Power Plant Performance

Load factors to end March 2004

23 July 2004

By Richard Knox

As another oil crisis again sends world leaders into impressions of newly beheaded chickens, the nuclear power industry, which might be expected to seize such an opportunity to push the obvious advantages of the technology, by and large sits and waits. If there is to be a chance to revive the nuclear power industry, you would think that nuclear vendors and operators would be doing their damnedest to prove its stability and long-term prospects. They should be forcefully demonstrating the proof of this practical means of large-scale energy production.

Instead, many of these organisations appear to be guilty of either laziness, mistaken ideas about what constitutes really commercially sensitive information, or failure to foresee where their future lies. Whatever the reason, it does not reflect the needs of the world right now! The figures published in these tables are widely used as reference and as back-up for the support of the nuclear power industry. The regular failures of a few sections of the same industry to communicate, include some that have been the most avid readers of this section of Nuclear Engineering International who have also been the worst offenders. However, we would like to offer our sincere thanks to the vast majority that provide the data for these pages with unfailing regularity.

The data for the end March 2004 quarter is missing from all Ukraine, Armenian and Lithuanian units, one each from Canada and Argentina, and nine from the USA. In the analyses that follow, these have been omitted where totals and averages are presented. The generation output data from the four Indian units marked as not available in the main table arrived too late to include in the main calculations. The data for these four units is included separately, showing the annual and lifetime load factors and cumulative generation.

In most cases there has been a small fall in performance levels compared with the year previously, but the only significant one was really in the average BWR performance, due mainly to their extensive shutdowns in Japan.

In these pages a year ago, we were comparing the changes in the top lifetime performers due to the incursion from the Korean units. This has continued to the point where half of this table is now Korean units, including the second and third positions. Even though each of the three German units in the table has increased its average lifetime load factors since a year ago, Neckar 2 and Gröhnde have been overtaken by the more than ten years younger Korean rivals. The two TVO units from Finland have also remained in this table. But still top of the table is the now almost legendary Emsland that for over 16 years has produced over 93.5% of its rated 1363MWe gross. It would be marginally encouraging for the renewable energy lobby if the entire UK installed capacity of wind power could match even half of Emsland’s capacity, and half its average output for even a few minutes, let alone 16 years!

Load factor tables

Units listed include all the reactors of 150MWe and above from which we regularly receive adequate monthly data.
Annual load factors for units over the 12 months to end March 2004, and lifetime (which are also called cumulative) load factors to end March 2004, are presented in Tables 1 and 2. The figures are calculated on the same basis as that used since early 1976 so that trends can be established.
Annual load factors are calculated by dividing the gross generation of a reactor in a one-year period by the gross capacity of the reactor (sometimes called output), as originally designed, multiplied by the number of hours in the calendar year. The figures are expressed as percentages. Where a plant is uprated, the revised capacity is used from the date of the uprating.
Similarly, lifetime (or cumulative) load factors are calculated by dividing the gross generation from the date of first synchronisation (not the date of commercial operation, which can be many months after the plant is generating power) by the gross capacity multiplied by the number of hours elapsed since the first synchronisation. These figures are also expressed as percentages.
It is important to note that load factors alone can be a misleading measure of performance, for example when a utility is deliberately operating reactors below their full capacity, for load following or where hydropower is available and is used preferentially.
Figure 1 shows how the average load factors for the six main reactor types have changed over the years. Figure 2 attempts to convey the lifetime load factors for each reactor type and the amount of electricity that has been generated so far by each type. Figure 3 shows the annual and the lifetime load factors for the six main reactor types. Figure 4 conveys the country lifetime average load factors and lifetime nuclear generation for each country. Figure 5 compares the load factor average over the 12 months to end March 2004 with that for the 12 months to end March 2003, for the six main reactor types. Figure 6 shows the PWR and and the BWR averages for countries with four or more of each reactor type. Figure 7 shows load factor quartiles. Figure 8 shows the country annual average load factors over time.
In addition to Tables 1 and 2, three other tables are included: a summary of country data; the top ten reactors in terms of lifetime load factors; and the top ten reactors in terms of electricity production.

FilesTable 1

Indian units: late data
Top ten lifetime electricity generators as at end March 2004
Top ten by lifetime performance to end March 2004
Country averages as at end March 2004

End March 2004 Figure 7 End March 2004 Figure 7
End March 2004 Figure 5 End March 2004 Figure 5
End March 2004 Figure 4 End March 2004 Figure 4
End March 2004 Figure 6a End March 2004 Figure 6a
End March 2004 Figure 1 End March 2004 Figure 1
End March 2004 Figure 2 End March 2004 Figure 2
End March 2004 Figure 8 End March 2004 Figure 8
End March 2004 Figure 3 End March 2004 Figure 3
End March 2004 Figure 6b End March 2004 Figure 6b

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