With utility planning horizons extending to 2025 and beyond to meet long term renewable and climate change targets, strategies should be revisited regularly to ensure they are still on track. Changing economic, policy and other market conditions and new technologies all have an impact.
Ireland’s state owned transmission system operator (TSO) and market operator (MO) EirGrid is demonstrating this approach with its new Draft Grid Development Strategy – and all set out in a clear and easy to read document for those who are interested to comment. This is the second major review of the Grid25 strategy, which was introduced in 2008, the last being in 2011.
Ireland’s grid developments
Under the Grid25 strategy to date, EirGrid highlights the construction of over 330km of new circuits and uprating of over 1,200km of circuits. In addition, a number of new 220kV and 110kV substations are currently in the construction and energization phase. The total spent up to the end of 2013 (excluding the East West interconnector and circuits required to connect new generation stations to the grid) was €938 million.
Since 2008 the biggest change impacting the strategy has been a reduction in the projected future demand. Based on previous growth, in 2008 peak demand was projected to reach approximately 8,000MW in 2025. However, the severe recession in that year led to a marked reduction in peak demand. In the 2011 review of Grid25 a reduced demand forecast together with the use of new technologies resulted in a cost reduction from €4 billion to €3.2 billion.
Recent trends now point to steady growth in the economy and electricity use – electricity demand in Ireland has been found to closely match economic volatility. Peak demand is now projected to reach approximately 5,100MW in 2025. Coupled with this Ireland is aiming to install between 3,200MW to 3,800MW of renewable energy sources to meet a 40% renewable generation target by 2020. Much of this is necessarily located in remote parts of the country. There is also the new Energy Union 2020 10% interconnection target. [Engerati- European Energy Union Proposed To Transform Energy System]
Grid25 looking ahead
EirGrid makes clear in its draft strategy its aim to deliver best value for the Irish people, and to “do more with the existing grid and make it work harder – before building new transmission infrastructure.”
The major projects proposed are:
• North South interconnector between Woodland in County Meath and Turleenan in County Tyrone in Northern Ireland. The proposed 400kV overhead line would contribute to ensuring security of supply of electricity throughout the island of Ireland. A key benefit would be the removal of bottlenecks between the two systems and enable them to operate together as if they were one network. It would also facilitate greater connection of wind generation which would help achieve Ireland’s renewable energy targets.
• Grid West to connect renewable energies in the west of Ireland. Options include a High Voltage Direct Current (HVDC) underground cable, a 400kV High Voltage Alternating Current (HVAC) overhead line with 8km of undergrounding, or a 220kV HVAC overhead line with up to 30km of undergrounding, and analysis of these is currently under way.
• Grid Link to improve connections in the south and east of Ireland. Options include a 400kV HVAC overhead line, HVDC underground cable, or the introduction of ‘series compensation’ to the grid, and these are under evaluation.
Other projects at various stages of development are the Moneypoint-North Kerry connection to facilitate the connection of wind generation in the southwest, and grid strengthening proposals in the northwest and in west Dublin.
With these projects the final cost of Grid25 is now estimated in the range €2.7 billion to €3.9 billion.
Comprehensive grid development strategy
EirGrid believes its final grid development strategy, which will be published later in the year, will provide a comprehensive development strategy for Ireland’s electricity infrastructure.
“Grid investment will have a widespread positive impact on the Irish economy and can help reduce overall energy costs in the market,” says the company. “Investing in a modern transmission grid will put Ireland in a strong position to continue to attract foreign investment.”