for Sustainable Energy and the Environment; the School of Chemistry at Bristol University; the Bristol Robotics Laboratory (BRL) and School of Life Sciences at the University of the West of England.

Dr Ioannis Ieropoulos, of BRL, said: "One of the great advantages of this project is that it will exploit the natural abilities of micro-organisms to reduce CO2 in the atmosphere and at the same time produce electricity or hydrogen as required." Dr David Fermin from the University of Bristol said: "Currently, there are no large-scale technologies available for capturing and processing CO2 from air." The £1.4m project is funded by the Engineering & Physical Sciences Research Council (EPSRC).