Energy Institute

Why is our power system connected to Britain?

We have connected our power system to Britain because it:

  • Allows us to import energy when it is cheaper as we do now
  • Increases competition on the island of Ireland, driving down prices
  • Makes our electricity supply more secure with back-up sources of power

Being connected to Britain we can now import electricity when it is cheaper. If at any time our electricity is cheaper the flow could reverse and our excess electricity be exported. Thus the East-West interconnector allows us to trade electricity with Britain when it is to our advantage.

Right now we are benefitting from lower price electricity imports from Britain. Since the East-West interconnector came into operation it has supplied between 8 and 10% of Ireland’s electricity. Recent studies conclude that Irish electricity prices are 9% lower as a result of the East-West Interconnector 1.

The EU’s current ambition for the level of electricity market interconnection is 10% of the average demand in adjacent jurisdictions 2. Ireland’s interconnectedness has reached that level except to Northern Ireland. Interconnection facilitates trading, reduces or postpones the need for further investment and promotes competition helping to make electricity prices lower in both markets. For example, through winter 2014-2015 we imported cheaper electricity from Britain on most days and returned electricity at lower prices from Ireland on windy nights. This trade has lowered costs on the island of Ireland.

If we had not built the interconnector to Britain we would have had to curtail our windfarms more often and forego the economic and environmental benefits of exporting renewable power. The requirement to curtail arises when wind generators are generating more electricity than we need in Ireland; they are blocked or constrained off from the system so as not to overload it, and they are paid when this happens 3. These constraint payments have increased in recent years. With the interconnector, there is the opportunity to export an amount of this wind power to Britain rather than paying to block it or constrain it off from our grid system.