Flexible capacity to exceed 25GW in the UK by 2030

In the UK, flexible capacity from batteries, peaking plants and demand-side response is set to reach more than 25GW by 2030. That is over half of demand. And the reason is because of renewables :

The firm says the rise of intermittent renewables - which undermine the profitability of large baseload generators but still require backup power - will push annual revenues from flexibility to nearly £3 billion by the end of the next decade.

This is important because this capacity will not be as efficient as baseload generators such as combined cycle gas turbine generators. They will need to respond quicker and as a result they will have higher emissions.  So when the wind is not blowing, the grid operators will have to resort to these fast acting plant or reducing demand. It still remains to be seen how batteries will operate in practice on such a large scale. 

The same is happening here in Ireland. Capacity of demand side response units, usually diesel generators, are now at 260MW.

Full article here:

http://utilityweek.co.uk/news/flexible-capacity-to-exceed-25gw-by-2030/1316312#.Wf3-RWi0PIV

The Impact of High Levels of Wind Energy on Conventional Plant

On Wednesday 25th January 2017 wind energy reached a new record of 2,400MW for the Republic of Ireland. This post will look at the impacts on some of the other generation sources.

CCGT ( Gas)

Only three out of eight CCGT ran during the day - two in Dublin (Poolbeg and Dublin Bay) and one in Cork (Whitegate). Presumably, the other 5 plants were paid capacity or constraint payments to shut down for the day.

Wind generation was unusually stable during the day and so Dublin Bay and Whitegate mostly followed demand while the output from Poolbeg had a flat profile. Dublin Bay ran the most efficiently. Whitegate's output hovered between 45% and 60% of it's maximum (or rated capacity otherwise known as load). Poolbeg, on the other hand, operated at about a quarter of it's rated capacity. Operating a CCGT at this level leads to higher specific emissions and fuel consumption, something like driving your car in second gear all the time. 

It would have been therefore preferable to have operated Whitegate on higher loads and take Poolbeg off the grid altogether. The requirement for two power stations to be on load at all times in the Dublin area probably lead to this less than ideal situation.

Coal 

Two out of the the three generators at Moneypoint operated for the day and like the CCGT mostly followed demand.   They operated at an average of 50% of maximum output with minimum output at 40%. A load of 40% capacity is likewise not exactly ideal in terms of efficiency. 


Peat

The three peat power stations are being run on baseload and as a result are not affected by high wind levels. The biomass component seemed to be out of action. The question arises as to why (like wind) peat still receives a subsidy if it is always allowed to operate in the electricity generation market (Though I think the peat subsidy is being phased out). 


OCGT (Gas)

Both open gas cycle units at Sealrock operated at close to full output for the day as like wind they have priority dispatch in the system.


Demand Side Units (DSU)

One relatively new problem for Eirgrid is that despite having all this additional generating capacity in place, matching supply with demand is not as straightforward as previously thanks to the presence of stochastic wind energy. Fast acting plant is one answer to this. Another solution is reducing demand during periods of high demand. Demand side units reduce the demand during peak times giving industrial users a choice to shut down production or use their own diesel generators. 

As more wind is added, more reliance will be placed on DSUs and ironically diesel generation. During this day, on average 18MW per hour of DSU was called on to help keep the lights on. Not a significant amount at this stage. But according to Eirgrid :

The capacity of Demand Side Units in Ireland has increased to 230 MW, and is set to increase further. 

East West Interconnector to UK (EWIC)

The UK interconnector played a crucial role on this day. For most of the time, Ireland sent across it's surplus wind but for an hour, between 6pm and 7pm, Irish generation was insufficient to meet the rise in demand as people arrived home from work and turned their kettles and cookers on. It's an unfortunate fact that you can't "switch the wind on". Also you can't simply switch a large power station like a CCGT on. 

The preferred solution by Eirgrid, presumably because it was cheaper than the other option discussed below, was to reverse the direction of electricity in the interconnector. However, the UK was strapped for generation at this time and (incredibly) France were reliant on UK imports. A precarious situation for the UK but 120MW of spare power for Ireland is not a significant amount for a system of their size.

There is still a shortfall of about 200MW at peak time (where blue line is higher than orange line in the second graph above) which I'm not sure how they made up. Possibly more hydro or DSU or some other peaking plant that I may have missed.

The other option available to Eirgrid would have been to simply increase output from Poolbeg as the demand began to rise. After all, it was being operated at well below optimum efficiency as discussed above.  This is presumably what would have happened if there was no interconnector. Usually the low cost of power purchased from UK would make importing a cheaper option but I can't imagine a grid with such a tight capacity margin as the UK's giving away low cost power during peak demand times. But I can only assume it was somehow cheaper in this case.


The power UK sent to Ireland was made up mainly of gas and coal generation with some nuclear and wind : 

The generation mix for the day is given below  :

Will The Lights Stay on in Ireland ?

A new report by the European Network of Grid Operators (ENTSOE) has shown that Great Britain may not have sufficient electricity generation capacity by 2020 to keep the lights on. This has a knock on affect here in Ireland where by 2022 it is envisaged that we will become more and more dependent on interconnectors.

ENTSOE have placed Britain at the highest risk level of grid blackouts in EU but state that expensive Capacity Mechanisms may prevent them from happening. For the layman reading, this is due to lack of investment in baseload generation - gas, coal, nuclear. Lack of sufficient baseload generation in UK means interconnectors to Ireland will lie idle (where Ireland is also strapped for reliable means of power to export to UK). 

Eirgrid this year published their generation adequacy assessments up till 2025. 

Take a look at the bottom section which excludes interconnection. Green means we have sufficient generation, red means we don't. By 2022, things start getting tight, by 2023 and 2014 we are in blackout territory, highly dependent on UK to send us spare power. 

Of course, we have spent billions on new wind farms. But as ENTSEO state :

The contribution of RES [renewables] for adequacy purposes is less than for thermal plant.

I've dealt with this concept before - capacity credit.  Wind farms don't keep the lights on, power stations do. 

There is a further problem for the Irish Grid operators - Eirgrid - and that is the new data centres that are been built around the country. They consume lots of power - Eirgrid estimate that if all the data centres that are contracted are built, they will add a whopping 1,700MW on top of peak demand of about 5,000MW. This would mean we get into the red a lot quicker. 

There is a quick fix to this, of sorts, and I hinted at it earlier - Capacity Mechanisms. This involves load shedding - paying factories large amounts of money to close for a period and / or diesel generation which can ramp up alot quicker than power stations. Ireland had about 60MW of diesel generation in 2014 (referred to as Demand Side Units), we now have 230MW ! And Eirgrid have said :

The capacity of Demand Side Units in Ireland has increased to 230 MW, and is set to increase further. 

How ironic that the green revolution, the de-carbonization of our grid, the clean, green future has lead to us using more and more diesel generation - the most polluting form of electricity production. And of course, our neighbours England are also going down this path. 

Incidentally, the data centres will have back up power in the event of widespread blackouts. No, not windmills, yes you guessed it - diesel generators. The new Apple data centre in Galway will have 18 generators with a total capacity of 288MW. The new green revolution is upon us !

Sales of Diesel Generators expected to rise in Western Europe

It's an inconvenient fact that the more intermittent renewables you install, the more fast acting generators, like diesel generators, you need to keep the lights on. The rush for green energy will have lots of unintended consequences like this.

• Global annual diesel genset capacity additions are expected to increase from 62.5 GW in 2015 to 103.7 GW in 2024, representing a 5.8% compound annual growth rate (CAGR). Meanwhile, global revenue from the installation of diesel gensets is expected to grow from $41.6 billion in 2015 to $67.9 billion in 2024. Asia Pacific is forecast to be the largest market for diesel gensets, followed by Western Europe and then North America. Leading countries for diesel genset installations include the United States, China, and India, among others.