Cruachan Hydroelectric Power Station removes F-gas

[Mark]

Siemens helps Cruachan Hydroelectric Power Station remove F-gas switchgear and replace with clean air technology:
https://news.siemens.co.uk/news/siemens ... spr_apid=0

Siemens has completed a major project with Drax Group to upgrade the infrastructure at the Cruachan pumped hydro storage Power Station with greener technology. Replacing equipment that was over 30 years old, the project included the UK’s first installation of four modern Siemens generator circuit breakers that do not depend on the sulphur hexafluoride (SF6) gas commonly used in switchgear at a hydro site.

SF6 is the most powerful greenhouse gas known to humanity (as such, it probably deserves a thread of its own):
https://www.bbc.co.uk/news/science-environment-49567197

[clv101]

From the Wiki:

"Was used to fill Nike Air bags in all of their shoes from 1992 to 2006.".

[Mark]

Not great by Nike, but still tiny usage in comparison with the amount used by Power & Energy companies....
https://www.grandviewresearch.com/indus ... sf6-market

[BritDownUnder]

I was impressed by the mural that is in the turbine hall at this pumped storage power station. Unbeknownst (to me anyway) it performs an essential black start function for the UK grid.



On a sadder note a surprisingly large number of workers, thirty-six, died during construction. It also has the highest staircase in the UK, about 1200 feet up in a cable duct.

[adam2]

The black start capability of this power station is indeed most important. AFAIK it has never been called upon in anger, but most important for this facility to be available.
Hydroelectric plant is often prefered for black start as very little power is required. Controls, instruments, emergency lighting, and the power operated valves to admit water to the turbines will need electricity, but this modest demand is easy to supply from batteries or diesel generators.

Black starting should only take minutes, and can be repeated many times if the grid trips during black starting. The national grid require that designated black start power stations be capable of at least three attempts at re-energising a local part of the grid.
The need to provide black start generating plant is of increasing importance due to the amount of wind and solar generation which requires an already energised system into which to feed power. The international interconectors also only work into an already energised grid system.

The run down of coal burning capacity is welcome from the enviromental point of view, but a challenge in other respects. A coal burning power station can take up to 24 hours to start from "cold and dark" If however the plant was running before the emergency, and was tripped to house load only, then full load can be supplied quickly.

There has never been a national black start in the UK, but there WAS a regional black start of the London and South East area immediatly after the great storm of 1987.

Under ordinary circumstances only about half the total water storage capacity can be used, the other half being kept in reserve for black starting or other emergency.

[Mark]

Black Start – Restarting The Grid From Scratch:
https://www.theblackoutreport.co.uk/201 ... ack-start/

Distributed ReStart Project:
https://www.nationalgrideso.com/future- ... ed-restart

Distributed ReStart is a world-first initiative. The project explores how distributed energy resources (DER) such as solar, wind and hydro, can be used to restore power to the transmission network in the unlikely event of a blackout - a process known as black start. This would remove our dependence on large and costly fossil fuel generators to provide a black start service. This ground-breaking approach would create the blueprint for international adoption.

[BritDownUnder]

I have no "hands-on" black start experience but I have heard from others on two occasions.

Once, in New Zealand, I had a tour of two power stations during a job interview, one of which was a hydro station of 4 x 25MW units. It had two small hydro generators as well which were approx 250kw each which could be started by hand as part of the black start. The water gates could be hand operated and then control power could be derived from these two to start the main four turbines. Sadly I did not get the job but it would have been very interesting.

Secondly I was working in Adelaide at a small power station and the staff narrated their experience of the South Australian blackout. Attempts to black start were not successful as the diesel generator could not start the gas turbines. During installation of a new gas turbine (that I was there for) they tested if the diesel generator could black start it and on about one in three times it could. It was interesting to see the enormous puff of black smoke issue from the diesel generator as the starting motor on the gas turbine was turned on.
I was also told that another power plant was prevented from black starting the network as the circuit breakers in the switchyard had lost their power supply.
From memory South Australia was finally black started from a feed in from the neighbouring Victoria grid.

I personally doubt that any wind farm could be used to start a grid but I am happy to be proven wrong. Batteries and solar may stand a better chance.

[adam2]

Wind power is not in general suitable for black starting a grid system.
Batteries and solar energy could in theory be used, but most are not suitable since the inverters need a functioning grid system to feed into.

Hydroelectric is arguably the best, with gas turbines also very useful. In the early stages of a black start, the frequency and voltage may vary a lot and black start plant must be able to accept this.
Coal burning plant is very slow to start and needs a lot of start up power from diesels or gas turbines, but is good at accepting abnormal operating conditions.

Cruachan and other hydroelectric plant with a black start capability is arguably becoming more important.

[BritDownUnder]

I hear that Cruachan is being upgraded to over 1GW, presumably to be available over a shorter time as there was no indication that the volumes of the reservoirs were being increased as well.

[adam2]

I hear that Cruachan is being upgraded to over 1GW, presumably to be available over a shorter time as there was no indication that the volumes of the reservoirs were being increased as well.

Splendid news. We need more of this sort of thing. Quicker starting than OCGT plant and much greener. Storage is needed for both short term demand peaks, and for sudden breakdowns of other generating plant or interconnectors.
AFAIK, the existing plant at Cruachan will remain largely as it is now, but a complete new and additional pumped storage station is to be built inside the mountain and connected to the same reservoir

An additional approx. 600 MW will greatly assist in maintaining grid stability. Had this extra capacity been available in August 2019, then the infamous power cut would probably not have occurred.

[BritDownUnder]

It is useful to do this but more storage is also needed in the longer term.

Where it will go in the UK and whether something will come up that is cheaper than pumped hydro who knows.