I had promised in my last post to discuss power generation concepts that are important to cost analysis. I added a few pages to the site, so here goes:
- Nameplate Capacity or Rated Output for a generating plant defines how much power it generates in ideal conditions. It is not always a clean concept to apply to all generators, and can sometimes be skewed by the manufacturer for marketing purposes. Here is an in-depth discussion of nameplate capacity.
- Availability Factor is, for a given duration, the percentage of the time when the generator is available to feed its rated output to the grid (even if it does not do so). Intuitively, it is a useful concept to compare technologies – but it is difficult to measure externally, since you cannot know if the generator is not generating due to downtime or to management decisions. It is not often tracked. Here is a more thorough discussion of availability factor.
- Capacity Factor is the most important concept of the three in cost analysis. For a given duration, it is the ratio of the actual generated power divided by the output the generator would have had if it had delivered its nameplate capacity all along. It is a powerful yet treacherous concept. here is my in-depth analysis of the capacity factor, along with a bunch of pretty illustrative plots…
Enjoy, and let me know what you think!