Using Energy Demand Management to increase wind energy in Ireland

Wind energy currently contributes around 6.5% of the electricity generation in Ireland. The government has committed to increasing this to 33% by 2025.

That is a good thing, right? Well yes, but it brings with it some problems which will have to be addressed before it can become a reality.

In 2006 the minimum demand on the electrical grid was 1.8GW (think 4am on a summer’s morning) and the maximum demand was 5GW (winter’s evening between 5pm and 7pm).

The wind energy output during 2006 varied from 0% (on a calm day) to 0.9GW or just over 45% (think 4am in the middle of a windy night).

Projections are that by 2025 the maximum electrical demand will be 10GW and the minimum will be 3.6GW. The governments plans to increase the wind energy means that the maximum wind energy output will be 6.3GW. If this happens when the country only needs 3.6GW there will be a surplus of 2.7GW.

On the other hand if the maximum demand of 10GW happens on a calm day (not unusual) there will need to be 10GW of generating capacity on the grid.

How do we facilitate this? We can’t control the supply (the wind blows, or it doesn’t!) but we can think about starting to manage the demand.

Imagine if EirGrid, the Energy grid operator, could control the diesel generators of any companies who own them. They could switch them on, thereby reducing the overall demand on the grid at times of electrical supply shortage.

Taken a step further, if EirGrid had control of the thermostats in refrigeration plants or in the hot water tanks of larger companies, they could ratchet them up or down one or two degrees to either consume extra electricity or to reduce demand.

Taken to a logical conclusion, plug-in hybrid cars, smart domestic appliances (fridges, clothes dryers, dish washers, etc.) and central heating could all be used to help stabilise the grid and allow more wind energy come onstream.

19 thoughts on “Using Energy Demand Management to increase wind energy in Ireland”

  1. That is a good question Robin – there are two answers
    1. Cost – Turlough Hill cost £20m to build in 1968. An equivalent new pumped hydro storage site would cost billions to build. And Turlough Hill can only store a few hours worth of electricity. This is of no use when you have more than a few hours of calm and
    2. Environmental – pumped hydro storage is, at best, 75% efficient. The environmental cost (carbon footprint) of building a pumped hydro site, with enough storage capacity to meet our needs, would far outweigh the benefit.

  2. Going 100% wind-powered is worth a few billion?

    It would be a fantastic chance for Ireland as a country to lead the way.

    We should take a peninsula in South West Ireland and sacrifice it to the wind gods. Just cover the entire thing in turbines. If offshore was a possibility then that would be worth it even more (have you been under the Arklow Bank Turbins in a boat? – unreal).

    There’s a wave powered project happening in the UK called WaveHub, but will only generate 20MW

  3. Robin – going 100% wind powered isn’t a possibility. As I mentioned in the post, even when we are at 33% we will over-produce significantly at some points on windy days and we will still need to build traditional plant to cover demand on calm days.

    To get enough pumped hydro storage to cover the entire country for calm periods you would need a lake,at least the size of Lough Neagh on the top of a mountain to be the energy reservoir.

    The billions I was referring to were merely to build a new Turlough Hill.

  4. The good thing about the electrical supply network is that the generators are already set up to balance supply and demand. For example in Poolbeg the less efficient and dirtier oil generators are powered down when demand is low. This is managed from a central control which balances demand and location and tells Poolbeg how much power to supply. Surely they could integrate with Eirgrid at that central location so on windy days the traditional generators would just be told to produce less as if a phantom ESB generator was taking up the slack?

  5. The one thing that most people don’t get about wind, wave and solar is that it does not operate within the paradigm of centrally generated, country wide distributed power in the model of current power generation. Low power, long distribution lines does not play well with W/W/S when the distribution lines consume 25% of the output.

    Wind, Wave and Solar is best use regionally, decentralized and local. Smaller community based alternatively based technologies are best used in smaller installations. This does not profit energy companies as they are harder to control charge back.

    If say Sligo wanted to go wind/wave/solar it could probably achive this in one or two years. But to do the entire country, 20 to 25 years. Hence Sligo, or any other community would have to wait 20 to 25 years.

  6. @Declan – you are correct, to an extent. The generators are setup to balance supply and demand and this is managed in the NCC (National Control Centre) by Eirgrid.

    However, they can only balance so much and it can take several hours to ramp up or down these large generators. They cannot respond to sudden peaks in demand (or a drop-off in supply) quickly and this is why the ability to manage demand will prove so useful.

    @Branedy – where did you come across the figure of 25% loss over distribution lines? The only figures I am aware of indicate typical distribution losses in the order of 7%.

  7. Depending on aluminum or copper, 300KV or 500Kv, wire under wind pressure, or quality or cable splicing and age of the grid.

    You might get 7% with 500KV over aluminum in dry, calm environments, on a test grid, but wind, wave and solar has to be stepped up to 500Kv and you don’t account for transformer performance. Hence the local issue, no requirement to step up the voltage.

  8. Tom and Branedy – have you read the CAT centre’s ‘Zero carbon Britain’ report?

    It’s a fantastic report and it shows how a national grid network helps wind, wave and solar solutions. They show that at any one time round the entire UK (same for Ireland) there is always somewhere that has plenty of wind blowing, or waves etc. By creating a system that covers the whole country things become easier to balance out.

    For Ireland to achieve what they suggest is an order of magnitude easier than it would be for the UK given our small population (a 20th of the UK) and huge wind and wave resources. Strangely, having the Green’s in coalition doesn’t make me any more confident that Ireland might take steps towards leading the world in this. But just imagine how inspiring it would be if Bertie committed us to a bold and massive project to go zero carbon – it’d create loads of jobs and would give the country a much needed sense of direction and purpose (much needed now that the twin greed pillars of house prices and endless growth seem to be wobbling a bit).

  9. The question I’ve seen asked in these sorts of discussions is why is EirGrid reluctant to increase the wind generated input to their Net? They say it is due to ‘inbalance’ but Denmark, which is probably about as windy as us, has a much higher %age.

    Bye, Barry

  10. Barry,

    Denmark is connected to the European Electrical grid so if there is too much energy produced it can export it.

    We can’t export our electricity anywhere if we over-produce it. We only have one interconnect of 250MW with Northern Ireland and by the terms of that agreement, we take 200MW in from the North at night so it is of no use in stabilising the grid.

  11. So, am I being naive, should we not invest in an(other) connection and join the balancing out club?? Or, are we too far from the rest?

    OTOH, isn’t that club the reason that Germany and Belgium and others had a big drop out a while back, somebody turned off a production unit in Germany and caused half of Europe to fall over?

    Overall, we must look to find a better balance.

    Bye, Barry

  12. i have to do a debate on nuclear energy, i havt to propse that ireland shl=ould opt for it…can you help with anything good aboout it

  13. Dear Tom,
    On the subject of energy storage ,would it be posible to build a system like Turlough hill but with a much higher head of water instead of a bigger lake to store greater amount of energy.

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