Ireland will require between 2.5GW and 3.5GW of offshore wind installed by 2030 to help meet the government’s target of 70% renewables, according to the chief executive of state-owned utility ESB.

Pat O’Doherty tells Recharge that this offshore surge — Ireland currently has only 25MW of offshore wind installed — would probably require offshore-only tenders in the country’s forthcoming green-energy auction system, the Renewable Electricity Support Scheme (RESS).

“We'll have 4GW of onshore wind [installed] by 2020. We need another 4-5GW of wind to make that 70% target by 2030. Probably 1.5GW of that will come from onshore, the balance [2.5-3.5GW] will have to come from offshore,” he says.

Last year, in an interview with Recharge, O’Doherty put that 2030 offshore figure at 1.5GW.

There are simply not enough available onshore wind sites left in Ireland to meet the government’s 70% target, O’Doherty explains. And to install 2.5-3.5GW of offshore wind in the next ten years, the government will have to act fast.

“Ireland is looking very closely at offshore wind. So the consenting regime, the auctioning regime and the foreshore licensing regime, all has to be worked out and it all has to be worked out very quickly,” he says.

“The government fully understands that offshore wind has to happen and has to happen quickly in Ireland. And what's happened in Germany in offshore [with zero-subsidy prices] is real evidence that offshore now it's going to be the next big play.

“Ireland now has to grow an offshore industry, build an offshore support industry, the logistics and the supply chain.”

Much of the offshore wind capacity required will be installed in the shallow waters off the windy nations east coast using fixed foundations. But there is huge potential for floating wind in the deeper waters off the west coast, where wind speeds are “much, much higher”, O’Doherty says.

“The next decade is about offshore wind on the east coast and planning for what happens on the west coast, so it's post-2030 or the back end of the 2020s when we'll see floating begin to take off on the west coast.”

ESB currently has two offshore wind projects at the design stage — the 330MW Oriel, and the 500MW Clogherhead — that are being co-developed with developer Parkwind, which operates 552MW in Belgian waters.

“So the plan for those is that they would be in commercial operation in the early 2020s, but that really depends on the consenting regime and then the RESS regime,” O’Doherty says, adding that “serious consideration” will have to be given by the government to offshore-wind-only tenders. Currently, Ireland is planning technology-agnostic tenders, which would favour cheaper onshore wind.

O’Doherty adds: “We're continuously looking for offshore projects and offshore partnerships and, at this stage, that's commercially-sensitive, so I can’t say anymore about that.”

Incorporating 4GW of variable onshore wind onto Ireland’s grid is already something of an achievement, especially when you consider that Ireland’s peak winter load is about 5.5GW. But that task will soon get even harder.

“The system operator [EirGrid] and ESB's distribution business have done a huge amount now in technological terms to integrate wind. A lot of work has gone into the design and to the operation and to automating the grid for those levels of wind,” says O’Doherty.

“Today we can get instantaneous wind penetration of 60%, and EirGrid is aiming for a system design of 75% instantaneous generation by 2020. But that number has to go close to 90% if you want to get to 70% [renewables by 2030]. So what's the solution to that? The solution to that is the interconnection [including the proposed 700MW Celtic Interconnector between Ireland and France], it’s gas turbines that can ramp up and down very, very quickly. And then, of course, better forecasting of wind.”

The gas back-up plants would need carbon capture and storage (CCS) for the Irish power sector to become 100% carbon neutral by 2050, O’Doherty explains, although he admits he is coming around to the idea of using green hydrogen as an alternative.

“Ireland cannot be carbon-free from its electricity production in 2050 without a hydrogen solution or a CCS solution or a combination," he says.

ESB is also working hard on smart grids, batteries, demand response and smart EV charging to incorporate more variable energy into the network. Electrifying heat and transport is also very much on the utility’s agenda.

But solar is unlikely to play a major role in the damp, cloudy nation. In late 2017, ESB released its Dimensions Report into Ireland’s long-term low-carbon future, which said that 4% of Ireland’s energy mix would be solar in 2050. But since then, there has been a lot more discussion about PV in Ireland. ESB is now offering solar panels and services to businesses, and is doing pre-engineering studies for utility-scale PV projects, which will be dependent on the RESS regime.

“Ireland ultimately is not southern Europe and we think that there is a limit [to the use of solar power] and whether it's 4% or 50% more than that [ie, 6%], it's still of that magnitude, we believe.”

Wind

ESB boss: Ireland needs up to 3.5GW of offshore wind by 2030