I recently came across the excellent UK renewable energy data base maintained by the Renewable Energy Foundation (REF). The data base is highly detailed with over 630,000 small and large scale generators documented based on the subsidy records. The data affords the opportunity to estimate load factors for UK wind and solar. DECC also publishes data on UK load factors (dukes6_5) which are compared with those calculated from REF data.
Solar PV UK (REF): 11.8%
Solar PV UK (DECC): 10.8%
Solar PV Scotland (REF): 9.0%
Solar PV England (REF): 11.9%
Onshore wind (REF): 26.3%
Onshore wind (DECC): 27.3%
Offshore wind (REF): 30.5%
Offshore wind (DECC): 37.3%
Generally there is good agreement between REF and DECC with the exception of offshore wind where the DECC number is significantly higher than REF. All the numbers are calculated the same way and so I simply do not understand this discrepancy. DECC and REF should seek to reconcile this.
Figures for installed capacity and production are provided for year end. What we don’t know (or at least don’t calculate) is the distribution of adding capacity with time over the year. DECC take the average of the capacity at the beginning and at the end of the year and I have done same. This is a potential source of bias. Installed capacity MW * 24 * 365 provides the maximum possible generation for the year. Actual generation / maximum possible generation provides the load factor.
The REF data are easily accessed from their web site. Click on the “Energy Data” tab. The data are archived under a number of different headings that allows the data to be interrogated in a number of different ways.
Figure 1 The REF load factors are biased higher than DECC but with no significant difference. REF = 11.8%, DECC = 10.8%.
Figure 2 As is to be expected, the load for Scottish solar is below English solar. Scotland = 9.0% and England = 11.9%.
Figure 3 As is to be expected, the load for onshore wind is lower than offshore wind. There is good agreement between REF and DECC for onshore wind; 26.3 and 27.3% respectively. But poor agreement for offshore wind; 30.5 and 37.3% respectively.