Nuclear - future for Ireland?

Very roughly speaking you need a good 200-300m or more height difference and be within twice that distance to the coast. Like the Silvermines the lower reservoir already exists but the upper one has to be build from scratch. For Silvermines they are proposing external pipes, it's way cheaper than tunnelling. Probably wouldn't get away with that as coast is scenic. Unless you use the cheap trick of hiding the pipes in a forest so they don't ruin the view.

Another scheme I saw used Poulaphouca as the lower reservoir and tunnel through to the east side of Mullaghcleevaun above Glenmacnass

https://en.wikipedia.org/wiki/Dinorwig_Power_Station - Area of natural beauty, they undergrounded everything even though it's was a post industrial landscape of an abandoned quarry.

There's 2.5GW of battery storage being looked at.

Short duration only. So in theory could handle a reactor scram. Our grid rules say that you'd have 5 seconds to from 0 to 1.2GW ie. 75% of a 1.6GW reactor. It takes 7.6 seconds minimum to fall 286 meters so you couldn't use pumped storage.

But nuclear plants can stay off line forever so you'd still need full backup at short notice and for extended periods.

By 2030 we have to reduce emissions by 80% (not 2035, not that nuclear could be build here by them)

So we'd only need 20% as much gas so less imports and gas fields last years longer. We have some gas and import the rest from the North Sea / north of Scotland and they allocated 28GW of offshore wind so far this year.

We are getting 40% of our electricity from renewables already. Installing lots more wind should easily get us to 80% in conjunction other upgrades.

If we add double our existing capacity of wind then about 60% of the time the grid could be powered from wind alone and the other 40% of the time from a mix of wind and not-wind at an average of 20% each. Initially most of that not-wind would be gas, but even gas could move to bio-methane / hydrogen.

Demand will go up for e-cars and heat pumps and data centres. Nuclear's long lead time means if we can't predict the future accurately then we either tie up huge amounts of capital in white elephants or we have a shortfall later on.

Wind is far more flexible in construction. If you build half a wind farm you get half the power. If you build half a reactor then you still have loans to pay.

Do you mean the German grid that stopped building new coal plants in 2007*, has removed most of nuclear, and handled a rapid drop of 15GW in solar because of an eclipse, and hasn't increased pumped storage much ?

Or the one with rolling blackouts ?

*Datteln 4's approval wasn't legal.

"Plans for new reactors at Vogtle in Georgia are reportedly behind schedule and overbudget"

Major construction on Vogtle began in 2012 with a $14 billion price tag and expected startup dates of 2016 and 2017. It's now close to £30Bn and with startup dates of 2023. It's 2.2 GW

The latest delay is because workers noticed that “tens of thousands” of critical inspection records were missing or incomplete when they were preparing to send them to the federal safety regulators. It's going to cost $920m because no one heard of ISO 9000 or no checked the records before ?

"The government hopes to have a new reactor approved each year until 2030 with the aim to have them up and running by 2050"

By which time all the decision makers will have safely retired. On a completely unrelated topic there is a high correlation between corrupt countries and nuclear power.

"On 18 July 2011 the House of Commons debated and approved the 6 NPSs". (Nuclear Power Stations) Since them Hinkley C is both late and over budget at £23Bn and delayed to 2026. And lots of the exiting nuclear power stations closed down they are looking for 8 instead of 6.

2050 is far enough away to justify building new gas or wind or solar now

As many as 25 of state-run utility Electricite de France SA’s 56 nuclear reactors are offline, just as overnight temperatures in most of the country are set to fall below freezing.

Wow , that's spectacular.

The promise of nuclear is that the insane costs will provide guaranteed continuity of supply. Instead you get multiple failure modes in units that are large enough to affect the grid significantly.

Point of information : Hundreds of small modular reactors have been built and operated safely since the 1950's by NATO. They have had higher production runs, standardisation and economies of scale that the people trying to sell power station reactors can only dream of. But they aren't remotely close to being cheap. The French ones use lower enrichment ~10% so that's not even an issue. The commercial ones only exist only on paper and aren't proven and won't be proven until there's a good few of them reliably in service.

Our grid can take 75% of non-synchronous electricity. The kit to take it to 95% is slowly being rolled out. That leaves us with a minimum 5% baseload demand which can be fulfilled with hydro, waste to energy, CHP, biomass etc. As Nuclear can only supply large amounts of steady baseload (while it's working) there will be no guaranteed demand for it's output by the time it's constructed. It would have to compete on the wholesale price at the time.

We can use fossil fuel for grid stabilisation near the large cities or for peaking or backup to renewables, up to an annual total of 20% of current emissions, until 2050. Nuclear can't do any of those things. And fossil fuel can be replaced by bio-fuels and hydrogen in the future.

It costs about £30 - $60 million to build hydrolyser factories per GW of annual production. That's at the level of the rounding error on the annual cost increases of Hinkley C. And as volume increases the costs of the hydrolysers is falling like solar or lithium batteries.

Hydrogen storage may not be the best or cheapest solution. Months of storage mean that even at an efficiency of 40% from solar or wind it completely undermines nuclear costs. Target for Spain is €1/MWh contracts in the foreseeable future for solar while nuclear is near €13/MWh (Hinkley C)