The national grid and the energy regulator are planning to go ahead with an interconnector that will link the Irish and British electricity markets - a project valued at €300 million.  Barry O'Halloranreports.

Eirgrid, the State body responsible for the national grid which connects homes and businesses with electricity suppliers, said the Government had approved plans to go ahead with the east-west interconnector. This will link the Irish and British electricity markets via a pipe running under the Irish Sea between the Leinster coast and Wales.

Eirgrid and the Commission for Energy Regulation will manage the project jointly. They did not say yesterday how much it would cost, but previous estimates have put the price at €250 million to €300 million.

The interconnector will have the capacity to move 500 megawatts (mw) - enough energy to power 300,000 homes - between the two islands. This is 100mw more than the biggest Irish generating facilities.

It will allow power generators in both countries to sell electricity into the other market. The development is seen as central to guaranteeing security of electricity supply on the island of Ireland.

The two agencies are beginning the pre-planning work and are set to tender for contractors to build and install the interconnector later this year. The pre-planning work will involve seabed surveys to establish the best route and studies to identify suitable landfall and connection points.

It is scheduled to be up and running at some point in 2012. It will use technology known as high voltage direct current, which is already used on the interconnector linking the Antrim coast with Scotland and another joining Britain with France.

Asked if the interconnector will mean that Irish people will use more nuclear-generated electricity, an Eirgrid spokesman said yesterday it was not possible to say as this would depend on the suppliers.

Under legislation passed in 1999, it is illegal to build a nuclear-powered generator in this State. He added that the interconnector would be best positioned to take power from sources where the amount of electricity generated fluctuated, like wind farms, or can be increased easily, like gas-powered plants. "The people it is most likely to benefit will be the wind farms and the gas-fired power stations."

There is already a link between the Republic and Northern Ireland through which nuclear-generated electricity is supplied to the State. This comes to less than 0.2 per cent of total demand.