Monday 26 September 2016

Grid Costs Set to Rise to Meet 2020 Targets

Grid costs will cost households and businesses an additional € 354 million next year as part of a large rollout of grid and transmission networks. The Energy Regulator explains :

The five years from 2016 to 2020 will require continued investment in the transmission system and delivering ongoing infrastructure projects. The PR3 period was characterised by the initiation of a large scale infrastructure delivery programme in order to meet 2020 renewable generation targets

So the transition to the green economy doesn't involve dismantling of the existing fossil fuel system. Instead, it means adding capacity and grid infrastructure paid for by you and me. This is fast turning into a gravy train for whoever has the best idea for extracting more money from electricity bills, or in economic terms, a bubble. 

The same is happening elsewhere in Europe. In Germany, grid costs will soon rise by a whopping 45%-80% as network infrastructure struggles to keep up with all the additional capacity :

There is no going back now. We have committed ourselves to a crazy energy policy. No wonder the European Union is no longer as popular as it used to be.

Thursday 22 September 2016

Rise in Ireland's Electricity Generation CO2 Emissions

SEAI have published the latest details on CO2 emissions in Ireland. Electricity generation emissions have risen in 2015 because of a rise in coal consumed in Moneypoint.

The graph is slightly misleading for a couple of reasons. It uses a simplified modelling system that doesn't take full account of increased cycling and ramping from back up generators. Hence the disclaimer on Page 26 :

There are clear limitations in this analysis but it does provide useful indicative results. 

The cycling effects are certainly not small as stated on Page 21 - see here for an analysis

In reality, the cycling effects increase as more wind is added so the CO2 per kWh of electricity may be fairly accurate back in say 2010 but starts getting progressively worse by 2015. 

The other problem is that by the end of 2012, the East West Interconnector was up and running sending Co2 free power to Ireland throughout 2013 and after that. This is because emissions are counted in the country of origin, in this case the UK. No account seems to be taken in the graph above of this. There is no Imports (avoided) in the legend.

Lastly, as stated recently on this blog, use of diesel generators is becoming more common with increased intermittent wind power, and is now at about 230MW capacity. I can't find any reference to them in the SEAI paper so presumably they are not included. 

Monday 12 September 2016

Over 40% of Wind Energy Shutdown Last Night


Last night, over 40% of wind energy produced was shutdown or curtailed during a spell of gale force winds across the island of Ireland. This episode clearly shows the limitations of relying too much on an intermittent source of energy like wind. Billions of euros worth of turbine installations become worthless at both low wind and at high wind.   

Figure 1

The reason for the shutdown of so many wind turbines can be clearly seen in the System Frequency charts before and after the wind shutdown. 

As the gales gathered in strength on Sunday evening, maintaining the frequency of the grid became more difficult :

Figure 2

The zig zag patterns in the Figure 2 show how frequency fluctuated between 49.9 and 50.1 Hz. The dips represent periods of too much wind when system inertia drops (due to lack of conventional generation such as coal or gas). Should frequency drop below 49.7 Hz then a blackout may occur, so Eirgrid rectified this by shutting down some of the wind and allowing more conventional generation into the system. The frequency then rises again to 50Hz. Gas turbines are forced to ramp up and down more often to maintain system stability during such periods thus pushing emissions up and negating some of the benefits of  having all the wind in the first place. 

Figure 3

Figure 3 shows what happened when over 40% of the wind output was shutdown and there was more manageable levels of wind, in this case about 1,500MW. The frequency is very stable and there is little risk of blackouts. This has been normality in the grid for many years. Compare it with Figure 2. This is the future. It will certainly test engineering skills to it's limits. Gas turbines will have to function under greater strain than before. It will cost a lot of money. There can no longer be a guarantee that the electric kettle will boil when you want it to. 

The other option Eirgrid have to maintain a stable frequency in these situations is to cut demand - which is in effect a blackout under another name. The future is renewable. The future is green. I'm at a loss to figure out how this is "progress".