Is Offshore Wind the Answer ?

ESB are planning to develop a massive 330MW wind farm off the east coast of Ireland. Will offshore wind be any different to onshore wind ? The experience in Denmark should be useful. The capacity factor for offshore wind in Denmark is around 43% which means the output will certainly be much greater than onshore wind in Ireland (which has a capacity factor of about 28%). 

But will offshore wind compliment wind energy? If the peaks in offshore wind occurred during the lows in onshore wind, then that would be very useful. This would result in a smoothing out of the intermittent profile of onshore wind we are so familiar with. We could call such a renewable energy source a "complimentary source". 

An example of a strong complimentary source would be perhaps solar energy, where during hot calm conditions such as last summer, solar energy would begin to peak just as wind energy fizzles out. In this case, we could say that solar and wind are negatively correlated, which indicates that they are strong complimentary sources.

To establish whether offshore wind is a strong or weak complimentary source, we can once again look at the data from Denmark, which has about 8GW of offshore wind capacity installed. In 2017, Euan Mearns analysed three years worth of data for both offshore and onshore wind, and found that the two are well-correlated (R squared = 0.71 for hourly data, 1 is a perfect correlation). This means that offshore wind is a relatively weak complimentary source. When the wind is blowing on land, chances are it's also blowing out at sea (and vice versa). 

Hourly onshore (red) and offshore (blue) wind generation with total generation scaled up to meet total demand, Denmark, 2014-2016 (from Euan Mearns).

So this means that power stations will still need to be ramped up and down as before. Offshore wind, like onshore,  will be incapable of replacing power stations, meaning its usefulness will be limited.

References: http://euanmearns.com/can-offshore-wind-be-integrated-with-the-grid/

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. 

The Energy Bubble is Clearly Unsustainable

by Owen Martin

The Energy Regulator has reported that there is currently a backlog of 36,000MW of renewable and conventional generation connection applications (See above graph). This would increase the current capacity of 10,500MW to a staggering 46,500MW if all of these applications were accepted. As the regulator points out we only have an electricity demand for about 7,000MW. 

Under normal circumstances, only capacity that replaced existing capacity or was required to meet additional demand or reserve requirements would be accepted. Now, because of the rush to meet EU targets, thousands of megawatts of inefficient and intermittent renewable generation are being added. Renewable generation, mostly wind and solar, make up about 70% of the planned generation figure. 

This will lead to a low capacity factor across the board, with all generators operating inefficiently and intermittently. As this blog reported recently, many wind farm companies are making losses. As more generation is added, the market share for all generators will be eroded and we will see more loss making generators. Which will require yet more government intervention to keep the lights on (and possibly another NAMA to be set up).

And it gets worse. The Grid will require a large upgrade as most of these solar and wind farms will be in remote and dispersed regions far away from centres of demand. The costs will simply keep rising exponentially. 

In particular, the CRU notes that the existing backlog of connection applications amounting to 36,000MW is already significantly in excess of the all-island total electricity requirement. Keeping the non-GPA process open to further applications during the consultation period would only increase this volume. This would potentially add to consumer costs with no discernible benefit. 

 For example, with this much renewable generation, it will become increasingly difficult to stabilize and manage the grid frequency. That is why more conventional generation is required to maintain stability and of course this adds to the costs. The Regulator refers to these generators as DS3 providers and has proposed giving them priority over renewable generation :

DS3 system services are required by the system in order to accommodate increasing volumes of non-synchronous renewable generation. The CRU decided in CER/16/284 that providers of those services will be prioritised for a connection offer under the non-GPA process, and requested the system operators to develop a process for this prioritisation. 

The regulator also plans on suspending some of the renewable generation which would of course be a wise decision and be in the interests of all consumers.  Naturally, the renewable lobby groups are not happy and have somehow managed to spin this as a decision that will "result in higher electricity prices." It's difficult to understand why they are lobbying for more supply in an already over-saturated market which will erode the market share of existing renewable generators. 

The energy regulator should stick to the facts and figures as presented in her document. That way she can defend her actions later. It could be the first time an energy regulator has stood up to the green lobby and protected consumer's rights. The Energy Bubble is clearly unsustainable. I for one am hoping that for the first time in recent Irish history, an Irish regulator does the right thing before it's too late.