Scotland has had a dreadful summer. Our rivers have been in flood for most of the year. But then along came September and with high pressure stable over the North Sea we are now enjoying an Indian Summer. And so is much of Northern Europe. This is good for the soul, but as we shall see dreadful for both wind and hydro production. We imported more electricity in September (9%) than was produced by wind (6%).
According to DECC, the UK had 10.9 GW of installed wind at end May 2015. At 08:35 on 26th September this massive wind park managed to produce 0.134 GW. That works out at 1.2% load. The maximum for the month was 5.3 GW, 48.6% load, at 06:05 on 12th September. The average wind load for the month was 16%.
Hydro has operated well below capacity all month with an average load of 9% (compare with 41% in January this year). Imports via inter-connectors have been full on all month with average load of 68%. Nuclear had average load of 74%.
According to DECC, the UK had 81 GW of generating capacity at end May of which 10.9 GW was wind. With 70.1 GW of dispatchable capacity (excluding 4 GW inter-connectors), and peak winter demand of the order 55 GW, there does not seem to be a risk of blackouts caused by lack of capacity this winter unless natural gas supplies are disrupted.
Figure 1 UK electricity supply for September 2015. Data from BM reports via Gridwatch. Click chart to get a large, readable copy. There have been three UK-wide wind lulls this month; 7th-8th, 13th to 19th and 26th to ongoing. The bulk of generation has come from nuclear, coal, gas (CCGT) and imports (see Figure 3) which are probably mainly rooted in French nuclear.
Figure 2 Same data as plotted in Figure 1, not stacked. Gas (CCGT) and coal have done the bulk of load following. Note how wind has died to near zero on three occasions.
Figure 3 Pie chart showing the share of generation by type. Other = biomass, though I’m unsure if this is pure biomass or biomass co-fired with coal.
Figure 4 The capacity numbers come from DECC dukes5_10 and are for end May 2015.
Figure 5 Maximum and minimum statistics by type. The “other” category (biomass) has been run at high capacity all month (min/max=0.6). Hydro max of 599 MW compares with installed capacity of 1742 MW. Despite the dull and wet summer, there is now a drought pending. Note how max total demand is double minimum total demand (min/max = 0.51).
The River Tay in Perthshire was once world famous for its salmon runs. The river has been in flood all summer. The river hosts several hydro schemes and is rarely this low and the sky is rarely this blue.
The view from my cottage, sunset on 30 September. We had frost this morning, 1 October.
My dogs are heavily into renewable heat.