Energy Institute

Could we have an electricity system without transmission lines?

No we could not. The transmission lines from the Ardnacrusha hydropower station were the backbone of the emerging electricity system in 1927 and this was reinforced with the construction of a double high tension link to Dublin from Moneypoint in County Clare in 1984. Transmission lines carry the electricity from where it is generated to where it is used in the main centres of population and electricity demand.

Without transmission lines we would have many local systems similar to what we had before the ESB was created 1. Electricity prices would be higher and there would be other disadvantages;

  • Large towns would be able to meet their electricity requirements but only from a limited choice of energy sources. This would increase prices.
  • Smaller towns would have to pay more because they would miss out on the economies of scale of bigger plants and the opportunity to share standby plant costs. This would affect their prospects for economic development.
  • Rural areas would have access to restricted or expensive electricity. While local energy sources such as wind, solar and biomass could meet some of their needs, there would be a large deficit from not having a secure supply from the large power plants (gas, coal) that are far away.

More local or distributed generation is often offered as an alternative as it requires less of a grid system. However, distributed generation sources are currently expensive (fuel cells 2) or require other costly services like battery storage (for photovoltaic cells or wind) for back-up during the night, at times of high demand or for low power production on calm or cloudy days.

In some circumstances electricity cables can be routed underground but at a higher cost 3. Over long distances undergrounding can be accomplished by using high voltage direct current technology and placing alternating current inverter stations at each end. Eirgrid is considering undergrounding as one option for its GridWest project 4. Other strategies advanced by Eirgrid include overhead North-South lines and the re-engineering of other gridlinks.

While Ireland has great potential for indigenous renewable energy from sources such as wind and biomass there is still, and will be, a deficit that must be met with other more traditional sources such as gas and oil. With regional differences in the generation of electricity from such a diverse fuel mix, suitable infrastructure must be in place to ensure that consumer needs are met 5,6.