New Gas Plant Suffers Outage

The Waterford power station will be out of action till the end of the year

Great Island combined cycle gas powered station (CCGT) was commissioned in 2015. The power station is one of the most efficient in the country and replaced the older fuel oil plant on the same site in County Waterford.  On 25th October, it suffered a forced outage, and is expected to be offline till the end of December. Since Moneypoint is also offline at the same time, these are testing times for Eirgrid, the system operator. 

The power station has a capacity of 464MW, which leaves a capacity margin of 1,329MW from now until the week before Christmas when it's expected that two of the coal powered units at Moneypoint will be back online.

This will be the lowest capacity margin in recent years (the capacity margin is the proportion by which the total expected available generation exceeds the maximum expected level of electricity demand, at the time at which that demand occurs).  This blog recently reported that only 10% of our 2,000 or so wind turbines can be relied on over the winter period to deliver reliable power and therefore it will be fossil fuels that will be required to keep the lights on. 

It is difficult to say exactly what may have caused the outage. It can be seen in the graph below that the power station was being cycled a lot in recent times which may have added to the wear and tear on the generator's turbines.  

Leitrim Wind Farm Racks Up Losses of € 5.6 Million

Garvagh Glebe, a 26MW wind farm in Leitrim,  made a loss of € 3.5 million last year and has racked up combined losses of € 5.6 million after nine years. In 2017, it had a load factor of 23% after it's availability dropped to 59%. This means it was out of operation for 40% of the year and when it was operating only running on average at 23% of it's potential output.

The wind farm was completely dependent on funding from it's shareholder ESB to continue operating for another 12 months. This makes a complete mockery of the idea that renewables are competing against fossil fuels. ESB, which owns most of the fossil fuel power stations in the country, can only maintain investment in it's  loss making wind farms with funding from it's more profitable fossil fuel power sector. 

In 2008, during construction of the wind farm, 6,000 fish, mainly trout, were killed when tonnes of peat swept through the Owengar river which runs into Lough Allen. A similar incident occurred in Co.Galway during construction of another ESB owned Derrybrien wind farm where around 50,000 fish were killed. 

Only Ten Percent of Wind Capacity can be Relied Upon Over Winter

Eirgrid, the grid operator, have assessed that only 10% of the entire wind generation fleet in Ireland can be relied upon during the high electricity demand winter period. Solar power fares even worse as zero solar capacity can be relied on as the dark cold evenings draw in.

Conventional gas and coal generators are considered to be around 90% reliable as they can be switched on and off when called upon, once sufficient notice has been given. However, wind is unreliable in nature and is therefore given a "capacity credit" to take account of this unreliability :

 Given the variable nature of wind power, the wind capacity credit expresses how much conventional power generation can be avoided or replaced by a certain level of wind power. 

Only 476MW out of a total of 4,617MW or about 10% can be relied upon in the event that a conventional generator fails :

When it comes to keeping the lights on there is no room for the hyperbole and feel good talk that permeates much of the debate around renewables in the media and in the chambers of the Irish parliament.

The spare generating capacity above electricity demand is called the capacity margin. It has halved from 3,199MW in 2016 to 1,793MW in 2018. Two gas powered generators have closed down in 2018 and Moneypoint coal power station has suffered an outage. 

Generators shut down	Output MW
Aghada AD1 (gas fired steam turbine)	258MW
Marina (open cycle gas turbine)	95MW
Moneypoint (coal)	855MW
	1,208MW

In recent days, it was gas power, the UK interconnector and "other" generators (presumably peat and oil) that ensured the lights stayed on in the absence of Moneypoint and the above units. Renewables (mostly wind energy) varied between 7% and 27% so could not be depended on. Back up power stations are still essential in a grid with large amounts of renewables.

You can also see the importance of the interconnector with the UK (EWIC). Can the UK guarantee they will have spare capacity to export electricity to Ireland ? The black line below shows the profile for coal power in the UK in recent days. As you can see, they too were having problems with their coal units.

Scotland too is in a precarious position and will likely be reliant on imports from the UK over the winter period :

At the time of writing the Torness 2 and Hunterston 3 and 4 reactors were down, leaving Scotland with only 612 MW of nuclear capacity and only 3,900 MW of dispatchable capacity to service over 4,000 MW of demand. However, all three reactors are scheduled to restart by mid-December, and any shortfalls that might occur in the meantime could probably be covered by imports from England [Euan Mearns]

If we get a very cold winter, and there are indications that a cold one is coming, the already strained grid could come under a lot of pressure as demand increases. Couple this with more generator outages, and we could be in for some big problems. This is where the demand side of the equation would become crucial - essentially disconnecting large energy users from the grid who would have to rely on their own generation i.e. diesel generators or combined heat and power. 

Essentially, a return to the pre grid times of the early 1900s, when there was a large and inefficient diesel generator in most big towns in Ireland.