Renewables on the Irish grid

unkel · 20-02-2025 02:08PM #1

Post the Eirgrid chart here, see how low or high we can get. Currently:

Not bad, but should have been 100% on a windy and sunny day like today.

Jonathan · 20-02-2025 02:15PM

The grid SNSP limit is 75%. We need more synchronous condensers to increase that towards 100%.

the_amazing_raisin · 20-02-2025 03:16PM

https://www.boards.ie/discussion/comment/123191226#Comment_123191226

We need more things to spin!!! 😂

On a more relevant topic, I was watching a video about data centers recently and they have these almost frictionless flywheel UPS systems

It's effectively a drum held up by magnets and then spun up by an electric coil. When the power goes it switches from motor to generator and gives out power

The amount of time you can get power is only a few minutes, but you can pull several hundred kilowatts out some something the size of 3 server cabinets. They're great for sudden changes while you're waiting for a generator to cycle up and don't have enough batteries to cover the instant load

A bunch of those attached to the HV substations would probably go a long way to stabilising the grid

unkel · 20-02-2025 04:26PM

https://www.boards.ie/discussion/comment/123191499#Comment_123191499

Relatively cheap solutions like Tesla's megapacks (about €1 million each for 4MWh) have built in software that can handle grid stabilisation too

It is absurd that there are new gas peaker plants in planning and development in 2025. And even more absurd that there are calls for data centres to have their own fossil fuel on site power generation as part of future planning permission approval

graememk · 20-02-2025 04:35PM

https://www.boards.ie/discussion/comment/123191499#Comment_123191499

https://youtube.com/shorts/SUK4Og2ty1M?si=rdvhH96pQlQje1w9

"I like things that spin" ....

I think there's a few flywheels going in at powerplants for this reason

cnocbui · 20-02-2025 05:09PM

https://www.boards.ie/discussion/comment/123191809#Comment_123191809

Have you costed the batteries for running the grid for 11 days? I'd imagine that would be why they are going for gas.

CoffeeImpala · 20-02-2025 05:32PM

https://www.boards.ie/discussion/comment/123191994#Comment_123191994

unkel mentioned peaker plants. There was no mention of using batteries to power the grid 24hrs a day. Just the the few hours of peak demand.

You wouldn't run the grid for 11 days on peaker plants either because they're so inefficient.

CoffeeImpala · 20-02-2025 05:41PM

https://www.boards.ie/discussion/2058397312/renewables-on-the-irish-grid

I had spotted this and wondering where might be an appropriate place to ask. Is there an issue with the data feeds or do they have more synchronous condensers running?

It's just under 16% thermal at the moment which is the lowest I've seen. I have seen 100% renewables at times over night when we're been exporting an amount equal to the stabilisation generation.

cnocbui · 20-02-2025 05:45PM

https://www.boards.ie/discussion/comment/123192049#Comment_123192049

Ok, but the maths is likely near identical in that calculations were done that indicated renewables couldn't recharge batteries sufficiently between lulls and/or that the cost of batteries was prohibitive.

Efficient or not, a peaker plant can keep the lights on, long after batteries have gone flat. Cost is seemingly of no concern when it comes to measures required to make renewables seem viable - ER called for €100 B of expenditure on OSW, for example. Running peaker plants inefficiently is as nothing compared to that.

the_amazing_raisin · 20-02-2025 05:51PM

https://www.boards.ie/discussion/comment/123191809#Comment_123191809

There's going to be a need for thermal generation for the foreseeable future, but if we can get from 6 hours a day to 6 hours every 3 days, then to 6 hours a week that'll be a major difference

If they could co-locate the generators with some renewable thermal power like waste burning then that would be better again because it allows for more heat recycling

Even better would be if they could get gas demand down enough to enable us stockpiling biogas instead of relying on fossil fuels

It's good to have the backup power available, there'll be cluster **** periods where it'll be snowing and no wind and the UK isn't exporting

I look at it as a game of averages, fill in as much of the demand with renewables over the year as possible

CoffeeImpala · 20-02-2025 05:53PM

https://www.boards.ie/discussion/comment/123192080#Comment_123192080

Who said anything about charging the batteries from renewables. The batteries are for grid stabilisation and peak power demand so you charge them when your CCGTs have spare capacity. If there's excess renewables available that's a bonus.

CCGTs can keep the lights on as well but significantly more efficiently.

ECO_Mental · 20-02-2025 06:23PM

https://www.boards.ie/discussion/comment/123191499#Comment_123191499

https://www.siemens-energy.com/global/en/home/stories/irelands-great-grid-stabilizer.html

They have one if these in Moneypoint...one of the biggest in Europe 4000 Mega Watt Seconds...that's a new unit for me😀

graememk · 20-02-2025 07:23PM

https://www.boards.ie/discussion/comment/123192192#Comment_123192192

So.. joules? 4Gj ?

A joule is power (W) x time (s) (yes a kWh is also joules...)

the_amazing_raisin · 20-02-2025 10:21PM

https://www.boards.ie/discussion/comment/123192363#Comment_123192363

It's no kWh/h 😂

graememk · 20-02-2025 10:54PM

https://www.boards.ie/discussion/comment/123192838#Comment_123192838

And the energ ratings are close.. kWh/annum or kWh/1000h... I digress..

Works out to be 1111kWh or 1.1MWh

Anyway more things that spin. Sure the battery banks can help stabilise the grid. But they aren't instant.

The flywheels are instant as they are physically tied to the grid, like a thermal plant or hydro.

Any change in the grid the flywheel will instantly respond, giving time for the battery storage time to react.

If something happens the grid, every synchronous generator experiences it at the same time, throughout the grid.

Renewables on the Irish grid

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