Understanding which electricity generation technologies will work in the future, requires understanding the electrical demand of Ireland. So here we go.
Ireland’s electricity demand over the course of a day is a very variable thing. I’m an engineer, and I like graphs, so… lets look at a graph.

The graph runs from midnight to midnight and shows the national electricity demand. During the middle of the night relatively electricity is being consumed, well little if you call 2700MW little (1MW = 1,000,000W). So the low electricity consumption is the same as if 27million 100W bulbs are lighting. In summer it is a bit lower. In the morning as we all get up and start making coffee and toast and the like, the amount of consumption rises dramatically. The demand levels over the course of the day level off during lunch, but rise again as the evening begins. At 6pm we’re all making tea, dinner, and watching the news, and the “Peak Demand” occurs. That means that every power station in the country is sweating. In fact the peak on this graph is almost double the low point. On the worst day this winter it hit 5000MW.
So what does this all mean – Well first of all it means that Ireland needs power stations that can ramp up and down. It also means that at 6pm electricity should have a higher value. Indeed there have been serious concerns over the past few years on the availability of power stations to meet this demand.
We could get into what this means for wind… but I think that a whole other post…
BTW thanks to Eirgrid for the graph

